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

Supporting Information

Regional Board 6 - Lahontan Region

Water Body Name:	Amargosa River (Tecopa to Upper Canyon)
Water Body ID:	CAR6094200020080816182154
Water Body Type:	River & Stream

DECISION ID	12978
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 this pollutant. There are no applicable water quality standards or criteria for any of 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 single sampling result available for each pollutant 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 12978

LOE ID:	25225
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 standards or criteria for the listed pollutants.
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 Upper Canyon, 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	12981
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:	This 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 pollutants were at non-detectable levels. Under Section 6.1.5.5 of the Listing Policy, the appiicable standards are presumed to be attained.. 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 available for each pollutant does not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. None of the single samples for each pollutant exceeded the applicable standards 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 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 12981

LOE ID:	25412
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;
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 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	16212
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 collected.) 3. There are no applicable water quality standards or criteria and the data cannot be asssessed 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 16212

LOE ID:	27056
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. Two samples had alkalinities of 616 and 580 mg/L CaCO3. The criterion was not violated.
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 freshwater aquatic life, unless the natural alkalinity level is lower. There are no 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 Upper Canyon, 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	12175
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 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 12175

LOE ID:	24843
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 5.5 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 Upper Canyon, 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:	24992
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 this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Two samples had dissolved aluminum concentrations 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 aluminum 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 Upper Canyon, 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:	24993
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 this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. The concentrations of total aluminum in two samples were 528 and 228 ug/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 aluminum 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 Upper Canyon, 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	12211
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 antimony in 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 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 antimony in inland saline waters. The marine-estuarine sediment criterion was not exceeded; however, 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 inland saline waters, and the marine-estuarine sediment criterion was not exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12211

LOE ID:	24851
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 0.5 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 Upper Canyon, 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:	24994
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 this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. The concentrations of total antimony in two samples were 0.5 and 0.5 ug/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no applicable state or federal saltwater aquatic life standards or criteria for total antimony 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 Upper Canyon, 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:	24995
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 this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. The concentrations of dissolved antimony in two samples were 0.6 and 0.55 ug/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 dissolved antimony 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 Upper Canyon, 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	12926
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 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 12926

LOE ID:	25005
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 this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Two samples had total arsenic concentrations of 231 and 173 ug/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 arsenic 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 Upper Canyon, 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:	24855
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 7.2 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 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 Upper Canyon, 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:	25007
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 this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Two samples had dissolved arsenic concentations of 226 and 166 ug/L.
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 toxicity limit of 69 ug/L and a chronic toxicity limit 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
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at Upper Canyon, 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	12011
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 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 12011

LOE ID:	24853
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 700 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 Upper Canyon, 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	12177
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 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 12177

LOE ID:	24997
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 this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. One of two samples for total beryllium 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 applicable state or federal saltwater aquatic life standards or criteria for total beryllium 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 Upper Canyon, 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:	24996
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 this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Two dissolved berylliium samples both had concentrations 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 beryllium 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 Upper Canyon, 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:	24857
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 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 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 Upper Canyon, 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	12068
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 rwo 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 12068

LOE ID:	25183
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. Two samples had bicarbonate concentrations of 694 and 610 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 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 Upper Canyon, 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	12013
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 12013

LOE ID:	24858
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 Upper Canyon, 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	12986
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.. 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 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 12986

LOE ID:	25221
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. Two samples had dissolved boron concentrations of 9470 and 7910 ug/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 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 Upper Canyon, 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. Boron in this watershed comes from natural sources and has accumulated to high concentrations through evapoconcentration in a closed basin over geologic time. 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	12213
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 cadmium in inland saline waters. The California Toxics Rule saltwater standards and a 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 inland saline waters. The CTR standards and the sediment criterion, based on marine/estuarine toxicity, were not exceeded 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 saltwater standards and criterion based on marine/estuarine organisms were not exceeded.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12213

