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

Supporting Information

Regional Board 6 - Lahontan Region

Water Body Name: Susan River (Susanville to Litchfield)
Water Body ID: CAR6372005020080815013207
Water Body Type: River & Stream
 
DECISION ID
16200
 
Pollutant: Mercury
Final Listing Decision: Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: Natural Sources
Expected TMDL Completion Date: 2019
Impairment from Pollutant or Pollution: Pollutant
 
Weight of Evidence: The State Water Board listed the Susan River as a whole for mercury during the 2006 assessment cycle on the basis of trout tissue samples that exceeded OEHHA fish consumption criteria. The trout were collected at stations above and below Susanville. The river was divided into three segments for the 2008 assessment cycle, and this decision documents continued listing for the middle segment. There is no known fish passage barrier between the two segments.

This pollutant is being considered for removal from the section 303(d) list under section 4.5 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status.

One line of evidence is available in the administrative record to assess pollutant. Two samples exceed the OEHHA tissue criterion.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the section 303(d) list.

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 satisfy the data quantity requirements of section 6.1.5 of the Policy.
3. Two of 4 samples exceeded the tissue criterion however this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are being met.
4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.
 
RWQCB Board Decision / Staff Recommendation: This is a decision made by the State Water Resources Control Board and approved by the USEPA in 2006 . No new data were assessed by the Regional Board for 2008. The decision has not changed.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 16200
 
LOE ID: 6688
 
Pollutant: Mercury
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Total
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
Number of Samples: 4
Number of Exceedances: 2
 
Data and Information Type: Fish tissue analysis
Data Used to Assess Water Quality: Two out of 4 samples exceeded. Four filet composite samples, two each, of rainbow trout and brook trout were collected. Rainbow trout were collected in 1998-99. Brook trout were collected in 1999 and 2001. The 1999 rainbow and brook trout samples exceeded the guideline. Both sampled stations exceeded the guideline in 1999 (TSMP, 2002).
Data Reference: Placeholder reference 2006 303(d)
 
Water Quality Objective/Criterion: Lahontan RWQCB Basin Plan: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or produce detrimental physiological responses in human, plant, animal, or aquatic life.
Objective/Criterion Reference: Placeholder reference 2006 303(d)
 
Evaluation Guideline: OEHHA Screening Value 0.3 μg/g (Brodberg & Pollock, 1999).
Guideline Reference: Placeholder reference 2006 303(d)
 
Spatial Representation: Two stations were sampled: just upstream of HWY 36 bridge on the Susan River (Susanville) and downstream of Piute Creek mouth at Alexander Street bridge (Piute Creek).
Temporal Representation: Samples were collected annually in 1998-99 and 2001.
Environmental Conditions:
QAPP Information: Environmental Chemistry Quality Assurance and Data Report for the Toxic Substances Monitoring Program, 1996-2000. Department of Fish and Game.
Environmental Chemistry Quality Assurance and Data Report for the Toxic Substances Monitoring Program, 2001-2002. Department of Fish and Game.
QAPP Information Reference(s):
 
DECISION ID
16201
 
Pollutant: Unknown Toxicity
Final Listing Decision: Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: Source Unknown
Expected TMDL Completion Date: 2019
Impairment from Pollutant or Pollution: Pollutant
 
Weight of Evidence: This pollutant is being considered for removal from the section 303(d) list under section 4.6 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status.

One line of evidence is available in the administrative record to assess pollutant. Eleven of the samples exceed the water quality objective.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the section 303(d) list.

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 satisfy the data quantity requirements of section 6.1.5 of the Policy.
3. Eleven of 36 samples exceeded the water quality objective and this exceeds the allowable frequency listed in Table 4.1 of the Listing Policy.
4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are 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 removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 16201
 
LOE ID: 27172
 
Pollutant: Unknown Toxicity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 36
Number of Exceedances: 11
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: The U.C. Davis Aquatic Toxicology Laboratory sampled the Susan River monthly between May 2003 and August 2004 and tested each sample with three different organisms. Eleven of 36 samples for Stations SR2, SR3 and SR4 showed at least one toxic response.
Data Reference: 2005. Susan River Toxicity Testing Project, Final Report May 2003-August 2004. University of California Davis Aquatic Toxicity Laboratory. Contract # 02-107-250-0 with Lahontan RWQCB and SWRCB.
 
