Draft 2008 California 303(d)/305(b) Integrated Report

Supporting Information

Regional Board 6 - Lahontan Region

Water Body Name:	Amargosa River (Nevada border to Tecopa)
Water Body ID:	CAR6094200020080815123246
Water Body Type:	River & Stream

DECISION ID	11813
Pollutant:	1, 1, 2-trichloro-1, 2, 2-trifluoroethane | 1, 1-dichloroethane | 2, 4 D methyl ester / 2,4-Dichlorophenoxyacetic acid methyl ester | 2, 4 DB / 4-(2,4-dichlorophenoxy) butyric acid | 2,4-D (2,4-Dichlorophenoxy acetic acid) | 2-Methyl-4-chlorophenoxyacetic acid (MCPA):acetic acid | 2-chloro-4-isopropylamino-6-amino-s-triazine | 2-chloro-6-ethylamino-4-amino-s-triazine | 3-ketocarbofuran | 4(4 chloro-2-methyl phenoxy (MCPB)) butanoic acid | Aciflorfen | Aldicarb | Aldicarb sulfone | Aldicarb sulfoxide | Bendiocarb | Benomyl | Bensulfuron | Bentazon | Bromacil | Bromoxynil | Carbofuran | Chloramben methyl ester | Chlorimuron | Chlorodiamino-s-triazine | Chloropyralid | Chlorothalonil | Cycloate | Dacthal monoacid | Dicamba | Dichloroprop | Diethyl ether | Diisopropyl ether | Dinoseb | Diphenamid | Diuron | Fenuron | Flometuron | Flumetsulam | Hydroxyl carbofuran | Imazaquin | Imazethapyr | Imidacloprid | Linuron | Metalaxyl | Methiocarb | Methomyl | Methyl tert-pentyl ether | Metsulfuron | N-(4-Chlorophenyl) –N’ methylurea / Monuron | Neburon | Nicosulfuron | Norflurazon | Oryzalin | Oxamyl (Vydate) | Picloram | Propham | Propiconazol | Propoxur | Siduron | Styrene | Sulfometuron | Tebuthuron | Terbacil | Tert-butyl ethyl ether | Triazone | Tribenuron | Vinyl chloride | meta-para xylenes | o-Xylene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess these pollutant. There are no applicable state or federal saltwater aquatic life standards or criteria for the listed pollutants. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy.. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy since only one sampling result is available for each pollutant. 3. There are no applicable standards or criteria for the listed pollutants and the data cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 11813

LOE ID:	25224
Pollutant:	1, 1, 2-trichloro-1, 2, 2-trifluoroethane | 1, 1-dichloroethane | 2, 4 D methyl ester / 2,4-Dichlorophenoxyacetic acid methyl ester | 2, 4 DB / 4-(2,4-dichlorophenoxy) butyric acid | 2,4-D (2,4-Dichlorophenoxy acetic acid) | 2-Methyl-4-chlorophenoxyacetic acid (MCPA):acetic acid | 2-chloro-4-isopropylamino-6-amino-s-triazine | 2-chloro-6-ethylamino-4-amino-s-triazine | 3-ketocarbofuran | 4(4 chloro-2-methyl phenoxy (MCPB)) butanoic acid | Aciflorfen | Aldicarb | Aldicarb sulfone | Aldicarb sulfoxide | Bendiocarb | Benomyl | Bensulfuron | Bentazon | Bromacil | Bromoxynil | Carbofuran | Chloramben methyl ester | Chlorimuron | Chlorodiamino-s-triazine | Chloropyralid | Chlorothalonil | Cycloate | Dacthal monoacid | Dicamba | Dichloroprop | Diethyl ether | Diisopropyl ether | Dinoseb | Diphenamid | Diuron | Fenuron | Flometuron | Flumetsulam | Hydroxyl carbofuran | Imazaquin | Imazethapyr | Imidacloprid | Linuron | Metalaxyl | Methiocarb | Methomyl | Methyl tert-pentyl ether | Metsulfuron | N-(4-Chlorophenyl) –N’ methylurea / Monuron | Neburon | Nicosulfuron | Norflurazon | Oryzalin | Oxamyl (Vydate) | Picloram | Propham | Propiconazol | Propoxur | Siduron | Styrene | Sulfometuron | Tebuthuron | Terbacil | Tert-butyl ethyl ether | Triazone | Tribenuron | Vinyl chloride | meta-para xylenes | o-Xylene
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled organic chemicals at this station on March 17, 2004 under the Region 6 SWAMP program. One sampling result was reported for each of the listed pollutants. All of these pollutants were below the detection level.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no applicable state or federal saltwater aquatic life standards or criteria for the listed pollutants. The Lahontan Basin Plan's narrative objective for pesticides provides that: "Pesticide concentrations, individually or collectively, shall not exceed the lowest detectable levels, using the most recent detection procedures available."
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sampling result was reported for each of the listed pollutants from a sample or samples collected on March 17, 2004
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	11816
Pollutant:	1, 3 -dichlorobenzene | 1, 4 -dichlorobenzene | 1,1,1-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Atrazine | Benzene | Bromoform | Carbaryl | Carbon tetrachloride | Chlorobenzene (mono) | Chlorodibromomethane | Chloroform | Dichlorobromomethane | Dichlorodifluoromethane | Dichloromethane | Ethylbenzene | Methyl Tertiary-Butyl Ether (MTBE) | Tetrachloroethylene/PCE | Toluene | Trichloroethene | Trichlorofluoromethane (CFC-11) | cis-1,2-Dichloroethylene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	These pollutants are being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. All of the samples for all of the listed pollutants were below the detection level.. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Only one sample per pollutant was available. 3. None of the single samples for each pollutant exceeded the applicable saltwater criterion and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because the applicable water quality criteria were not exceeded and the data quantity requirements of the listing policy were not met.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 11816

LOE ID:	25233
Pollutant:	1, 3 -dichlorobenzene | 1, 4 -dichlorobenzene | 1,1,1-Trichloroethane | 1,1-Dichloroethylene (DCE)/ Vinyldine Chloride | 1,2-Dichloroethylene,-trans | 1,2-Dichloropropane | Atrazine | Benzene | Bromoform | Carbaryl | Carbon tetrachloride | Chlorobenzene (mono) | Chlorodibromomethane | Chloroform | Dichlorobromomethane | Dichlorodifluoromethane | Dichloromethane | Ethylbenzene | Methyl Tertiary-Butyl Ether (MTBE) | Tetrachloroethylene/PCE | Toluene | Trichloroethene | Trichlorofluoromethane (CFC-11) | cis-1,2-Dichloroethylene
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004. Concentrations of the listed pollutants were all below the detection level.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	(In the following summary of criteria, when a single concentration is listed, it is the acute toxicity limit. When two concentrations are listed, the first number is the acute toxicity limit and the second is the chronic toxicity limit. U.S. Environmental Protection Agency (USEPA) national recommended saltwater aquatic life criteria for the following pollutants are as follows: atrazine, 760 ug/L/17 ug/L; carbaryl, 0.81 ug/L/0.81 ug/L; methyl tertiary butyl ether (MTBE), 53,000 ug/L/ 18,000 ug/L. The USEPA saltwater "Lowest Observed Effect Level" (LOEL) criteria are as follows: 1, 1, 1 trichloroethane, 31,200 ug/L; 1,1 dichloroethene, 224, 000 ug/L; 1, 2 dichloropropane, 10,300 ug/L; 1, 3 dichlorobenzene, 1970 ug/L/129 ug/L; 1, 4 dichlorobenzene, 1970 ug/L/ 129 ug/L; benzene, 5100 ug/L; bromodichloromethane, 12,000 ug/L/6400 ug/L; chlorobenzene 160 ug/L/129 ug/L. Also, the Lahontan Basin Plan's narrative objective for pesticides provides that: "Pesticide concentrations, individually or collectively, shall not exceed the lowest detectable levels, using the most recent detection procedures available."
Objective/Criterion Reference:	National recommended water quality criteria: 2002. EPA-822-R-02-047 Washington, D.C. USEPA
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
	Quality Criteria for Water 1986. United States Environmental Protection Agency. Office of Water. Regulations and Standards. Washington D.C. EPA 440/5-86-001.
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sample for each of the 24 listed pollutants was collected on March 17, 2004.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	16129
Pollutant:	Alkalinity, Carbonate as CaCO3
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Only one sample per year was taken. 3. There are no applicable water quality standards or criteria and the data cannot be assessed using Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 16129