LOE ID:	25008
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 this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Two samples had dissolved cadmium concentrations of 0.1 and 0.8 ug/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	The California Toxics Rule's saltwater aquatic life standards for dissolved cadmium are an acute toxicity limit of 69 ug/L and a chronic toxicity limit 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
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at Upper Canyon, 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:	25009
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 this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. The concentrations of total cadmium in two samples were 0.11 and 0.11 ug/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 cadmium in 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 Upper Canyon, 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:	24888
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 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 cadmium in sediment in inland saline waters. The Probable Effects Level for cadmium in marine and estuarine sediments is 4.21 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 Upper Canyon, 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	12928
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 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 3.2 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 12928

LOE ID:	25584
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 15, 2005 under the Region 6 SWAMP program. The concentration of caffeine in one sample was 0.0143 ug/L..
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal water quality standards or criteria for caffeine 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 Upper Canyon, was sampled.
Temporal Representation:	One 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	12179
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 12179

LOE ID:	24844
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 2.8 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 Upper Canyon, 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:	25165
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. Two samples had total calcium concentrations of 43.4 and 41.2 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 total calcium 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 Upper Canyon, 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:	25163
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. Two samples had dissolved calcium concentrations of 35.1 and 46.5 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 dissolved calcium 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 Upper Canyon, 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	12064
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 12064

LOE ID:	24850
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 0.63 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 Upper Canyon, 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	12065
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 12065

LOE ID:	24849
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 0.71 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 Upper Canyon, 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	12066
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 12066

LOE ID:	25185
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 organic carbon in one sample was 0.08 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 Upper Canyon, 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	12070
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 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 12070

LOE ID:	25184
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. Two samples had carbonate concentrations of 24 and 48 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 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 Upper Canyon, 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	12930
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 12930

LOE ID:	24859
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 81 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 Upper Canyon, 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	12067
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 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 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 12067

LOE ID:	25170
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. Two samples had dissolved chloride concentrations of 422 and 295 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 dissolved 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 Upper Canyon, 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	12215
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. Thred 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 (CTR) standard and a sediment criterion were not exceeded. These 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 CTR saltwater standards and sediment criterion were not exceeded and this does not exceed the allowable frequency in Table 3.1 of the listing policy. However, 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 saltwater 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 12215

LOE ID:	25010
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. One of two samples for total chromium was below the detection level and the concentration in the other was 0.0 ug/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 chromium 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 Upper Canyon, 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:	25011
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 for dissolved chromium 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:	The California Toxics Rule's saltwater aquatic life standards for dissolved chromium are an acute toxicity limit of 1100 ug/L and a chronic toxicity limit of 50 ug/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 Upper Canyon, 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:	24885
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 Upper Canyon, 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	12181
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 12181

LOE ID:	25013
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 this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Two samples had total cobalt concentrations of 0.46 and 0.51 ug/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 cobalt for 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
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at Upper Canyon, 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:	25012
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 this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Two samples had dissolved cobalt concentrations of 0.15 and 0.2 ug/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no applicable state or federal saltwater aquatic life standards or criteria for cobalt for 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
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at Upper Canyon, 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:	24860
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 5 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 Upper Canyon, 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	12931
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, for total and dissolved copper in water, and copper in sediment, are available in the administrative record to assess this pollutant. None of the samples exceeds the California Toxics Rule standard or the marine/estuarine sediment criterion.. 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. Neither of two water samples nor the single sediment sample exceeded the applicable standards or 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 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 12931

LOE ID:	24886
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 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 copper in sediment in inland saline waters. The Effects Range-Median for copper in marine and estuarine sediments is 270 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 Upper Canyon, 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:	25015
Pollutant:	Copper
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. Two samples dissolved total copper concentrations of 3 and 2.8 ug/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	The California Toxics Rule's saltwater aquatic life standards for dissolved copper include 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
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at Upper Canyon, 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:	25014
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 this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Two samples had total copper concentrations of 6 and 13.2 ug/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no applicable state or federal saltwater aquatic life standards or criteria for total copper for 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
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at Upper Canyon, 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	16233
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 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 16233