Water Quality Objective/Criterion: The Lahontan Basin Plan's narrative water quality objective for Toxicty provides that: "All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrmental physiological responses in human, plant, animal or aquatic life."
Objective/Criterion Reference: 2007. Water Quality Control Plan for the Lahontan Region (as amended).
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Three stations in this segment were sampled: SR2, Susan River at McGowan Lane; SR3, Susan River at Leavitt Road bridge, and SR4, Susan River upstream of Litchfield at Bridge 7-34 on Highway 395.
Temporal Representation: Twelve monthly samples were collected at each station between May 2003 and August 2004.
Environmental Conditions: The Susan River is an internally drained river in eastern Lassen County with its headwaters near Lassen Volcanic National Park and its terminus in Honey Lake in the Great Basin. The Susan River is designated for both the Warm Freshwater Habitat and Cold Freshwater Habitat beneficial uses, and for the Spawning, Reproduction and Development and Migration of Aquatic Organisms uses.
QAPP Information: The UC Davis Aquatic Toxicology Laboratory prepared a QAPP for the study that was acceptable to RWQCB staff. Quality Assurance procedures are summarized in the contract report.
QAPP Information Reference(s):
 
DECISION ID
8117
 
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.

Two lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:
1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy.
2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the seasonal and annual variability expected in streamflows and constituent concentrations in streams of the Lahontan Region.
3. None of five annual average datapoints exceeded the site-specific objective. None of 16 samples exceeded the Maximum Contaminant Level and this does not exceed the allowable frequency listed in 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 applicable water quality standards are not being exceeded.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 8117
 
LOE ID: 6925
 
Pollutant: Chloride
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 5
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 the Susan River under the Region 6 SWAMP program between 2001 and 2005. Chloride concentrations in 16 quarterly samples (3-4 per year) ranged from 1.92 to 8.96 mg/L. Annual average concentrations ranged from 5.82 to 7.87 mg/L. The annual average objective was not exceeded.during any of the five years of sampling.
Data Reference: 2007. SWAMP Data for the Susan River.
 
Water Quality Objective/Criterion: The site-specific objective from Lahontan Basin Plan Table 3-9 is an annual average chloride concentration of 8 mg/L.
Objective/Criterion Reference: 2007. Water Quality Control Plan for the Lahontan Region (as amended).
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: One station (Susan River near Litchfield) was sampled.
Temporal Representation: Sixteen quarterly samples (3 to 4 per year) were collected between 2001 and 2005.
Environmental Conditions: The Susan River is an internally drained river in eastern Lassen County with its headwaters near Lassen Volcanic National Park and its terminus in Honey Lake in the Great Basin. Water quality in the lower reach is affected by geothermal springs, agricultural diversions and agricultural drainage. pH in the lower reach is affected by alkaline desert soils. The Susan River is designated for both the Warm Freshwater Habitat and Cold Freshwater Habitat beneficial uses, and for the Spawning, Reproduction and Development and Migration of Aquatic Organisms uses.
QAPP Information: The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
 
LOE ID: 6926
 
Pollutant: Chloride
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 16
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 the Susan River under the Region 6 SWAMP program between 2001 and 2005. Chloride concentrations in 16 quarterly samples (3-4 per year) ranged from 1.92 to 8.96 mg/L. The MCL was not exceeded.
Data Reference: 2007. SWAMP Data for the Susan River.
 
Water Quality Objective/Criterion: California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for chloride is 250 mg/L.
Objective/Criterion Reference: 2007. Water Quality Control Plan for the Lahontan Region (as amended).
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: One station (Susan River near Litchfield) was sampled.
Temporal Representation: Sixteen quarterly samples (3 to 4 per year) were collected between 2001 and 2005.
Environmental Conditions: The Susan River is an internally drained river in eastern Lassen County with its headwaters near Lassen Volcanic National Park and its terminus in Honey Lake in the Great Basin. Water quality in the lower reach is affected by geothermal springs, agricultural diversions and agricultural drainage. pH in the lower reach is affected by alkaline desert soils. The Susan River is designated for both the Warm Freshwater Habitat and Cold Freshwater Habitat beneficial uses, and for the Spawning, Reproduction and Development and Migration of Aquatic Organisms uses.
QAPP Information: The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
 
DECISION ID
8118
 
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. None of the samples exceed the water quality objective.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:
1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy.
2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy.
3. None of three samples exceeded the water quality objective and this does not exceed the allowable frequency listed in 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 8118
 
LOE ID: 6930
 
Pollutant: Dissolved oxygen saturation
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 3
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 the Susan River under the Region 6 SWAMP program between 2001 and 2005. Three measurements of dissolved oxygen saturation ranged from 112 to 178 percent. The objective was not exceeded.
Data Reference: 2007. SWAMP Data for the Susan River.
 