LOE ID:	9063
Pollutant:	Alkalinity, Carbonate as CaCO3
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Alkalinity values in two samples, measured by incremental titration, were 1180 and 960 mg/L CaCO3.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	The USEPA's national water quality criteria recommend a minimum hardness of 20 mg/L calcium carbonate as a chronic criterion for the protection of aquatic life in fresh waters, unless the natural alkalinity level is lower. There are applicable water quality standards or criteria for alkalinity in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sample was collected on March 17, 2004 and one on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12126
Pollutant:	Aluminum
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Three lines of evidence, consisting of one or two samples each, are available in the administrative record to assess this pollutant. There are no applicable saltwater aquatic life standards or criteria for aluminum in inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. A single sample per year is not temporally representative. 3. There are no applicable water quality standards or criteria and the data cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12126

LOE ID:	24940
Pollutant:	Aluminum
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Concentrations of total aluminum in the two samples were 2810 and 633 ug/L..
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no applicable state or federal saltwater standards or criteria for total aluminum.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24805
Pollutant:	Aluminum
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of aluminum was 6.1 percent dry weight.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for aluminum in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24939
Pollutant:	Aluminum
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Dissolved aluminum concentrations in the two samples were both estimates.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no applicable state or federal saltwater standards or criteria for dissolved aluminum.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12131
Pollutant:	Antimony
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Three lines of evidence, consisting of one or two samples each, are available in the administrative record to assess this pollutant. There are no applicable saltwater aquatic life standards or criteria for total or dissolved antimony in inland saline waters. There are no applicable standards or criteria for antimony in sediment of inland saline waters; the marine/estuarine sediment criterion was not exceeded. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy.. 3. There are no applicable water quality standards or criteria for antimony in inland saline waters and the data cannot be assessed using Table 3.1 of the Listing Policy. The single sediment sample did not meet the minimum sample number requirements of Table 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria..
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12131

LOE ID:	24942
Pollutant:	Antimony
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. The concentrations of total antimony in the two samples were 1.1 and 1.1 ug/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no applicable state or federal saltwater standards or criteria for total antimony.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24806
Pollutant:	Antimony
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of antimony was 1.2 ug/g (dry weight).
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for antimony in sediment in inland saline waters. The Effects Range-Median for antimony in marine and estuarine sediments is 25 ug/g dry weight; see Long et al. (1995).
Objective/Criterion Reference:	Incidence of adverse biological effects within ranges of chemical concentrations in marine and estuary sediments. Environmental Management. 19, (1): 81-97
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24941
Pollutant:	Antimony
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. The concentrations of dissolved antimony in the two samples were 1.51 and 1.2 ug/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no applicable state or federal saltwater standards or criteria for dissoved antimony.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12905
Pollutant:	Arsenic
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Three lines of evidence are available in the administrative record to assess this pollutant, for total and dissolved arsenic and arsenic in sediment. The Amargosa River is not designated for the Municipal and Domestic supply beneficial use. There are no saltwater aquatic life standards or criteria for total arsenic or arsenic in sediment. The two dissolved arsenic samples exceed the California Toxics Rule saltwater aquatic life criteria. However listiing is not recommended because: (1) Arsenic in this watershed comes from natural geological sources, including volcanic, geothermal and evaporite sources. (The Lahontan Water Board briefly maintained an NPDES permit for waste brine from a small scale water treatment plant, serviing about 150 people in the community of Shoshone. This brine contained naturally occurring arsenic from a source water spring. The NPDES permit has since been rescinded since the discharge was transferred to land.) (2) The California Toxics Rule saltwater aquatic life standards were developed using toxicity tests on marine and estuarine organisms and are not appropriate for inland saline waters. (3) The water samples were collected during March in two consecutive years and do not capture seasonal and annual variability in flows and arsenic concentrations. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. (Only one water sample per year was collected.) 3. Two out of two water samples exceeded the California Toxics Rule standards and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. However, listing is not appropriate for the reasons listed above. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because, although the California Toxics Rule standards are being exceeded, the pollutant is from natural sources, the standards are inappropriate for inland saline waters, and the data are not temporally representative.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12905

LOE ID:	24807
Pollutant:	Arsenic
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of arsenic was 13 ug/g (dry weight).
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for arsenic in sediment in inland saline waters. The Effects Range-Median for arsenic in marine and estuarine sediments is 70 ug/g dry weight; see Long et al. (1995).
Objective/Criterion Reference:	Incidence of adverse biological effects within ranges of chemical concentrations in marine and estuary sediments. Environmental Management. 19, (1): 81-97
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24944
Pollutant:	Arsenic
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Concentrations of total arsenic in the two samples were 695 and 568 ug/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal saltwater standards or criteria for total arsenic for the protection of aquatic life.
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24943
Pollutant:	Arsenic
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	2
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Concentrations of dissolved arsenic in the two samples were 699 and 495 ug/L. Both samples exceeded the CTR standards.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	The California Toxics Rule's saltwater aquatic life standards for arsenic are an acute value of 69 ug/L and a chronic value of 36 ug/L.
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	11942
Pollutant:	Barium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence, consisting of a single sediment sample, is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria for barium in sediment of inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The single sample used does not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the single sample cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria and the minimum sample number requirements of the Listing Policy are not met.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 11942

LOE ID:	24808
Pollutant:	Barium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of barium was 800 ug/g dry weight.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for barium in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12136
Pollutant:	Beryllium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Three lines of evidence, consisting of one or two samples each, are available in the administrative record to assess this pollutant. There are no applicable saltwater aquatic life standards or criteria for beryllium in inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the data cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12136

LOE ID:	24945
Pollutant:	Beryllium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Concentrations of dissolved beryllium in the two samples were both below the detection level.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal saltwater standards or criteria for dissolved beryllium for the protection of aquatic life.
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24946
Pollutant:	Beryllium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. One of the two samples was below the detection level and the other was an estimated value.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal saltwater standards or criteria for total beryllium for the protection of aquatic life.
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24809
Pollutant:	Beryllium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of beryllium was 1.8 ug/g.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for beryllium in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12084
Pollutant:	Bicarbonate
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence, consisting of two samples, is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria for bicarbonate in inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the data cannot be assessed using Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria, and the minimum sample number requirements of the Listing Policy are not met.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12084

LOE ID:	25102
Pollutant:	Bicarbonate
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. The bicarbonate concentrations in two samples were 1200 and 681 mg/L..
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal water quality objectives or criteria for bicarbonate in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	11943
Pollutant:	Bismuth
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence, consisting of a single sediment sample, is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria for bismuth in sediment of inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the single sample cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria and the minimum sample number requirements of the Listing Policy are not met.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 11943

LOE ID:	24810
Pollutant:	Bismuth
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of bismuth was below the detection level..
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for bismuth in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	13199
Pollutant:	Boron
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria for this pollutant in inland saline waters.. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used (only one sample per year) do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the minimum sample number requirements of Table 3.1 of the Listing Policy are not met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 13199

LOE ID:	25107
Pollutant:	Boron
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. The boron concentrations in two samples were 23800 and 20300 ug/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal saltwater aquatic life standards or criteria for boron in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12150
Pollutant:	Cadmium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Three lines of evidence, consisting of one or two samples each, are available in the administrative record to assess this pollutant. There are no applicable saltwater aquatic life standards or criteria for total or dissolved cadmium in inland saline waters. The sediment criterion, based on toxicity to marine/estuarine organisms, was not exceeded. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The sediment data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria for total or dissolved cadmium in inland saline waters. The marine/estuarine sediment criterion was not exceeded but the single sample does not meet the minimum sample number requirements of Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria for cadimum in inland saline waters, and the sediment sample did not meet the minimum sample number requirements of the Listing Policy.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12150

LOE ID:	24811
Pollutant:	Cadmium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of cadmium was 0.2 ug/g (dry weight).
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for cadmium in sediment in inland saline waters. The Probable Effects Level for cadmium in marine and estuarine sediments is 4.2 ug/g dry weight; see MacDonald et al. (1996).
Objective/Criterion Reference:	Development and evaluation of sediment quality guidelines for Florida coastal waters. Ecotoxicology 5: 253-278
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24947
Pollutant:	Cadmium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. The concentrations of dissolved cadmium in the two samples were 0.18 and 0.18 ug/L
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal saltwater standards or criteria for dissolved cadmium for the protection of aquatic life.
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24948
Pollutant:	Cadmium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. The concentrations of total cadmium in the two samples were 0.16 and 0.18 ug/L
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal saltwater standards or criteria for total cadmium for the protection of aquatic life.
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12911
Pollutant:	Caffeine
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. There are no applicable water quality standards or citeria for caffeine. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The single sample does not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable standards or criteria and the data cannot be assessed using Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12911