LOE ID:	27057
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. Two samples had deuterium/protium ratios of -91.7 and -91.9 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 Upper Canyon, 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	12362
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 is available in the administrative record to assess this pollutant. Neither of the two of the 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 satisfy 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 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 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 12362

LOE ID:	25157
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 under the Region 6 SWAMP program. Two samples had percent saturation values of 121 and 118 percent dissolved oxygen.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	The Lahontan Basin Plan's regionwide narrative objective for dissolved oxygen provides that percent saturation shall not be depressed more than 10 percent nor shall the minimum dissolved oxygen concentration be less than 80 percent of 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 Upper Canyon, 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	12933
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 12933

LOE ID:	24861
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 Upper Canyon, 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	12987
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 is available in the administrative record to assess this pollutant. The single sample is 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. The single sample (an estimated value) does 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 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 12987

LOE ID:	25182
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:	Water column surveys (e.g. fecal coliform)
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 a 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 Upper Canyon, 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 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	12984
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.. 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12984

LOE ID:	25171
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. Two samples had dissolved fluoride concentrations of 4.4 and 3.7 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 dissolved 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 Upper Canyon, 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	12016
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:
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12016

LOE ID:	24862
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 12 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 Upper Canyon, 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	12017
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, 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 gold 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 12017

LOE ID:	24863
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 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 gold 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 Upper Canyon, 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	16213
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 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 taken.) 3. No biological data are available for assessment of compliance with the objective and the two samples 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 16213

LOE ID:	27058
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. Two samples had gross alpha radioactivity levels of 11 and 16.4 pCi/L. No biological data are available for assessment of compliance with the narrative water quality objective.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no specific state or federal saltwater aquatic life standards or criteria for gross alpha radioactivity in inland saline waters. The Lahontan Basin Plan's narrative water quality 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 extent which presents a hazard to human, plant, animal or aquatic life." The objective also incorporates California Maximum Contaminant Levels (MUN) for radioactivity for waters designated for the MUN use. The 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 Upper Canyon, 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	16139
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 water quality 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 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 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 16139

LOE ID:	25161
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 under the Region 6 SWAMP program. Two samples had hardness values of 210 and 290 ug/L CaCO3.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no state or federal saltwater aquatic life standards for hardness in inland saline waters.. Hardness is monitored for purposes such as determination of the applicable freshwater aquatic life 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).
	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 Upper Canyon, 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	12018
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 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 12018

LOE ID:	24864
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 Upper Canyon, 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	12182
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 12182

LOE ID:	25000
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 this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. One of two samples for dissolved iron was an estimated value and the iron concentration in the other was 20 ug/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 dissolved iron 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 Upper Canyon, 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:	25004
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 this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Two samples had total iron concentrations of 620 and 220 ug/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 iron 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 Upper Canyon, 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:	24865
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 2.1 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 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 Upper Canyon, 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	12936
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 12936

LOE ID:	24866
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 47 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 Upper Canyon, 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	12219
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) saltwater standards and a sediment criterion were not exceeded. Both of these 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 CTR standards and the sediment criterion, based on toxicity to marine/estuarine organisms, were not exceeded 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 saltwater 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 12219

LOE ID:	25020
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 this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. The concentrations of total lead in two samples were 0.6 and 0.41 ug/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 lead 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 Upper Canyon, 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:	24889
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 19 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 Upper Canyon, 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:	25021
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 this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. The concentrations of total lead in two samples were 0.6 and 0.41 ug/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	The California Toxics Rule saltwater aquatic life standards for lead include an acute toxicity limit of 210 ug/L and a chronic toxicity limit of 8.1 ug/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 Upper Canyon, 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	12020
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 tithium 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 12020

LOE ID:	24867
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 26 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 Upper Canyon, 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	12184
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 12184

LOE ID:	24845
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 0.76 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 Upper Canyon, 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:	25166
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 under the Region 6 SWAMP program. Two samples had dissolved magnesium concentrations of 30.6 and 41.9 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 dissolved magnesium 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 Upper Canyon, 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:	25167
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 under the Region 6 SWAMP program. Two samples had total magnesium concentrations of 39 and 35.3 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 total magnesium 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 Upper Canyon, 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	12185
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 12185