Water Quality Objective/Criterion: The Lahontan Basin Plan's narrative objective states that percent saturation shall not be depressed by more than 10 percent and minimum dissolved oxygen concentration shall not be less than 80 percent saturation.
Objective/Criterion Reference: 2007. Water Quality Control Plan for the Lahontan Region (as amended).
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: One station (Susan River near Litchfield) was sampled.
Temporal Representation: Three measurements of percent saturation of dissolved oxygen were taken on October 20,2004, January 25, 2005 and July 20, 2005.
Environmental Conditions: The Susan River is an internally drained river in eastern Lassen County with its headwaters near Lassen Volcanic National Park and its terminus in Honey Lake in the Great Basin. Water quality in the lower reach is affected by geothermal springs, agricultural diversions and agricultural drainage. The highest temperatures in the SWAMP samples were measured during the summer low flow season. The Susan River is designated for both the Warm Freshwater Habitat and Cold Freshwater Habitat beneficial uses. It is also designated for the Spawning, Reproduction and Development and the Migration of Aquatic Organisms uses.
QAPP Information: The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
 
DECISION ID
8119
 
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.

Two line of evidence are available in the administrative record to assess this pollutant. Four of the samples exceed the water quality objective.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:
1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy.
2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the seasonal and annual variability expected in streamflows and fecal coliform counts in streams of the Lahontan Region. The water quality objective calls for five samples to be collected within a 30-day period.
3. Four of eight samples exceeded the water quality objective and this does not exceed the allowable frequency listed in 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 applicable water quality standards are not being exceeded.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 8119
 
LOE ID: 6924
 
Pollutant: Fecal Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 8
Number of Exceedances: 4
 
Data and Information Type: Water column surveys (e.g. fecal coliform)
Data Used to Assess Water Quality: The U.S. Geological Survey sampled the Susan River under the Region 6 SWAMP program between. Eight quarterly samples for fecal coliform bacteria were collected between September 2003 and July 2005. Three samples were estimated values and one was below the detection level. Fecal coliform bacteria counts in the remaining four samples ranged from 48 to 170 colonies per 100 mL, all above the limit in the objective The objective was not violated.
Data Reference: 2007. SWAMP Data for the Susan River.
 
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 waste.

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 a 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 (Susan River near Litchfield) was sampled.
Temporal Representation: Eight quarterly samples were collected between September 2003 and July 2005.
Environmental Conditions: The Susan River is an internally drained river in eastern Lassen County with its headwaters near Lassen Volcanic National Park and its terminus in Honey Lake in the Great Basin. Water quality in the lower reach is affected by geothermal springs, agricultural diversions and agricultural drainage. pH in the lower reach is affected by alkaline desert soils. The Susan River is designated for both the Warm Freshwater Habitat and Cold Freshwater Habitat beneficial uses, and for the Spawning, Reproduction and Development and Migration of Aquatic Organisms uses.
QAPP Information: The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
 
LOE ID: 6923
 
Pollutant: Fecal Coliform
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 8
Number of Exceedances: 4
 
Data and Information Type: Water column surveys (e.g. fecal coliform)
Data Used to Assess Water Quality: The U.S. Geological Survey sampled the Susan River under the Region 6 SWAMP program between. Eight quarterly samples for fecal coliform bacteria were collected between September 2003 and July 2005. Three samples were estimated values and one was below the detection level. Fecal coliform bacteria counts in the remaining four samples ranged from 48 to 170 colonies per 100 mL, all above the limit in the objective The objective was not violated.
Data Reference: 2007. SWAMP Data for the Susan River.
 
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 waste.

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 a 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 (Susan River near Litchfield) was sampled.
Temporal Representation: Eight quarterly samples were collected between September 2003 and July 2005.
Environmental Conditions: The Susan River is an internally drained river in eastern Lassen County with its headwaters near Lassen Volcanic National Park and its terminus in Honey Lake in the Great Basin. Water quality in the lower reach is affected by geothermal springs, agricultural diversions and agricultural drainage. pH in the lower reach is affected by alkaline desert soils. The Susan River is designated for both the Warm Freshwater Habitat and Cold Freshwater Habitat beneficial uses, and for the Spawning, Reproduction and Development and Migration of Aquatic Organisms uses.
QAPP Information: The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
 
DECISION ID
15417
 
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. None 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 satsify the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the seasonal and annual variability expected in streamflows and constituent concentrations in streams of the Lahontan Region.
3. None of 16 samples exceeded the water quality objective and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
RWQCB Board Decision / Staff Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 15417
 
LOE ID: 23472
 
Pollutant: Nitrate/Nitrite (Nitrite + Nitrate as N)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 16
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 the Susan River under the Region 6 SWAMP program between 2001 and 2005. Concentrations of nitrite plus nitrate in seven of16 quarterly samples were below the detection level. Concentrations in the remaining samples ranged from 0.001 to 0.112 mg/L. The MCL was not exceeded.
Data Reference: 2007. SWAMP Data for the Susan River.
 