LOE ID:	25411
Pollutant:	Caffeine
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 under the Region 6 SWAMP program.. One sample had an estimated concentration of caffeine.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for caffeine.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sample was collected on March 17, 2004.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12151
Pollutant:	Calcium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Three lines of evidence, consisting of one or two samples each, are available in the administrative record to assess this pollutant. There are no applicable saltwater aquatic life standards or criteria for calcium in inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The sediment data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the data cannot be assessed using Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12151

LOE ID:	9054
Pollutant:	Calcium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Concentrations of total calcium in two samples were 19.2 and 23.3 mg/L
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for calcium.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were taken on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	9052
Pollutant:	Calcium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Concentrations of dissolved calcium in two samples were 13.4 and 26.6 mg/L
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for calcium.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were taken on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24796
Pollutant:	Calcium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of calcium was 3.6 percent dry weight.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for calcium in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	11945
Pollutant:	Carbon (inorganic)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence, consisting of a single sediment sample, is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria for inorganic carbon in the sediment of inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the single sample cannot be assessed using Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria and the minimum sample number requirements of the Listing Policy are not met.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 11945

LOE ID:	24804
Pollutant:	Carbon (inorganic)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of carbon (inorganic) was 1.3 percent dry weight.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for inorganic carbon in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	11946
Pollutant:	Carbon (organic + inorganic)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence, consisting of a single sediment sample, is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria for organic plus inorganic carbon in the sediment of inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the single sample cannot be assessed using Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria and the minimum sample number requirements of the Listing Policy are not met..
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 11946

LOE ID:	24803
Pollutant:	Carbon (organic + inorganic)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of carbon (organic + inorganic) was 1.4 percent dry weight.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for carbon in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	11948
Pollutant:	Carbon (organic)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence, consisting of a single sediment sample, is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria for organic carbon in the sediment of inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the single sample cannot be assessed using Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria and the minimum sample number requirements of the Listing Policy are not met..
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 11948

LOE ID:	25124
Pollutant:	Carbon (organic)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of carbon (organic) was 0.09 percent dry weight.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for organic carbon in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12087
Pollutant:	Carbonate
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence, consisting of two samples, is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria for carbonate in inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the data cannot be assessed using Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria, and the minimum sample number requirements of the Listing Policy are not met..
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12087

LOE ID:	9067
Pollutant:	Carbonate
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. The carbonate concentrations in two samples were 119 and 241 mg/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for carbonate in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12914
Pollutant:	Cerium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The single sample used does not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the data cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12914

LOE ID:	24812
Pollutant:	Cerium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of cerium was 71 ug/g dry weight.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for cerium in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12355
Pollutant:	Chloride
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence, consisting of two annual samples, is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria for chloride in inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria, and the two samples do not meet the minimum sample number requirements of Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria and the minimum sample number requirements of the Listing Policy are not met..
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12355

LOE ID:	25103
Pollutant:	Chloride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. The chloride concentrations in two samples were 1170 and 845 mg/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal saltwater aquatic life standards or criteria for chloride in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12152
Pollutant:	Chromium (total)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Three lines of evidence, consisting of one or two samples each, are available in the administrative record to assess this pollutant. There are no applicable saltwater aquatic life standards or criteria for chromium in inland saline waters. The California Toxics Rule standards and sediment criterion, based on toxicity to marine/estuarine organisms, were not exceeded. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The sediment data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria for inland saline waters. The marine/estuarine California Toxics Rule standards were not exceeded in two annual samples and this does not exceed the allowable frequency in Table 3.1 of the Listing Policy. The single sediment sample does not meet the minimum sample number requirements of Table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria for inland saline waters and the standards based on toxicity to marine/estuarine organisms were not exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12152

LOE ID:	24988
Pollutant:	Chromium (total)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Concentrations of total recoverable chromium in two samples were 2.1 and 1.4 ug/L. (The SWAMP data do not distinguish between trivalent and hexavalent chromium.)
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no applicable state or federal saltwater aquatic life standards or criteria for total recoverable chromium.
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24987
Pollutant:	Chromium (total)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. One of two samples was below the detection level and the dissolved chromium concentration in the other was 1.1 ug/L. (The SWAMP data do not distinguish between trivalent and hexavalent chromium.)
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	The applicable California Toxics Rule saltwater standards for dissolved chromium (total) are an acute toxicity limit of 1100 ug/L and a chronic toxicity limit of 40 ug/L.
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24813
Pollutant:	Chromium (total)
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of chromium was 23 ug/g dry weight. The SWAMP data do not distinguish between trivalent and hexavalent chromium.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for chromium in sediment in inland saline waters. The Effects Range-Median for chromium in marine and estuarine sediments is 370 ug/g dry weight; see Long et al. (1995).
Objective/Criterion Reference:	Incidence of adverse biological effects within ranges of chemical concentrations in marine and estuary sediments. Environmental Management. 19, (1): 81-97
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12137
Pollutant:	Cobalt
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Three lines of evidence, consisting of one or two samples each, are available in the administrative record to assess this pollutant. There are no applicable saltwater aquatic life standards or criteria for cobalt in inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The sediment data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the data cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12137

LOE ID:	24950
Pollutant:	Cobalt
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Concentrations of dissolved cobalt in two samples were 0.21 and 0.263 ug/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal saltwater standards or criteria for dissolved cobalt for the protection of aquatic life.
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24814
Pollutant:	Cobalt
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of cobalt was 6 ug/g dry weight.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for cobalt in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24949
Pollutant:	Cobalt
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Concentrations of total cobalt in two samples were 1.46 and 0.65 ug/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal saltwater standards or criteria for total cobalt for the protection of aquatic life.
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12915
Pollutant:	Copper
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Three lines of evidence are available in the administrative record to assess this pollutant. Two dissolved copper samples exceed the California Toxics Rule saltwater aquatic life standards. However, these standards were based on toxicity tests for marine and estuarine organisms and are not appropriate for inland saline waters.. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. (Only one water sample per year is available.) 3. Two out of two water samples exceeded the California Toxics Rule standard and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. However, listing is not recommended because the standard is inappropriate for inland saline waters and the data are not temporally representative. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because, although the California Toxics Rule standards are being exceeded, the standarda are inappropriate for inland saline waters, and the data are not temporally representative.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12915

LOE ID:	24951
Pollutant:	Copper
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	2
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Concentrations of dissolved copper in two samples were 6.6 and 6 ug/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	The California Toxics Rule saltwater standards for copper are an acute toxicity limit of 4.8 ug/L and a chronic toxicity limit of 3.1 ug/L.
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24952
Pollutant:	Copper
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Concentrations of total copper in two samples were 14.8 and 16.2 ug/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no saltwater aquatic life standards or criteria for total copper. The California Toxics Rule saltwater aquatic life standards are for dissolved copper.
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24815
Pollutant:	Copper
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of copper was 11 ug/g (dry weight).
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for copper in sediment in inland saline waters. The Effects Range-Median for copper in marine and estuarine sediments is 370 ug/g dry weight; see Long et al. (1995).
Objective/Criterion Reference:	Incidence of adverse biological effects within ranges of chemical concentrations in marine and estuary sediments. Environmental Management. 19, (1): 81-97
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12356
Pollutant:	Deuterium/Protium ratio
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisft the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the data do not meet the minimum sample number requirements of Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria and the minimum sample number requirements of the Listing Policy are not met.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12356

LOE ID:	25109
Pollutant:	Deuterium/Protium ratio
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Deuterium/protium ratios in two samples were -81.8 per mL and -84.7 per mL.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal saltwater aquatic life standards or criteria for deuterium/protium ratio in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12357
Pollutant:	Dissolved oxygen saturation
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence are available in the administrative record to assess this pollutant. Neither of the two samples exceeds the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used (two annual samples) do not satisy the data quantity requirements of section 6.1.5 of the Policy. 3. Neither of two samples exceeded the water quality objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. However, the minimum sample number requirements of Table 3.2 are not met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded and the minimum sample number requirements of the Listing Policy are not met..
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12357

LOE ID:	9021
Pollutant:	Dissolved oxygen saturation
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005. Dissolved oxygen saturation on these dates was 148 and 108 mg/L. The objective was not exceeded.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	The Lahontan Basin Plan's water quality objective states that percent saturation shall not be depressed by more than 10 percent and minimum dissolved oxygen concentration shall not be less than 80 percent saturation.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sample was collected on March 17, 2004 and one on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12916
Pollutant:	Europium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The single sample used does not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the data cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12916