LOE ID:	25023
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 this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. The concentrations of dissolved manganee in two samples were 12.6 and 85.ug/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 dissolved manganese 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 Upper Canyon, was sampled.
Temporal Representation:	Two samples were collected on Marh 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:	24868
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 410 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 Upper Canyon, 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:	25022
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 this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. The concentrations of total manganee in two samples were 34 and 94 ug/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 manganese 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 Upper Canyon, 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	12249
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 mercury in inland saline waters. However, 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.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12249

LOE ID:	25024
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. One of two samples for dissolved mercury 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 applicable state or federal saltwater aquatic life standards or criteria for dissolved mercury 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 Upper Canyon, 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:	24891
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 0.02 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 Upper Canyon, 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:	25025
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. One of two samples for total mercury 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 standards or criteria for mercury for protection of aquatic life 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 Upper Canyon, 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	12187
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 12187

LOE ID:	25027
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 this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. The concentrations of dissolved molybdenum in two samples were 39.1 and 40.6 ug/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 dissolved molybdenum 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 Upper Canyon, 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:	24869
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 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 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 Upper Canyon, 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:	25026
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 this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. The concentrations of total molybdenum in two samples were 38.2 and 39.8 ug/L
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no applicable state or federal saltwater aquatic life standards or criteria for total molybdenum 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 Upper Canyon, 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	12932
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 12932

LOE ID:	24870
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 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 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 Upper Canyon, 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	12222
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 California Toxics Rule (CTR)saltwater standards were not exceeded; however, tthey 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 nickel samples did not exceed the CTR standards 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 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 12222

LOE ID:	25028
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 this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. The concentrations of dissolved nickel in two samples were 0.98 and 0.98 ug/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	The California Toxics Rule standards for dissolved nickel include an acute toxicity lmit of 74 ug/L and a chronic toxicity limit of 8.2 ug/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 Upper Canyon, 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:	25029
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 this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. The concentrations of total nickel in two samples were 2.05 and 2.1 ug/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no applicable state or federal saltwater aquatic life standards or criteria for total nickel 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 Upper Canyon, 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:	24883
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 nickel was 8 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 Upper Canyon, 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	12022
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 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 12022

LOE ID:	24871
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 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 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 Upper Canyon, 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	12373
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 12373

LOE ID:	25178
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 this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Two samples had nitrite plus nitrate concentrations of 0.009 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 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:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at Upper Canyon, 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	12376
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 12376

LOE ID:	25179
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 this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Two samples had nitrite concentrations of 0.001 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:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at Upper Canyon, 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	16214
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 3.1 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 objectives 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 collected.) 3. There are no applicable water quality standards or criteria and the data cannot be assessed usingTable 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 16214

LOE ID:	27059
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. Two samples had oxygen 18/oxygen 16 ratios of -11.82 and -11.98.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no specific state or federal saltwater aquatic life standards or criteria for oxygen 18/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 Upper Canyon, 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	12363
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 12363

LOE ID:	25156
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 under the Region 6 SWAMP program. The concentrations of dissolved oxygen in two samples were 10.4 and 10 mg/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	The applicable water quality objective, from Lahontan Basin Plan Table 3-16, is a one-day minimum of 5 ug/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 Upper Canyon, 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	16140
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. The single sample exceeds the water quality criterion for irrigation water. To Water Board staff's knowledge the surface waters of the Amargosa River are not used for irrigation. The definition of the Agricultural Supply beneficial use includes both irrigation and livestock watering. The extent to which livestock watering is an existing use is unknown. 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 exceeded the irrigation water criterion and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. The minimum sample number requirement of Table 3.2 was 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 16140

LOE ID:	25226
Pollutant:	Percent Sodium
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
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 15, 2005 under the Region 6 SWAMP program. Percent sodium in one sample was 81 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. Water with percent sodium greater than 70 to 75 percent is considered to be unsuitable for irrigation.
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 Upper Canyon, was sampled.
Temporal Representation:	One 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. To Lahontan Water Board staff's knowledge, the Amargosa River is not used 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	12375
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 12375