Water Quality Objective/Criterion: California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for nitrite plus nitrate is mg/L.
Objective/Criterion Reference: 2007. Water Quality Control Plan for the Lahontan Region (as amended).
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: One station (Susan River near Litchfield) was sampled.
Temporal Representation: Sixteen quarterly samples (3 to 4 per year) were collected between 2001 and 2005.
Environmental Conditions: The Susan River is an internally drained river in eastern Lassen County with its headwaters near Lassen Volcanic National Park and its terminus in Honey Lake in the Great Basin. Water quality in the lower reach is affected by geothermal springs, agricultural diversions and agricultural drainage. pH in the lower reach is affected by alkaline desert soils. The Susan River is designated for both the Warm Freshwater Habitat and Cold Freshwater Habitat beneficial uses, and for the Spawning, Reproduction and Development and Migration of Aquatic Organisms uses.
QAPP Information: The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
 
DECISION ID
8120
 
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. One 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 dsatisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the diel, seasonal and annual variability expected in streamflows and dissolved oxygen concentrations in streams of the Lahontan Region.
3. One of 13 samples exceeded the water quality objective and this does not exceed the allowable frequency listed in 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 applicable water quality standards are not being exceeded.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 8120
 
LOE ID: 6929
 
Pollutant: Oxygen, Dissolved
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 13
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 the Susan River under the Region 6 SWAMP program between 2001 and 2005. Concentrations of dissolved oxygen in 13 quarterly samples ranged from 6.6 to 15.2 mg/L. One of 13 samples was below 8 mg/L.
Data Reference: 2007. SWAMP Data for the Susan River.
 
Water Quality Objective/Criterion: The water quality objective, from Lahontan Basin Plan Table 3-6, is a one -day minimum dissolved oxygen concentration of 8 mg/L.
Objective/Criterion Reference: 2007. Water Quality Control Plan for the Lahontan Region (as amended).
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: One station (Susan River near Litchfield) was sampled.
Temporal Representation: Thirteen (approximately) quarterly samples (2 to 3 per year) were taken between 2001 and 2005.
Environmental Conditions: The Susan River is an internally drained river in eastern Lassen County with its headwaters near Lassen Volcanic National Park and its terminus in Honey Lake in the Great Basin. Water quality in the lower reach is affected by geothermal springs, agricultural diversions and agricultural drainage. The highest temperatures in the SWAMP samples were measured during the summer low flow season. The Susan River is designated for both the Warm Freshwater Habitat and Cold Freshwater Habitat beneficial uses. It is also designated for the Spawning, Reproduction and Development and the Migration of Aquatic Organisms uses.
QAPP Information: The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
 
DECISION ID
8122
 
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. There was insufficient information to determine whether the single sample 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 single sample used does not satisfy the data quantity requirements of section 6.1.5 of the Policy.
3. It could not be determined whether the single sample exceeded the objective and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
RWQCB Board Decision / Staff Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because 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 8122
 
LOE ID: 6933
 
Pollutant: Phosphate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater 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 the Susan River under the Region 6 SWAMP program. A single sample collected March 23, 2004 was analyzed for dissolved PO4-P. The concentration was 0.038 mg/L.
Data Reference: 2007. SWAMP Data for the Susan River.
 
Water Quality Objective/Criterion: There is no site-specific objective for phosphate applicable to this station. (Compliance with the site-specific objective for Total Phosphorus has been assessed separately.) The Lahontan Basin Plan's narrative 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 (Susan River near Litchfield) was sampled.
Temporal Representation: One sample was collected on March 23, 2004.
Environmental Conditions: The Susan River is an internally drained river in eastern Lassen County with its headwaters near Lassen Volcanic National Park and its terminus in Honey Lake in the Great Basin. Water quality in the lower reach is affected by geothermal springs, agricultural diversions and agricultural drainage. The Susan River is designated for both the Warm Freshwater Habitat and Cold Freshwater Habitat beneficial uses, and for the Spawning, Reproduction and Development and Migration of Aquatic Organisms uses.
QAPP Information: The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
 
DECISION ID
8123
 
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.

One line of evidence is available in the administrative record to assess this pollutant. None of five annual average datapoints exceed the water quality objective.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:
1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy.
2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the seasonal and annual variability expected in streamflows and constituent concentrations in streams of the Lahontan Region.
3. None of five annual average datapoints exceeded the site-specific water quality objective and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
RWQCB Board Decision / Staff Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 8123
 
LOE ID: 6932
 
Pollutant: Phosphorus
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 5
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 the Susan River under the Region 6 SWAMP program between 2001 and 2005. Concentrations of total phosphorus in 4 of 16 quarterly samples were estimated values. Concentrations in the remaining samples ranged from 0.06 to 0.191 mg/L. The annual average objective was not exceeded.during any of the five years of sampling.
Data Reference: 2007. SWAMP Data for the Susan River.
 