LOE ID:	24816
Pollutant:	Europium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of europium was 1 ug/g dry weight.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for europium in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	13111
Pollutant:	Fecal Coliform
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.3 of the Listing Policy. Under section 3.3 a single line of evidence is necessary to assess listing status. One line of evidence consisting of a single sample is available in the administrative record to assess this pollutant. .The sample was an estimated value. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The single sample does not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. Compliance with the objective cannot be determined on the basis of the single estimated sample value, and this sample does not meet the minimum sample number requirement of Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because the minimum sample number requirements of the Listing Policy are not met.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 13111

LOE ID:	25110
Pollutant:	Fecal Coliform
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Water Contact Recreation
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 under the Region 6 SWAMP program. The fecal coliform count in the single sample was an estimated value..
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	The Lahontan Basin Plan's objective for coliform bacteria states: "Waters shall not contain concentrations of coliform organisms attributable to anthropogenic sources, including human and livestock wastes. The fecal coliform concentration during any 30-day period shall not exceed a log mean of 20/100 ml, nor shall more than 10 percent of all samples collected during any 30-day period exceed 40/100 ml. The log mean shall ideally be based on a minimum of not less than five samples collected as evenly spaced as practicable during any 30-day period. However, a log mean concentration exceeding 20/100 ml for any 30-day period shall indicate violation of this objective even if fewer than five samples were collected."
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sample was collected on March 17, 2004.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	13118
Pollutant:	Fluoride
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria for this pollutant in inland saline waters.. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used (only one sample per year) do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the minimum sample number requirements of Table 3.2 of the Listing Policy are not met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 13118

LOE ID:	25104
Pollutant:	Fluoride
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. The fluoride concentrations in two samples were 6.5 and 4.3 mg/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal saltwater aquatic life standards or criteria for fluoride in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	11988
Pollutant:	Gallium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence, consisting of a single sediment sample, is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria for gallium in sediment of inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the single sample cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria and the minimum sample number requirements of the Listing Policy are not met.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 11988

LOE ID:	24817
Pollutant:	Gallium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of gallium was 13 ug/g dry weight.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for gallium in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	16211
Pollutant:	Gold
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria.. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. (Only one sample is available.) 3. There are no applicable water quality standards or criteria and the data cannot be assessed using Table 3.1of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 16211

LOE ID:	27054
Pollutant:	Gold
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of gold in one sample was below the detection level. (Note: the SWAMP file contains two entries for "Ag" in sediment. The entry between "Ga" and "Ho" is assumed to be a typographic error for "Au" or gold, since data for gold are reported in this position for the other Amargosa River stations.)
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for gold in sediment in inland saline waters.
Objective/Criterion Reference:	Development and evaluation of sediment quality guidelines for Florida coastal waters. Ecotoxicology 5: 253-278
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	16208
Pollutant:	Gross Alpha Radioactivity
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. No biological data are available to assess whether either of the two samples exceeds the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. (Only one sample per year is available.) 3. No biological data are available for assessment of compliance and the data cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 16208

LOE ID:	27051
Pollutant:	Gross Alpha Radioactivity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Gross alpha radioactivity levels in two samples were 14 and 27 picocuries per liter (pCi/L). There are no biological data available to assess compliance with the narrative water quality objective.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal saltwater aquatic life standards or criteria specifically for gross alpha radioactivity in inland saline waters. The Lahontan Basin Plan's narrative objective for radioactivity provdes that: "Radionuclides shall not be present in concentrations which are deleterious to human, plant, animal, or aquatic life nor which result in the accumulation of radionuclides in the food web to an estent which presents a hazard to human, plant, animal or aquatic life." The objective also incorporates California Maximum Contaminant Levels for waters designated for the MUN use. MCLs do not apply to the Amargosa River.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	16226
Pollutant:	Gross Beta Radioactivity
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. No biological data are available for assessment whether either of the two samples exceeds the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Only one sample per year was collected. 3. No biological data are available for assessment of compliance with the objective and the data cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 16226

LOE ID:	27123
Pollutant:	Gross Beta Radioactivity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Gross beta radioactivity levels in two samples were 57 and 77 picocuries per liter (pCi/L). There are no biological data available to assess compliance with the narrative water quality objective.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal saltwater aquatic life standards or criteria specifically for gross beta radioactivity in inland saline waters. The Lahontan Basin Plan's narrative objective for radioactivity provdes that: "Radionuclides shall not be present in concentrations which are deleterious to human, plant, animal, or aquatic life nor which result in the accumulation of radionuclides in the food web to an estent which presents a hazard to human, plant, animal or aquatic life." The objective also incorporates California Maximum Contaminant Levels for waters designated for the MUN use. MCLs do not apply to the Amargosa River.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	16130
Pollutant:	Hardness
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. There are no applicable standards or criteria for hardness. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Only one sample per year was collected. 3. There are no applicable water quality objectives or criteria for hardness, and the data cannot be assessed using Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality objectives or criteria..
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 16130

LOE ID:	9051
Pollutant:	Hardness
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005. Hardness values in two annual samples were 69 and 180 mg/L CaCO3.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for hardness. Hardness is monitored for purposes such as determination of the applicable criteria and standards for metals whose toxicity is hardness-dependent. The U.S. Environmental Protection Agency's 1986 "Gold Book" includes generally accepted categories of hardness. Calcium and magnesium are the major ions contributing to hardness, and hardness is generally expressed as calcium carbonate. Water with a hardness equivalent to 0-75 mg equivalent CaCO3/L is considered "soft."
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Hardness was calculated for samples collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	11991
Pollutant:	Holmium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence, consisting of a single sediment sample, is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria for holmium in sediment of inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the single sample cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria and the minimum sample number requirements of the Listing Policy are not met..
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 11991

LOE ID:	24819
Pollutant:	Holmium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of holmium was below the detection level.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for holmium in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12138
Pollutant:	Iron
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Three lines of evidence, consisting of one or two samples each, are available in the administrative record to assess this pollutant. There are no applicable saltwater aquatic life standards or criteria for iron in inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The sediment data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the data cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12138

LOE ID:	24954
Pollutant:	Iron
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Concentrations of total iron in two samples were 2550 and 580 ug/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no applicable state or federal saltwater standards or criteria for total iron.
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24821
Pollutant:	Iron
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of iron was 1.7 percent dry weight.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for iron in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24953
Pollutant:	Iron
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Concentrations of dissolved iron in two samples were 40 and 10 ug/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no applicable state or federal saltwater standards or criteria for dissolved iron.
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12918
Pollutant:	Lanthanum
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The single sample used does not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the data cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12918

LOE ID:	24820
Pollutant:	Lanthanum
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of lanthanum was 38 ug/g dry weight.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for lanthanum in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12153
Pollutant:	Lead
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Three lines of evidence, consisting of one or two samples each, are available in the administrative record to assess this pollutant. There are no applicable saltwater aquatic life standards or criteria for lead in inland saline waters. The California Toxics Rule (CTR) standards and sediment criterion, both based on toxicity to marine/estuarine organisms, were not exceeded. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The sediment data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria for inland saline waters. The two available dissolved lead samples and single sdiement sample did not exceed the marine/estuarine based CTR standards and sediment criterion and this does not exceed the allowable frequency in Table 3.1 of the Listing Policy. The single sediment sample did not meet the minimum sample number requirements of Table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable standards or criteria for inland saline waters and the standards and criterion based on toxicity to marine/estuarine organisms were not exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12153

LOE ID:	24955
Pollutant:	Lead
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Concentrations of dissolved lead in two samples were 0.5 and 0.23 ug/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	The California Toxics Rule saltwater standards for lead are an acute toxicity limit of 210 ug/L and a chronic toxicity limit of 8.1 ug/L.
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24956
Pollutant:	Lead
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Concentrations of total lead in two samples were 2.71 and 1.07 ug/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no applicable state or federal saltwater standards or criteria for total lead.
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24822
Pollutant:	Lead
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of lead was 30 ug/g dry weight.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for lead in sediment in inland saline waters. The Probable Effects Level for lead in marine and estuarine sediments is 112.18 ug/g dry weight; see MacDonald et al. (1996).
Objective/Criterion Reference:	Development and evaluation of sediment quality guidelines for Florida coastal waters. Ecotoxicology 5: 253-278
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12008
Pollutant:	Lithium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence, consisting of a single sediment sample, is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria for lithium in sediment of inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the single sample cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria and the minimum sample number requirements of the Listing Policy are not met..
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12008

LOE ID:	24823
Pollutant:	Lithium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of lithium was 34 ug/g dry weight.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for lithium in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12139
Pollutant:	Magnesium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Three lines of evidence, consisting of one or two samples each, are available in the administrative record to assess this pollutant. There are no applicable saltwater aquatic life standards or criteria for magnesium in inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The sediment data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the data cannot be assessed using Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12139