LOE ID:	25180
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 this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Two samples had dissolved phosphate concentrations of 0.255 and 0.185 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 dissolved phosphate. 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:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at Upper Canyon, 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	12378
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 water quality standards or criteria for phosphorus in sediment. No biological data are available for assessment whether any of the total phosphorus samples in water exceeds the water quality objective for biostimulatory substances. 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 satisfythe 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 for phosphorus in sediment and there are no biological data available for assessment of compliance with the wate quality objective. 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 sediment standards or criteria and 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 12378

LOE ID:	25181
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 this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Two samples had total phosphorus concentrations of 0.312 and 0.246 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 for inland surface 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:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at Upper Canyon, 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:	24848
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 0.048 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 Upper Canyon, 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	12364
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 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 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 12364

LOE ID:	25168
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 under the Region 6 SWAMP program. Two samples had dissolved potassium concentrations of 43.2 and 40.7 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 dissolved potassium 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 Upper Canyon, 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:	24846
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 2.8 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 Upper Canyon, 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	16215
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. 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. 3. No biological data are available for assessment of compliance with the water quality 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 16215

LOE ID:	27060
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. Two samples had radium 226 levels of 0.06 and 0.093 pCi/L. No biological data are available for assessment of compliance with the narrative water quality objective.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no specific state or federal saltwater aquatic life standards or criteria for radium 226 in inland saline waters. The Lahontan Basin Plan's narrative water quality 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 extent which presents a hazard to human, plant, animal or aquatic life." The objective also incorporates California Maximum Contaminant Levels (MUN) for radioactivity for waters designated for the MUN use. The 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 Upper Canyon, 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	12023
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 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 12023

LOE ID:	24872
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 Upper Canyon, 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	16217
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 16217

LOE ID:	27063
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 sampled this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Suspended sediment concentrations in two samples were 22 and 15 mg/L. One of the instantaneous flow figures was an estimate and the other was 3 cubic feet per second. One of the calculated suspended sediment loads was an estimate and the other 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 Upper Canyon, 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	12237
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 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 selenium in inland saline waters. The California Toxics Rule standards, 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 dissolved selenium samples did not exceed the California Toxics Rule standards, and this does not exceed the allowable frequency in Listing Policy Table 3.1. 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 saltwater 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 12237

LOE ID:	25030
Pollutant:	Selenium
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 for dissolved selenium was an estimated value and the concentration in the other was 1 ug/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	The California Toxics Rule standards for dissolved selenium include an acute toxicity limit of 290 ug/L and a chronic toxicity limit of 71 ug/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 Upper Canyon, 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:	25031
Pollutant:	Selenium
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 for total selenium was below the detection level and the concentration in the other was 1.4 ug/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no applicable state or federal saltwater aquatic life standards or criteria for total selenium in inland surface 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 Upper Canyon, 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:	24873
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 Upper Canyon, 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	12072
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 12072

LOE ID:	25174
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. Two samples had dissolved silica concentrations of 60.8 and 58 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 dissolved 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 Upper Canyon, 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	12228
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 saltwater standard and a sediment criterion were not exceeded. However, 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 inland saline waters. The saltwater standard and criterion, based on toxicity to marine/estuarine organisms, were not exceeded, and this does not exceed the allowable frequency in Table 3.1 of the Listing Policy. However, 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 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 12228

LOE ID:	25032
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. Concentrations of total silver 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 state or federal saltwater aquatic life standards or criteria for total silver.
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 Upper Canyon, 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:	25033
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. Concentrations of dissolved silver in two samples were both below the detection level.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	The California Toxics Rule standard for dissolved silver is an acute toxicity limit of 1.9 ug/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 Upper Canyon, 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:	24890
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 0.1 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 silver in sediment in inland saline waters. The Probable Effects Level for silver in marine and estuarine sediments is 1.77 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 Upper Canyon, 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	16141
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 aquatic life standards or criteria for sodium in the water or sediment of inland surface 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. Samples were collected only once a year. 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 standards or criteria.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 16141