Water Quality Objective/Criterion: The water quality objective for this station in Lahontan Basin Plan Table 3-9 includes an annual average Total Phosphorus concentration of 0.25 mg/L and a 90th percentile value of 0.30 mg/L.
Objective/Criterion Reference: 2007. Water Quality Control Plan for the Lahontan Region (as amended).
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: One station (Susan River near Litchfield) was sampled.
Temporal Representation: Sixteen quarterly samples (3 to 4 per year) were collected between 2001 and 2005.
Environmental Conditions: The Susan River is an internally drained river in eastern Lassen County with its headwaters near Lassen Volcanic National Park and its terminus in Honey Lake in the Great Basin. Water quality in the lower reach is affected by geothermal springs, agricultural diversions and agricultural drainage. The Susan River is designated for both the Warm Freshwater Habitat and Cold Freshwater Habitat beneficial uses, and for the Spawning, Reproduction and Development and Migration of Aquatic Organisms uses.
QAPP Information: The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
 
DECISION ID
15419
 
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 quarterly sampling, is available in the administrative record to assess this pollutant.

Suspended sediment concentrations and loads are dependent on flows and can change rapidly over a short time during storm or snowmelt runoff events. Quarterly 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.The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the seasonal and annual variability expected in streamflows and constituent concentrations in streams of the Lahontan Region.
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 15419
 
LOE ID: 23474
 
Pollutant: Sediment
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 11
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 the Susan River under the Region 6 SWAMP program between 2002 and 2005. Concentrations of suspended sediment in 11 samples ranged from 9 to 91 mg/L. Sediment loads were calculated for 7 sampling dates between 2003 and 2005; loads ranged from 0.35 to 62 tons per day. (Instantaneous discharge flows used in the load calculations ranged from 7.2 to 253 cubic feet per second.)
Data Reference: 2007. SWAMP Data for the Susan River.
 
Water Quality Objective/Criterion: The narrative objective for suspended sediment in the Lahontan Basin Plan 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 (Susan River near Litchfield) was sampled.
Temporal Representation: Eleven samples (2 to 4 per year) were taken between 2002 and 2005.
Environmental Conditions: The Susan River is an internally drained river in eastern Lassen County with its headwaters near Lassen Volcanic National Park and its terminus in Honey Lake in the Great Basin. Water quality in the lower reach is affected by geothermal springs, agricultural diversions and agricultural drainage. The highest temperatures in the SWAMP samples were measured during the summer low flow season. The Susan River is designated for both the Warm Freshwater Habitat and Cold Freshwater Habitat beneficial uses. It is also designated for the Spawning, Reproduction and Development and the Migration of Aquatic Organisms uses.
QAPP Information: The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
 
DECISION ID
8121
 
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 is available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:
1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy.
2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the seasonal and annual variability expected in streamflows and dissolved ion concentrations in streams of the Lahontan Region.
3. None of 16 samples exceeded the Maximum Contaminant Level and this does not exceed the allowable frequency listed in 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 applicable water quality standards are not being exceeded.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 8121
 
LOE ID: 6928
 
Pollutant: Specific Conductance
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 16
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 the Susan River under the Region 6 SWAMP program between 2001 and 2005. Specific conductance in 16 quarterly field measurements (3-4 per year) ranged from 133 to 545 uS/cm. Two additional laboratory measurements were taken in samples collected on the field sampling dates. Laboratory specific conductances ere 398 and 388 uS/cm. The MCL was not exceeded.
Data Reference: 2007. SWAMP Data for the Susan River.
 
Water Quality Objective/Criterion: California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for specific conductance is 900 microsiemens per centimeter (uS/cm).
Objective/Criterion Reference: 2007. Water Quality Control Plan for the Lahontan Region (as amended).
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: One station (Susan River near Litchfield) was sampled.
Temporal Representation: Sixteen quarterly field measurements (3 to 4 per year) were taken between 2001 and 2005. Two additional laboratory measurements were taken on samples collected on the field sampling dates.
Environmental Conditions: The Susan River is an internally drained river in eastern Lassen County with its headwaters near Lassen Volcanic National Park and its terminus in Honey Lake in the Great Basin. Water quality in the lower reach is affected by geothermal springs, agricultural diversions and agricultural drainage. The Susan River is designated for both the Warm Freshwater Habitat and Cold Freshwater Habitat beneficial uses, and for the Spawning, Reproduction and Development and Migration of Aquatic Organisms uses.
QAPP Information: The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
 
DECISION ID
15420
 
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 Cold Freshwater Habitat (COLD) beneficial use. The objective does not include specific numerical limits for protection of the COLD 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 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.

Because temperature samples were collected only quarterly, weekly and monthly average data are not available for comparison with guidelines in the scientific literature for the temperature requirements of sensitive aquatic species such as salmonids, as directed in Listing Policy Section 6.1.5.9.
 
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 15420
 
LOE ID: 6927
 
Pollutant: Temperature, water
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 16
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 the Susan River under the Region 6 SWAMP program between 2001 and 2005. Water temperatures in 16 quarterly samples at ranged from 3 to 29.5 degrees Celsius.
Data Reference: 2007. SWAMP Data for the Susan River.
 