LOE ID:	9056
Pollutant:	Magnesium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005. Concentrations of dissolved magnesium in two samples were 8.56 and 27 mg/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for magnesium.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were taken on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	9057
Pollutant:	Magnesium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005. Concentrations of total magnesium in two samples were 16.5 and 25.2 mg/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for magnesium.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were taken on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24799
Pollutant:	Magnesium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of magnesium was 3.6 percent dry weight.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for magnesium in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12140
Pollutant:	Manganese
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Three lines of evidence, consisting of one or two samples each, are available in the administrative record to assess this pollutant. There are no applicable saltwater aquatic life standards or criteria for manganese in inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The sediment data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the data cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12140

LOE ID:	24958
Pollutant:	Manganese
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Concentrations of dissolved manganese in two samples were 6.9 and 5 ug/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no applicable state or federal saltwater standards or criteria for dissolved manganese.
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24824
Pollutant:	Manganese
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of manganese was 540 ug/g dry weight.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for manganese in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24957
Pollutant:	Manganese
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Concentrations of total manganese in two samples were 93 and 29 ug/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no applicable state or federal saltwater standards or criteria for total manganese.
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12166
Pollutant:	Mercury
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Three lines of evidence, consisting of one or two samples each, are available in the administrative record to assess this pollutant. There are no applicable saltwater aquatic life standards or criteria for mercury in inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The sediment data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria for inland saline waters. The single sediment sample did not meet the minimum sample number requirements of Table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable standards or criteria for inland saline waters.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12166

LOE ID:	24825
Pollutant:	Mercury
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of mercury was 0.03 ug/g dry weight.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for mercury in sediment in inland saline waters.
Objective/Criterion Reference:	Pollutants of concern in Puget Sound. EPA 910/9-91-003. Seattle, WA: U.S. Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24989
Pollutant:	Mercury
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Concentrations of dissolved mercury in two samples were both below the detection level.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no applicable state or federal saltwater aquatic life standards or criteria for dissolved mercury.
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24990
Pollutant:	Mercury
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Concentrations of total recoverable mercury in two sample were 0.02 and 0.02 ug/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for mercury for protection of aquatic life in inland saline waters.
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12141
Pollutant:	Molybdenum
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Three lines of evidence, consisting of one or two samples each, are available in the administrative record to assess this pollutant. There are no applicable saltwater aquatic life standards or criteria for molybdenum in inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The sediment data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the data cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12141

LOE ID:	24960
Pollutant:	Molybdenum
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Concentrations of total molybdenum in two samples were 60 and 81.3 ug/L
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no applicable state or federal saltwater standards or criteria for total molybdenum
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24959
Pollutant:	Molybdenum
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Concentrations of dissolved molybdenum in two samples were 62. and 82.8 ug/L
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no applicable state or federal saltwater standards or criteria for dissolved molybdenum
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24826
Pollutant:	Molybdenum
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of molybdenum was 2.6 ug/g dry weight.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for molybdenum in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12919
Pollutant:	Neodymium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The single sample used does not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the data cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12919

LOE ID:	24827
Pollutant:	Neodymium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of neodymium was 30 ug/g dry weight.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for neodymium in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12169
Pollutant:	Nickel
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Three lines of evidence, consisting of one or two samples each, are available in the administrative record to assess this pollutant. There are no applicable saltwater aquatic life standards or criteria for nickel in inland saline waters. The two dissolved nickel samples did not exceed the California Toxics Rule ssaltwater aquatic life standards. Those standards are based on toxicity to marine/estuarine organisms. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The sediment data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria for inland saline waters. The two dissolved zinc samples did not exceed the California Toxics Rule standards and this does not exceed the allowable frequency in Table 3.1 of the Listing Policy. The single sediment sample did not meet the minimum sample number requirements of Table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria for inland saline waters and the standards based on marine/estuarine toxicity were not exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12169

LOE ID:	24962
Pollutant:	Nickel
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Concentrations of dissolved nickel in two samples were 1.14 and 1.11 ug/L
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	The applicable California Toxics Rule standards are an acute toxicity limit of 74 ug/L and a chronic toxicity limit of 8.2 ug/L.
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24828
Pollutant:	Nickel
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of lead was 9 ug/g dry weight.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for nickel in sediment in inland saline waters. .
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24961
Pollutant:	Nickel
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Concentrations of total nickel in two samples were 5.25 and 5.64 ug/L
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no applicable state or federal saltwater standards or criteria for total nickel.
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	11992
Pollutant:	Niobium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence, consisting of a single sediment sample, is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria for niobium in sediment of inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the single sample cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria and the minimum sample number requirements of the Listing Policy are not met.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 11992

LOE ID:	24829
Pollutant:	Niobium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of niobium was 16 ug/g dry weight.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for niobium in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12367
Pollutant:	Nitrate/Nitrite (Nitrite + Nitrate as N)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. No biological data are available for assessment whether any of the chemical samples exceeds the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy (only one sample per year is available). 3. No biological data are available for assessment of compliance with the objective and the data cannot be evaluated using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because no biological data are available for assessment of compliance with the objective..
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12367

LOE ID:	25113
Pollutant:	Nitrate/Nitrite (Nitrite + Nitrate as N)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Concentrations of nitrite plus nitrate in 2 samples were 0.011 and 0.007 mg/L
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no applicable state or federal saltwater aquatic life standards or criteria for nitrite plus nitrate. The Lahontan Basin Plan's regionwide objective for biostimulatory substances states: "Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect the water for beneficial uses."
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12368
Pollutant:	Nitrite
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. No biological data are available for assessment whether any of the chemical samples exceeds the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy (only one sample per year is available). 3. No biological data are available for assessment of compliance with the objective and the data cannot be evaluated using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because no biological data are available for assessment of compliance with the water quality objective..
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12368

LOE ID:	25114
Pollutant:	Nitrite
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Concentrations of nitrite in 2 samples were 0.005 and 0.002 mg/L
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no applicable state or federal saltwater aquatic life standards or criteria for nitrite. The Lahontan Basin Plan's regionwide objective for biostimulatory substances states: "Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect the water for beneficial uses."
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12359
Pollutant:	Oxygen 18/Oxygen 16 ratio
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence, consisting of two annual samples, is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria for this pollutant in inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria, and the two samples do not meet the minimum sample number requirements of Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria, and the minimum sample number requirements of the Listing Policy are not met.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12359

LOE ID:	25125
Pollutant:	Oxygen 18/Oxygen 16 ratio
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. The oxygen 18/oxygen 16 ratios in 2 samples were -9.31/mL and -10.17/mL.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal saltwater aquatic life standards or criteria for oxygen 1/oxygen 16 ratio in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12360
Pollutant:	Oxygen, Dissolved
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Neither of the two samples exceeds the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. Neither of 2 samples exceeded the water quality objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. However, the minimum sample number requirements of Table 3.2 are not met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded and the minimum sample number requirements of the Listing Policy are not met.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12360

LOE ID:	9020
Pollutant:	Oxygen, Dissolved
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005. The dissolved oxygen concentrations on these dates were 12.9 and 10.4 mg/L. The objective was not exceeded.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	The applicable objective from Lahontan Basin Plan Table 3-6 is a one-day minimum of 5 mg/L.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sample was collected on March 17, 2004 and one on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	16131
Pollutant:	Percent Sodium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. There are no "Percent Sodium" water quality objectives for the Amargosa River. The single sample shows a high concentration of sodium ion relative to the concentrations of calcium, magnesium, and potassium ions, indicating that it is unsuitable for for irrigated agriculture.. This is to be expected due to natural conditions in an inland saline water body. Lahontan Water Board staff are not aware of any existing use of surface water from the Amargosa River for irrigation in California. IThe Agricultural Supply use is defined to include both irrigation and livestock watering.) Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. The single sample exceeded the criterion for irrigation water and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. The minimum sample number requirements of Table 3.2 were not met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 16131

LOE ID:	25580
Pollutant:	Percent Sodium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Agricultural Supply
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004. The percent sodium value in one sample was 93 percent.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There is no site-specific water quality objective for Percent Sodium in the Amargosa River. Percent sodium is an older and now obsolete criterion for irrigation waters. It is an index for the percentage of sodium ion in the sum of the concentrations of sodium, calcium, magnesium and potassium ions. Waters with percent sodium greater than 70-75 percent were considered to be unsuitable for irrigation use.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
	Water Quality Criteria. Second Edition. California State Water Resources Control Board. Publication 3-A
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sample was taken on March 17, 2004.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not, to Lahontan Water Board staff's knowledge, used for irrigated agriculture. The intermittent and fluctuating flows would make it an unreliable supply even if water quality were not naturally poor. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12369
Pollutant:	Phosphate
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. No biological data are available for assessment whether any of the chemical samples exceeds the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy (only one sample per year is available). 3. No biological data are available for assessment of compliance with the objective and the data cannot be evaluated using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because no biological data are available for assessment of compliance with the objective..
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12369