LOE ID:	24847
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 1.8 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 Upper Canyon, 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:	25169
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 under the Region 6 SWAMP program. Two samples had dissolved sodium concentrations of 878 and 660 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 dissolved sodium 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 Upper Canyon, 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	12073
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 that are not designated for the MUN beneficial use. 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 12073

LOE ID:	25160
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 under the Region 6 SWAMP program. Specific conductance values in two measurements were 3820 and 3260 microsiemens per centimeter (uS/cm)..
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 specific conductance 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 Upper Canyon, was sampled.
Temporal Representation:	Two measurements of specific conductance 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	12934
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 12934

LOE ID:	24874
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 370 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 Upper Canyon, 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	12081
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 12081

LOE ID:	25175
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. Two samples had dissolved sulfate concentrations of 690 and 680 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 dissolved 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 Upper Canyon, 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	12063
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 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 12063

LOE ID:	25186
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 in one sample was 0.08 percent dry weight.
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 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 Upper Canyon, 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	12935
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 12935

LOE ID:	24875
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 Upper Canyon, 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	13166
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 13166

LOE ID:	25159
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 under the Region 6 SWAMP program. Temperatures in two measurements were 20 and 20.5 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 Upper Canyon, was sampled.
Temporal Representation:	Two temperature measurements 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	12188
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 12188

LOE ID:	24998
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. Two samples for total thallium 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 total thallium 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 Upper Canyon, 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:	24876
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 Upper Canyon, 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:	24999
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. Two samples for dissolved thallium 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 thallium 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 Upper Canyon, 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	12027
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 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:
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 12027

LOE ID:	24877
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 14 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 Upper Canyon, 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	12025
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 12025

LOE ID:	24878
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 Upper Canyon, 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	12029
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 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 12029

LOE ID:	24879
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 0.34 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 Upper Canyon, 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	12080
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 expressed as TDS and one sample expressed as "Residue", is available in the administrative record to assess this pollutant. 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 12080

LOE ID:	25176
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. Two samples had TDS concentrations of 2640 and 2210 mg/L. Another sample was reported as "residue" (the sum of constituents); itsconcentration was 2180 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 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 Upper Canyon, was sampled.
Temporal Representation:	Three 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	16138
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:	Pollution
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 the chemical data exceed the water quality objective for biostimulatory substances. 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 16138

LOE ID:	25177
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 this station on March 17, 2004 and March 15, 2005 under the Region 6 SWAMP program. Two samples had TKN concentrations of 0.63 and 0.36 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:	2007. Water Quality Control Plan for the Lahontan Region (as amended).
Evaluation Guideline:
Guideline Reference:
Spatial Representation:	One station, Amargosa River at Upper Canyon, 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	16206
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 shows detectable triclopyr and therefore 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. The single sample exceeded the water quality objective and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. The minimum sample number requirements of Table 3.1 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 the minimum sample number requirement of the Listing Policy is not met.
SWRCB Board Decision / Staff Recommendation:
USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 16206

LOE ID:	27049
Pollutant:	Triclopyr
LOE Subgroup:	Pollutant-Water
Matrix:	Water
Fraction:	None
Beneficial Use:	Inland Saline Water Habitat
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 under the Region 6 SWAMP program. The single sample had a detectable triclopyr concentration of 0.07 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 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 Upper Canyon, 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	16216
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 line of evidence is available in the administrative record to assess this pollutant. No biological data are available for assessment whether either of the samples exceeds the narrative 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 to evaluate 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 16216