Water Quality Objective/Criterion: The applicable language from the Lahontan Basin Plan's temperature objective is as follows: "The natural receiving water temperature of al l waters shall not be altered unless it can be demonstrated to the satisfaction fo 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."
Objective/Criterion Reference: 2007. Water Quality Control Plan for the Lahontan Region (as amended).
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: One station (Susan River near Litchfield) was sampled.
Temporal Representation: Sixteen quarterly measurements of water temperature (3 to 4 per year) were taken between 2001 and 2005.
Environmental Conditions: The Susan River is an internally drained river in eastern Lassen County with its headwaters near Lassen Volcanic National Park and its terminus in Honey Lake in the Great Basin. Water quality in the lower reach is affected by geothermal springs, agricultural diversions and agricultural drainage. The highest temperatures in the SWAMP samples were measured during the summer low flow season. The Susan River is designated for both the Warm Freshwater Habitat and Cold Freshwater Habitat beneficial uses. It is also designated for the Spawning, Reproduction and Development and the Migration of Aquatic Organisms uses.
QAPP Information: The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
 
DECISION ID
15425
 
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.

Two lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceeds the California Maximum Contaminant Level (MCL). Five out of 5 annual average datapoints (based on only 3 to 4 samples per year) exceed the site-specific water quality objective. However, listing is not recommended because the data are not temporally representative.

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. Quarterly samples do not capture the full range of seasonal and annual variability in streamflows and constituent concentrations expected in streams of the Lahontan Region.
3. None of 16 samples exceeded the MCL and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. Five out of five annual average datapoints exceeded the site-specific 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, although one of the applicable water quality standards is being exceeded, the data are not temporally representative.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 15425
 
LOE ID: 6935
 
Pollutant: Total Dissolved Solids
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 5
Number of Exceedances: 5
 
Data and Information Type: Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: The U.S. Geological Survey sampled the Susan River under the Region 6 SWAMP program between 2001 and 2005. TDS concentrations in 16 quarterly samples ranged from 103 to 361 mg/L. Annual average TDS concentrations (calculated from 3-4 samples per year) ranged from 227 to 253 mg/L. The annual average objective was exceeded in 5 of 5 years.
Data Reference: 2007. SWAMP Data for the Susan River.
 
Water Quality Objective/Criterion: The site-specific objective for Total Dissolved Solids (TDS) includes an annual average of 185 mg/L and a 250 mg/L 90th percentile value (Lahontan Basin Plan Table 3-9).
Objective/Criterion Reference: 2007. Water Quality Control Plan for the Lahontan Region (as amended).
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: One station (Susan River near Litchfield) was sampled.
Temporal Representation: Sixteen quarterly samples (3 to 4 per year) were collected between 2001 and 2005.
Environmental Conditions: The Susan River is an internally drained river in eastern Lassen County with its headwaters near Lassen Volcanic National Park and its terminus in Honey Lake in the Great Basin. Water quality in the lower reach is affected by geothermal springs, agricultural diversions and agricultural drainage. The Susan River is designated for both the Warm Freshwater Habitat and Cold Freshwater Habitat beneficial uses, and for the Spawning, Reproduction and Development and Migration of Aquatic Organisms uses.
QAPP Information: The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
 
LOE ID: 6934
 
Pollutant: Total Dissolved Solids
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 16
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 the Susan River under the Region 6 SWAMP program between 2001 and 2005. TDS concentrations in 16 quarterly samples (3-4 per year) ranged from 103 to 361 mg/L. The MCL was not exceeded.
Data Reference: 2007. SWAMP Data for the Susan River.
 
Water Quality Objective/Criterion: California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for Total Dissolved Solids (TDS) is 500 mg/L.
Objective/Criterion Reference: 2007. Water Quality Control Plan for the Lahontan Region (as amended).
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: One station (Susan River near Lichfield) was sampled.
Temporal Representation: Sixteen quarterly samples (3 to 4 per year) were collected between 2001 and 2005.
Environmental Conditions: The Susan River is an internally drained river in eastern Lassen County with its headwaters near Lassen Volcanic National Park and its terminus in Honey Lake in the Great Basin. Water quality in the lower reach is affected by geothermal springs, agricultural diversions and agricultural drainage. pH in the lower reach is affected by alkaline desert soils. The Susan River is designated for both the Warm Freshwater Habitat and Cold Freshwater Habitat beneficial uses, and for the Spawning, Reproduction and Development and Migration of Aquatic Organisms uses.
QAPP Information: The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
 
DECISION ID
15421
 
Pollutant: Total Kjeldahl Nitrogen (TKN)
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Weight of Evidence: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

One line of evidence are available in the administrative record to assess this pollutant. No biological data are available to determine 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 satisfiy 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. Quarterly samples do not capture the seasonal and annual variability expected in streamflows and constituent concentrations in streams of the Lahontan Region.
3. No biological data are available for assessment of compliance with the water quality objective for biostimuatory substances.
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 15421
 
LOE ID: 23471
 
Pollutant: Total Kjeldahl Nitrogen (TKN)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 16
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 the Susan River under the Region 6 SWAMP program between 2001 and 2005. . Concentrations of TKN in 16 quarterly samples ranged from 0.22 to 0.69 mg/L.
Data Reference: 2007. SWAMP Data for the Susan River.
 