LOE ID:	25115
Pollutant:	Phosphate
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Concentrations of phosphate in 2 samples were 0.769 and 0.727 mg/L
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no applicable state or federal saltwater aquatic life standards or criteria for phosphate in inland saline waters. The Lahontan Basin Plan's regionwide objective for biostimulatory substances states: "Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect the water for beneficial uses."
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12370
Pollutant:	Phosphorus
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. There are no applicable standards or criteria for phosphorus in sediment of inland saline waters. No biological data are available for assessment whether any of the chemical samples exceeds the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy (only one water sample per year is available, and only a single sediment sample). 3. No biological data are available for assessment of compliance with the objective and the data cannot be evaluated using Table 3.1 of the Listing Policy. . 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because no biological data are available for assessment of compliance with the water quality objective and there are no standards or criteria for assessment of the sediment sample.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12370

LOE ID:	24802
Pollutant:	Phosphorus
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of phosphorus was 0.062 percent dry weight.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for phosphorus in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	25116
Pollutant:	Phosphorus
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Concentrations of total phosphorus in two samples were 0.994 and 0.826 mg/L
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no applicable state or federal saltwater aquatic life standards or criteria for total phosphorus in inland saline waters. The Lahontan Basin Plan's regionwide objective for biostimulatory substances states: "Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect the water for beneficial uses."
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	16133
Pollutant:	Potassium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria for potassium in the water or sediment of inland saline waters.. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable standards or criteria and the data cannot be assessed using Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria..
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 16133

LOE ID:	9058
Pollutant:	Potassium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005. Concentrations of dissolved potassium in 2 samples were 54.9 and 63.1 mg/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for potassium for protection of aquatic life.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were taken on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24800
Pollutant:	Potassium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of potassium was 3 percent dry weight.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for potassium in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	16134
Pollutant:	Radium 226
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Since the Amargosa River is not designated for the MUN beneficial use, only the narrative portion of the water quality objective for radioactivity (related to beneficial use impacts) applies. No aquatic life criteria have been established for radioactivity in inland saline waters, and no biological data are available to assess beneficial use support. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Only one sample per year was collected. 3. The data are insufficient to evaluate compliance with the narrative water objective using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 16134

LOE ID:	25126
Pollutant:	Radium 226
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Radium 226 levels in two samples were 0.16 and 0.042 picocuries per liter (pCi/L). There are no biological data available to assess compliance with the narrative water quality objective.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal saltwater aquatic life standards or criteria specifically for radium 226 in inland saline waters. The Lahontan Basin Plan's narrative objective for radioactivity provdes that: "Radionuclides shall not be present in concentrations which are deleterious to human, plant, animal, or aquatic life nor which result in the accumulation of radionuclides in the food web to an estent which presents a hazard to human, plant, animal or aquatic life." The objective also incorporates California Maximum Contaminant Levels for waters designated for the MUN use. MCLs do not apply to the Amargosa River.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	11996
Pollutant:	Scandium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence, consisting of a single sediment sample, is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria for scandium in sediment of inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the single sample cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria and the minimum sample number requirements of the Listing Policy are not met..
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 11996

LOE ID:	24830
Pollutant:	Scandium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of scandium was 6 ug/g dry weight.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for scandium in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	16210
Pollutant:	Sediment
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	The Lahontan Basin Plan's narrative water quality objective is an antidegradation based objective that provides that there shall be no increases in suspended sediment concentrations or loads. This pollutant is being considered for placement on the section 303(d) list under section 3.10 of the Listing Policy, which deals with trends in water quality. One line of evidence, based on two annual samples, is available in the administrative record to assess this pollutant. It includes two suspended sediment concentration values and two suspended sediment load values calculated from instantaneous discharge measurements. Suspended sediment concentrations and loads are dependent on flows and can change rapidly over a short time during storm runoff events. Annual samples are insufficient to capture these short term events and therefore are insufficient to define natural background suspended sediment concentrations and loads, or to detect trends. Listing Policy Section 3.10 requires that natural background conditions be established. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. Sampling frequency was insufficient to establish natural background conditions and therefore does not meet the requirements of Listing Policy Section 3.10. 3. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 16210

LOE ID:	27053
Pollutant:	Sediment
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Suspended sediment concentrations in two samples were 118 and 65 mg/L. The instantaneous flow for the first date was an estimated value and that for the second date was 0.68 cubic feet per second. The calculated sediment load for the second date was 0.12 tons per day.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	The Lahontan Basin Plan's narrative objective states: "The suspended sediment load and suspended sediment discharge rate of surface waters shall not be altered in such a manner as to cause nuisance or adversely affect the water for beneficial uses."
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12142
Pollutant:	Selenium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Three lines of evidence, consisting of one sample each, are available in the administrative record to assess this pollutant. There are no applicable saltwater aquatic life criteria for selenium in inland saline waters or sediment of these waters. The California Toxics Rule standards for dissolved selenium, based on toxicity tests with marine/estuarine organisms, were not exceeded. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The sediment data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. The California Toxics Rule standards were not exceeded but the single samples in each line of evidence do not meet the minimum sample number requirements of Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because the minimum sample number requirements of the Listing Policy are not met.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12142

LOE ID:	24968
Pollutant:	Selenium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 under the Region 6 SWAMP program. The total selenium concentration in a single sample was below the detection level.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no applicable state or federal saltwater standards or criteria for total selenium.
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sample was collected on March 17, 2004.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24831
Pollutant:	Selenium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of selenium was below the detection level.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for selenium in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24966
Pollutant:	Selenium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 under the Region 6 SWAMP program.. The dissolved selenium concentration in a single sample was an estimated value.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	The applicable California Toxics Rule saltwater standards for dissolved selenium are an acute toxicity limit of 290 ug/L and a chronic toxicity limit of 71 ug/L.
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sample was collected on March 17, 2004.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12090
Pollutant:	Silica
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence, consisting of two samples, is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria for silica in inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the data cannot be assessed using Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria, and the minimum sample number requirements of the Listing Policy are not met..
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12090

LOE ID:	25105
Pollutant:	Silica
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. The silica concentrations in two samples were 74.5 and 68.9 mg/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal saltwater aquatic life standards or criteria for silica in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12170
Pollutant:	Silver
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Three lines of evidence, consisting of one or two samples each, are available in the administrative record to assess this pollutant. There are no applicable saltwater aquatic life standards or criteria for silver in inland saline waters. The California Toxics Rule standard and sediment criterion (both based on toxicity to marine/estuarine organisms) were not exceeded. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The sediment data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria for inland saline waters. The available data did not exceed the California Toxics Rule standard or the sediment criterion and this does not exceed the allowable frequency in Table 3.1 of the Listing Policy. The single sample did not meet the minimum sample number requirement of Table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria for inland saline waters and the standard and criterion based on toxicity to marine/estuarine organisms were not exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12170

LOE ID:	24970
Pollutant:	Silver
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program.. The dissolved silver concentrations in two samples were below the detection level.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	The applicable California Toxics Rule saltwater standard for dissolved silver is an acute toxicity limit of 1.9 ug/L
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004. and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24818
Pollutant:	Silver
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of silver was 0.2 ug/g. (Note: the SWAMP file contains two entries for "Ag" in sediment. The entry between "Ga" and "Ho" is assumed to be a typographic error for "Au" or gold, since data for gold are reported in this position for the other Amargosa River stations.)
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for silver in sediment in inland saline waters. The Probable Effects Level for silver in marine and estuarine sediments is 4.2 ug/g dry weight; see MacDonald et al. (1996).
Objective/Criterion Reference:	Development and evaluation of sediment quality guidelines for Florida coastal waters. Ecotoxicology 5: 253-278
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24971
Pollutant:	Silver
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program.. The concentrations of total silver in two samples were below the detection level.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no applicable state or federal saltwater standards or criteria for total silver.
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004. and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12361
Pollutant:	Sodium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria for this pollutant in inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria, and the available samples do not meet the minimum sample number requirements of Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria and the minimum sample number requirements of the Listing Policy are not met.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12361