LOE ID:	27062
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. Two samples had tritium levels of 0.8 and 1.1 pCi/L. The tritium 2 sigma combined uncertainties were 0.58 and 0.58 pCi/L. No biological data are available for assessment of compliance with the narrative water quality objective.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no specific state or federal saltwater aquatic life standards or criteria for tritium in inland saline waters. The Lahontan Basin Plan's narrative water quality 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 extent which presents a hazard to human, plant, animal or aquatic life." The objective also incorporates California Maximum Contaminant Levels (MUN) for radioactivity for waters designated for the MUN use. The 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 Upper Canyon, 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	16142
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 an antidegradation-based objective and the two available samples are insufficient to document baseline and trend conditions as required under Listing Policy Section 3.10. Both samples are reported as NTU but one may actually be for NTRU. If this is the case the two samples are not 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. (Samples were collected only once a year.) 3. The requirements of Listing Policy section 3.10 to document baseline and trend conditions are not met in relation to the narrative water quality objective. 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 16142

LOE ID:	25155
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. Turbidity values in one measurement was 12 NTU. (Note: a second turbidity measurement from 2005 was reported as NTU but includes the method number associated with NTRU in data for a different Amargosa River station.)
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	The regionwide turbidity objective in the Lahontan Basin Plan 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 Upper Canyon, was sampled.
Temporal Representation:	One turbidity measurement expressed as NTU 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:	27155
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. Turbidity in one measurement was reported as 6.4 NTU. The USGS has recently begun measuring turbidity as NTRU, using equipment different than that used for NTU. The 2005 measurement has the same method number as a March 2005 NTRU measurement for a different Amargosa River station and should probably be interpreted as NTRU.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	The regionwide turbidity objective in the Lahontan Basin Plan 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 Upper Canyon, was sampled.
Temporal Representation:	One turbidity measurement expressed as NTU (but probably for NTRU) 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	13200
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.` 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 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 (only one sample) 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 13200

LOE ID:	24884
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 2.6 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 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 Upper Canyon, 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	12189
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 12189

LOE ID:	25006
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. Two samples had total vanadium concentrations of 10 and 6 ug/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 vanadium 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 Upper Canyon, 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:	24880
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 51 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 Upper Canyon, 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:	25040
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. Two samples had dissolved vanadium concentrations of 13.2 and 14.2 ug/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no applicable state or federal saltwater aquatic life standards or criteria for dissolved vanadium 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 Upper Canyon, 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	12028
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 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 12028

LOE ID:	24881
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 Upper Canyon, 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	12030
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 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 12030

LOE ID:	24882
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 18 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 Upper Canyon, 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	12246
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 Toxic Rule standards and a 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 zinc in inland saline waters. The California Toxics Rule standards and sediment criterion were not exceeded and this does not exceed the allowable frequency in Listing Policy Table 3.1. However, 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 water, and the saltwater 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 12246

LOE ID:	25042
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 2 samples were both estimated values.
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 zinc in inland surface 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 Upper Canyon, 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:	24887
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 Upper Canyon, 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:	25041
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. Two samples had dissolved zinc concentrations of 1.8 and 2.2 ug/L.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	The California Toxics Rule standards for dissolved zinc include an acute toxicity limit of 90 ug/L and a chronic toxicity limit of 81 ug/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 Upper Canyon, 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	13180
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 13180

LOE ID:	25158
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 under the Region 6 SWAMP program. In two measurements, pH was 8.6 and 8.7 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 Upper Canyon, was sampled.
Temporal Representation:	Two pH measurements 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	16228
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	Original
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. 3. There are no biological data available for assessment of compliance with the narrative water quality 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 16228

LOE ID:	27141
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. Two samples had gross beta radioactivity levels of 41 and 63 pCi/L. No biological data are available for assessment of compliance with the narrative water quality objective.
Data Reference:	2007. SWAMP Data for the Amargosa Hydrologic Unit.
Water Quality Objective/Criterion:	There are no specific state or federal saltwater aquatic life standards or criteria for gross beta radioactivity in inland saline waters. The Lahontan Basin Plan's narrative water quality 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 extent which presents a hazard to human, plant, animal or aquatic life." The objective also incorporates California Maximum Contaminant Levels (MUN) for radioactivity for waters designated for the MUN use. The 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 Upper Canyon, 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):