Water Quality Objective/Criterion: The Lahontan Basin Plan does not include a site-specific objective (SSO) for total Kjeldahl nitrogen (TKN) in the Susan River. The narrative 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 (Susan River near Litchfield) was sampled.
Temporal Representation: Sixteen quarterly samples were collected between 2001 and 2005.
Environmental Conditions: The Susan River is an internally drained river in eastern Lassen County with its headwaters near Lassen Volcanic National Park and its terminus in Honey Lake in the Great Basin. Water quality in the lower reach is affected by geothermal springs, agricultural diversions and agricultural drainage. The Susan River is designated for both the Warm Freshwater Habitat and Cold Freshwater Habitat beneficial uses, and for the Spawning, Reproduction and Development and Migration of Aquatic Organisms uses.
QAPP Information: The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
 
DECISION ID
15424
 
Pollutant: Total Nitrogen 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. One of the annual average datapoints 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. Quarterly samples do not capture the seasonal and annual variability expected in streamflows and constituent concentrations in streams of the Lahontan Region.
3. One of five annual average datapoints samples exceeded the water quality objective and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
RWQCB Board Decision / Staff Recommendation: After review of the available data and information, RWQCB staff concludes that though this water body is impaired for sediment toxicity, these water body-pollutant combinations should not be placed on the section 303(d) list because applicable water quality standards for these pollutants are not being exceeded
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 15424
 
LOE ID: 23473
 
Pollutant: Total Nitrogen as N
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 5
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 the Susan River under the Region 6 SWAMP program between 2001 and 2005. Calculated concentrations of total nitrogen ranged from 0.25 to 0.801 mg/L. Annual average concentrations were estimates in 3 of 5 years; the remaining averages were 0.486 and 0.660 mg/L. The site-specific objective was exceeded in 1 of 5 years.
Data Reference: 2007. SWAMP Data for the Susan River.
 
Water Quality Objective/Criterion: The water quality objective for this station in Lahontan Basin Plan Table 3-9 includes an annual average total nitrogen concentration of 0.65 mg/L and a 90th percentile value of 0.80 mg/L.
Objective/Criterion Reference: 2007. Water Quality Control Plan for the Lahontan Region (as amended).
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: One station (Susan River near Litchfield) was sampled.
Temporal Representation: Sixteen quarterly samples each were collected for total Kjeldahl nitrogen and nitrite plus nitrate between 2001 and 2005. Total nitrogen was calculated for 16 sampling dates.
Environmental Conditions: The Susan River is an internally drained river in eastern Lassen County with its headwaters near Lassen Volcanic National Park and its terminus in Honey Lake in the Great Basin. Water quality in the lower reach is affected by geothermal springs, agricultural diversions and agricultural drainage. The Susan River is designated for both the Warm Freshwater Habitat and Cold Freshwater Habitat beneficial uses, and for the Spawning, Reproduction and Development and Migration of Aquatic Organisms uses.
QAPP Information: The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
 
DECISION ID
15426
 
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: This pollutant is being considered for placement on the section 303(d) list under sections 3.2 and 3.10 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status.

Four lines of evidence are available in the administrative record to assess this pollutant. There are no applicable standards for turbidity expressed as NTRU. The Lahontan Basin Plan's narrative water quality objective for turbidity expressed as NTU is antidegradation based, and the available data are insufficient to determine baseline-trend conditions pursuant to Section 3.10 of the Policy. Ten of the samples expressed as NTU exceed the California Maximum Contaminant Level (MCL). However, listing is not being recommended because the data are not temporally representative.

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. Quarterly samples do not capture the full range of diel, seasonal and annual varibility expected in streamflows and turbidity levels in streams of the Lahontan Region.
3. Ten of 12 samples exceeded the MCL and this exceeds the allowable frequency listed in 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, although one of the applicable water quality standards is being exceeded, the data are not temporally representative.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 15426
 
LOE ID: 23475
 
Pollutant: Turbidity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 12
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 the Susan River under the Region 6 SWAMP program between 2001 and 2004. Turbidity in 12 measurements reported as NTU ranged from 0.6 to 33 NTU.
Data Reference: 2007. SWAMP Data for the Susan River.
 