LOE ID:	24801
Pollutant:	Sodium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of sodium was 2 percent dry weight.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for sodium in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	9060
Pollutant:	Sodium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005. Concentrations of dissolved sodium in 2 samples were 1990 and 1550 mg/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for sodium for protection of aquatic life.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were taken on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	16132
Pollutant:	Sodium Adsorption Ratio (SAR)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. . The single sample exceeds the agricultural criterion. The high level of sodium is due to evapoconcentration in a desert basin over geologic time. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. The single exceeded the criterion and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. The minimum sample number requirements of Table 3.2 were not met. 4. Sodium in this watershed comes from natural sources, and the Amargosa River is not, to Lahontan Water Board staff's knowledge, used for irrigation. 5. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because the minimum sample number requirements of the Listing Policy are not met..
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 16132

LOE ID:	25582
Pollutant:	Sodium Adsorption Ratio (SAR)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Agricultural Supply
Number of Samples:	1
Number of Exceedances:	1
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004. The SAR of one sample was 51. (As a ratio, SAR has no units.)
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	Sodium Adsorption Ratio (SAR) is a criterion for irrigation waters that has replaced Percent Sodium. It quantifies the relative proportions of sodium, calcium, and magnesium ions. SAR values greater than 9 can impose severe restrictions on the use of irrigation water due to sodium toxicity to crops.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
	Water Quality for Agriculture, Food and Agriculture Organization of the United Nations - Irrigation and Drainage Paper No. 29, Rev 1, Rome (1985)
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sample was taken on March 17, 2004.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. To Lahontan Water Board staff's knowledge, there is no use of surface waters of the Amargosa River for irrigated agriculture. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12091
Pollutant:	Specific Conductance
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence, consisting of two samples, is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria for specific conductance in inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the data cannot be assessed using Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria, and the minimum sample number requirements of the Listing Policy are not met.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12091

LOE ID:	9048
Pollutant:	Specific Conductance
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005. Specific conductance values in two annual measurements were 8210 and 6620 microsiemens per centimeter (uS/cm), reflecting the naturally saline water quality of the river.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no California or federal water quality criteria for specific conductance for the protection of aquatic life.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One measurement of specific conductance was taken on March 17, 2004 and one on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12921
Pollutant:	Strontium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The single sample used does not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the data cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12921

LOE ID:	24832
Pollutant:	Strontium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of strontium was 540 ug/g dry weight.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for strontium in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12092
Pollutant:	Sulfates
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence, consisting of two samples, is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria for sulfate in inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the data cannot be assessed using Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria, and the minimum sample number requirements of the Listing Policy are not met.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12092

LOE ID:	25106
Pollutant:	Sulfates
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. The sulfate concentrations in two samples were 1430 and 1340 mg/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal saltwater aquatic life standards or criteria for sulfate in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	11951
Pollutant:	Sulfur
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence, consisting of a single sediment sample, is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria for sulfur in the sediment of inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the single sample cannot be assessed using Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria and the minimum sample number requirements of the Listing Policy are not met..
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 11951

LOE ID:	25123
Pollutant:	Sulfur
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of sulfur was 0.07 percent dry weight.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for sulfur in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12924
Pollutant:	Tantalum
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The single sample used does not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the data cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12924

LOE ID:	24833
Pollutant:	Tantalum
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of tantalum was below the detection level.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for tantalum in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	13162
Pollutant:	Temperature, water
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	The Lahontan Basin Plan's narrative temperature objective is an antidegradation-based objective that requires that there be no change in temperature in waters designated for the Warm Freshwater Habitat (WARM) beneficial use. The objective does not include specific numerical limits for protection of the WARM use. Listing Policy Section 3.10 contains directions for assessment based on trends in water quality. These directions include requirements to establish specific baseline conditions and specify the influence of seasonal and interannual effects. One line of evidence, consisting of two annual samples, is available to support this decision. There are not enough temperature samples to establish baseline conditions (including diel, seasonal, annual and interannual variations in temperature) or to detect declining trends in the temperature regime if such trends exist.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 13162

LOE ID:	9049
Pollutant:	Temperature, water
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005. Water temperatures in two annual measurements were 18.5 and 14 degrees Celsius.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	The temperature objective in the Lahontan Basin Plan states: "The natural receiving water temperature of all waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such an alteration in temperature does not adversely affect the water for beneficial uses. For waters designated WARM, water temperature shall not be altered by more than five degrees Fahrenheit ... above or below the natural temperature. For waters designated COLD, the temperature shall not be altered. Temperature objectives for COLD interstate waters and WARM interstate waters are as specified in the 'Water Quality Control Plan for Control of Temperature in The Coastal and Interstate Waters and Enclosed Bays and Estuaries of California' including any revisions."
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One measurement of water temperature was taken on March 17, 2004 and one on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12145
Pollutant:	Thallium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Three lines of evidence, consisting of one or two samples each, are available in the administrative record to assess this pollutant. There are no applicable saltwater aquatic life standards or criteria for thallium in inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The sediment data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the data cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12145

LOE ID:	24972
Pollutant:	Thallium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program.. The concentrations of total thallium in two samples were below the detection level.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no applicable state or federal saltwater standards or criteria for total thallium in inland saline waters.
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004. and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24973
Pollutant:	Thallium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program.. One of two dissolved thallium samples was below the detection level and the other had a concentration of 0.04 ug/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no applicable state or federal saltwater standards or criteria for dissolved thallium
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004. and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24834
Pollutant:	Thallium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of thallium was below the detection level.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for thallium in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	11997
Pollutant:	Thorium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence, consisting of a single sediment sample, is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria for thorium in sediment of inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the single sample cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria and the minimum sample number requirements of the Listing Policy are not met.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 11997

LOE ID:	24835
Pollutant:	Thorium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of thorium was 10 ug/g dry weight.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for thorium in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	11956
Pollutant:	Tin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence, consisting of a single sediment sample, is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria for tin in the sediment of inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the single sample cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria and the minimum sample number requirements of the Listing Policy are not met..
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 11956

LOE ID:	24836
Pollutant:	Tin
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of tin was 2 ug/g dry weight.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for tin in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	11957
Pollutant:	Titanium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence, consisting of a single sediment sample, is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria for titanium in sediment of inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the single sample cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria and the minimum sample number requirements of the Listing Policy are not met..
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 11957

LOE ID:	24837
Pollutant:	Titanium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of titanium was 0.25 percent dry weight.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for titanium in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12097
Pollutant:	Total Dissolved Solids
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence, consisting of two samples, is available in the administrative record to assess this pollutant. (A third sample was analyzed by a different method.) There are no applicable water quality standards or criteria for total dissolved solids in inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the data cannot be assessed using Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria, and the minimum sample number requirements of the Listing Policy are not met..
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12097

LOE ID:	25108
Pollutant:	Total Dissolved Solids
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total Dissolved
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. The TDS concentrations in two sampes were 5860 and 4650 mg/L. A third value, for samples taken on March 15, 2005 was reported as "Residue", the sum of constituents. The concentration was 4530 ug/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal saltwater aquatic life standards or criteria for total dissolved solids (TDS) in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005. Residue was calculated separately from constituents sampled on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12371
Pollutant:	Total Kjeldahl Nitrogen (TKN)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. No biological data are available for assessment whether any of the chemical samples exceeds the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy (only one sample per year is available). 3. No biological data are available for assessment of compliance with the objective and the data cannot be evaluated using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because no biological data are available for assessment of compliance with the water quality objective..
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12371

LOE ID:	25112
Pollutant:	Total Kjeldahl Nitrogen (TKN)
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Concentrations of TKN in 2 samples were 1.6 and 0.86 mg/L
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no applicable state or federal saltwater aquatic life standards or criteria for total Kjeldahl nitrogen (TKN). The Lahontan Basin Plan's regionwide objective for biostimulatory substances states: "Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect the water for beneficial uses."
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	16205
Pollutant:	Triclopyr
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. The single sample does not exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. The single sample did not exceed the water quality objective and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 16205

LOE ID:	27048
Pollutant:	Triclopyr
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 under the Region 6 SWAMP program. The single sample had a triclopyr concentration below the detection level.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal saltwater aquatic life standards or criteria for the herbicide triclopyr in inland saline waters. The Lahontan Basin Plan's narrative objective for pesticides provides that: "Pesticide concentrations, individually or collectively, shall not exceed the lowest detectable levels, using the most recent detection procedures available."
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sample was collected on March 17, 2004.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	16209
Pollutant:	Tritium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One of evidence is available in the administrative record to assess this pollutant. No biological data are available to assess whether either of the two samples exceeds the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. No biological data are available for assessment of compliance with the objective and the data cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 16209

LOE ID:	27052
Pollutant:	Tritium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Tritium levels in two samples were 3 and 2.8 picocuries per liter (pCi/L). The tritium 2 sigma combined uncertainties for these data were 0.58 and 0.58 pCi/L There are no biological data available to assess compliance with the narrative water quality objective.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal saltwater aquatic life standards or criteria specifically for tritium in inland saline waters. The Lahontan Basin Plan's narrative objective for radioactivity provides that: "Radionuclides shall not be present in concentrations which are deleterious to human, plant, animal, or aquatic life nor which result in the accumulation of radionuclides in the food web to an estent which presents a hazard to human, plant, animal or aquatic life." The objective also incorporates California Maximum Contaminant Levels for waters designated for the MUN use. MCLs do not apply to the Amargosa River.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	16135
Pollutant:	Turbidity
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	Two lines of evidence are available in the administrative record to assess this pollutant. The narrative water quality objective for turbidity is antidegradation-based. The two available samples cannot be used to document baseline and trend conditions to assess compliance with the objective using Listing Policy section 3.10. (Since the two samples were taken using different methods they are not directly comparable.) Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy.. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Only one sample was collected per year. 3. The two available samples are insufficient to assess compliance with the objective under Table 3.2 or section 3.10 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 16135

LOE ID:	9065
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 under the Region 6 SWAMP program. The reported turbidity was 96 NTU. A second measurement reported as NTU was taken in 2005, but the method number indicates that it was actually in NTRU. The two types of turbidity units are not comparable.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	The Lahontan Basin Plan's regionwide objective states: "Waters shall be free of changes in turbidity that cause nuisance or adversely affect the water for beneficial uses. Increases in turbidity shall not exceed natural levels by more than 10 percent."
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One turbidity measurement was taken on March 17, 2004.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	27157
Pollutant:	Turbidity
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 15 2005 under the Region 6 SWAMP program. The reported turbidity was 24 NTU. The reported method number indicates that turbidity should probably have been reported as NTRU, as was 2005 sample for another Amargosa River station. The two types of turbidity units are not comparable.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	The Lahontan Basin Plan's regionwide objective states: "Waters shall be free of changes in turbidity that cause nuisance or adversely affect the water for beneficial uses. Increases in turbidity shall not exceed natural levels by more than 10 percent."
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One turbidity measurement was taken on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	16137
Pollutant:	Uranium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Since the Amargosa River is not designated for the MUN beneficial use, only the narrative portion of the water quality objective for radioactivity (related to beneficial use impacts) applies. No aquatic life criteria have been established for radioactivity in inland saline waters, and no biological data are available to assess beneficial use support. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Only one sediment sample was collected. 3. The data are insufficient to evaluate compliance with the narrative water objective using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 16137

LOE ID:	24842
Pollutant:	Uranium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of uranium was 2.9 ug/g dry weight.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for uranium in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12148
Pollutant:	Vanadium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Three lines of evidence, consisting of one or two samples each, are available in the administrative record to assess this pollutant. There are no applicable saltwater aquatic life standards or criteria for vanadium in inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The sediment data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the data cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12148

LOE ID:	24838
Pollutant:	Vanadium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of vanadium was 44 ug/g dry weight.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for vanadium in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24974
Pollutant:	Vanadium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. The concentrations of dissolved vanadium in two samples were 2.9 and 28.4 ug/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no applicable state or federal saltwater standards or criteria for dissolved vanadium.
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004. and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24975
Pollutant:	Vanadium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. One of two samples for total vanadium was below the detection level and the other had a concentration of 30 ug/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no applicable state or federal saltwater standards or criteria for total vanadium.
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004. and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	11998
Pollutant:	Ytterbium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence, consisting of a single sediment sample, is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria for ytterbium in sediment of inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the single sample cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria and the minimum sample numbers of the listing policy are not met..
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 11998

LOE ID:	24839
Pollutant:	Ytterbium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of ytterbium was 2 ug/g dry weight.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for ytterbium in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12002
Pollutant:	Yttrium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence, consisting of a single sediment sample, is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria for yttrium in sediment of inland saline waters. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the single sample cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria and the minimum sample number requirements of the Listing Policy are not met..
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12002

LOE ID:	24840
Pollutant:	Yttrium
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of yttrium was 16 ug/g dry weight.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for yttrium in sediment in inland saline waters.
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	12149
Pollutant:	Zinc
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Three lines of evidence, consisting of one or two samples each, are available in the administrative record to assess this pollutant. There are no applicable saltwater aquatic life standards or criteria for zinc in inland saline waters. The California Toxics Rule (CTR) saltwater standards and the sediment criterion were not exceeded. Both are based on toxicity to marine/estuarine organisms. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The sediment data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria for total zinc in inland saline waters. The CTR standards for dissolved zinc were not exceeded and this does not exceed the allowable frequency in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable standards or criteria for inland saline waters and the marine/estuarine saltwater aquatic life standards were not exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12149

LOE ID:	24841
Pollutant:	Zinc
LOE Subgroup:	Pollutant-Sediment
Matrix:	Sediment
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	1
Number of Exceedances:	0
Data and Information Type:	Chemical monitoring of sediments
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled sediment at this station on March 15, 2005 under the Region 6 SWAMP program. Results were reported as "bed sediment, smaller than 62.5 um, wet sieved, total digestion." The concentration of zinc was 48 ug/g (dry weight).
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal standards or criteria for zinc in sediment in inland saline waters. The Effects Range-Median for zinc in marine and estuarine sediments is 410 ug/g dry weight; see Long et al. (1995).
Objective/Criterion Reference:	Incidence of adverse biological effects within ranges of chemical concentrations in marine and estuary sediments. Environmental Management. 19, (1): 81-97
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sediment sample was collected on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24986
Pollutant:	Zinc
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Total
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. The concentrations of total zinc in two samples were 12 and 8 ug/L
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no applicable state or federal saltwater standards or criteria for total zinc..
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
LOE ID:	24977
Pollutant:	Zinc
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	Dissolved
Beneficial Use:	Inland Saline Water Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. The dissolved zinc concentrations two samples were 5.5 and 5.8 ug/L
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	The applicable California Toxics Rule saltwater standards for dissolved zinc are an acute toxicity limit of 90 ug/L and a chronic toxicity limit of 81 ug/L.
Objective/Criterion Reference:	Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	Two samples were collected on March 17, 2004 and March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID	13175
Pollutant:	pH
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant
Weight of Evidence:	The Lahontan Basin Plan's narrative pH objective is an antidegradation-based objective that requires that there be no change greater than 0.5 pH units in waters designated for the Cold Freshwater Habitat (COLD) or Warm Freshwater Habitat (WARM) beneficial uses. (A pH range of 6.5 to 8.5 units applies to "all other waters.") Listing Policy Section 3.10 contains directions for assessment based on trends in water quality. These directions include requirements to establish specific baseline conditions and specify the influence of seasonal and interannual effects. One line of evidence, consisting ofonly two annual samples, is available to support this decision. There are not enough pH samples to establish baseline conditions (including diel, seasonal, annual and interannual variations) or to detect changes in the pH regime due to controllable factors, if such trends exist.
RWQCB Board Decision / Staff Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 13175

LOE ID:	9046
Pollutant:	pH
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Warm Freshwater Habitat
Number of Samples:	2
Number of Exceedances:	0
Data and Information Type:	Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality:	The U.S. Geological Survey sampled this station on March 17, 2004 and March 15, 2005. Two pH measurements were taken, with values of 8.9 and 9.1 units.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	.The Lahontan Basin Plan's objective for pH states: "In fresh waters with designated beneficial uses of COLD or WARM, changes in normal ambient pH levels shall not exceed 0.5 pH units. For all other waters of the region, the pH shall not be depressed below 6.5 nor raised above 8.5 units. The Regional Board recognizes that some waters of the Region may have natural pH levels outside of the 6.5 to 8.5 range. Compliance with the pH objective for these waters will be determined on a case-by-case basis."
Objective/Criterion Reference:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at USGS Gage (Tecopa) was sampled.
Temporal Representation:	One sample was collected on March 17, 2004 and one on March 15, 2005.
Environmental Conditions:	The Amargosa River flows into California from Nevada and terminates in Death Valley. It is mostly ephemeral but there are perennial reaches. There is great seasonal and annual variability in flows. Most of the watershed is U.S. Bureau of Land Management or National Park land. The Amargosa River is not designated for the Municipal and Domestic Supply (MUN) beneficial use. The MUN use designation was removed in Basin Plan amendments that took effect in 2002. The rationale for removing the use included naturally high salinity and levels of toxic substances such as arsenic, and fluctuating water quantity that would make the river an unreliable supply if treatment were feasible. The perennial reaches of the Amargosa River and the associated riparian areas support a complex of rare, threatened or endangered fish and wildlife species. To Lahontan Water Board staff’s knowledge, there are no salmonids in the river and there is no warm water fishery for human consumption.
QAPP Information:	The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):