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 (Susan River near Litchfield) was sampled.
Temporal Representation: Twelve quarterly turbidity measurements reported as NTU were taken between 2001 and 2005.
Environmental Conditions: The Susan River is an internally drained river in eastern Lassen County with its headwaters near Lassen Volcanic National Park and its terminus in Honey Lake in the Great Basin. Water quality in the lower reach is affected by geothermal springs, agricultural diversions and agricultural drainage. The Susan River is designated for both the Warm Freshwater Habitat and Cold Freshwater Habitat beneficial uses, and for the Spawning, Reproduction and Development and Migration of Aquatic Organisms uses.
QAPP Information: The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
 
LOE ID: 23477
 
Pollutant: Turbidity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 12
Number of Exceedances: 10
 
Data and Information Type: Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: The U.S. Geological Survey sampled the Susan River under the Region 6 SWAMP program between 2001 and 2004. Turbidity in 12 measurements reported as NTU ranged from 0.6 to 33 NTU. Ten of 12 samples exceeded the MCL.
Data Reference: 2007. SWAMP Data for the Susan River.
 
Water Quality Objective/Criterion: California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for turbidity is 5 NTU.
Objective/Criterion Reference: 2007. Water Quality Control Plan for the Lahontan Region (as amended).
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: One station (Susan River near Litchfield) was sampled.
Temporal Representation: Twelve quarterly turbidity measurements reported as NTU were taken between 2001 and 2005.
Environmental Conditions: The Susan River is an internally drained river in eastern Lassen County with its headwaters near Lassen Volcanic National Park and its terminus in Honey Lake in the Great Basin. Water quality in the lower reach is affected by geothermal springs, agricultural diversions and agricultural drainage. The Susan River is designated for both the Warm Freshwater Habitat and Cold Freshwater Habitat beneficial uses, and for the Spawning, Reproduction and Development and Migration of Aquatic Organisms uses.
QAPP Information: The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
 
LOE ID: 23478
 
Pollutant: Turbidity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 4
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 the Susan River under the Region 6 SWAMP program between 2004 and 2005. Turbidity in 4 measurements reported as NTRU ranged from 6 to 32 NTRU.
Data Reference: 2007. SWAMP Data for the Susan River.
 
Water Quality Objective/Criterion: There are no state or federal standards or criteria for turbidity expressed as NTRU for the protection of human health.
Objective/Criterion Reference: 2007. Water Quality Control Plan for the Lahontan Region (as amended).
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: One station (Susan River near Litchfield) was sampled.
Temporal Representation: Four quarterly turbidity measurements reported as NTRU were taken between 2004 and 2005.
Environmental Conditions: The Susan River is an internally drained river in eastern Lassen County with its headwaters near Lassen Volcanic National Park and its terminus in Honey Lake in the Great Basin. Water quality in the lower reach is affected by geothermal springs, agricultural diversions and agricultural drainage. The Susan River is designated for both the Warm Freshwater Habitat and Cold Freshwater Habitat beneficial uses, and for the Spawning, Reproduction and Development and Migration of Aquatic Organisms uses.
QAPP Information: The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
 
LOE ID: 23476
 
Pollutant: Turbidity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 4
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 the Susan River under the Region 6 SWAMP program between 2004 and 2005. Turbidity in 4 measurements reported as NTRU ranged from 6 to 32 NTRU.
Data Reference: 2007. SWAMP Data for the Susan River.
 
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 (Susan River near Litchfield) was sampled.
Temporal Representation: Four quarterly turbidity measurements reported as NTRU were taken between 2004 and 2005.
Environmental Conditions: The Susan River is an internally drained river in eastern Lassen County with its headwaters near Lassen Volcanic National Park and its terminus in Honey Lake in the Great Basin. Water quality in the lower reach is affected by geothermal springs, agricultural diversions and agricultural drainage. The Susan River is designated for both the Warm Freshwater Habitat and Cold Freshwater Habitat beneficial uses, and for the Spawning, Reproduction and Development and Migration of Aquatic Organisms uses.
QAPP Information: The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
 
DECISION ID
15422
 
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 beneficial uses. 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 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 15422
 
LOE ID: 6931
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 16
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 the Susan River under the Region 6 SWAMP program between 2001 and 2005. The pH of 16 quarterly measurements ranged from 6.6 to 9.7 units. One additional laboratory measurement had a pH of 8.3 units.
Data Reference: 2007. SWAMP Data for the Susan River.
 
Water Quality Objective/Criterion: The water quality objective in the Lahontan Basin Plan 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 (Susan River near Litchfield) was sampled.
Temporal Representation: Sixteen quarterly field measurements of pH (3 to 4 per year) were taken between 2001 and 2005. One additional laboratory measurement was done on a sample collected in September 2003.
Environmental Conditions: The Susan River is an internally drained river in eastern Lassen County with its headwaters near Lassen Volcanic National Park and its terminus in Honey Lake in the Great Basin. Water quality in the lower reach is affected by geothermal springs, agricultural diversions and agricultural drainage. The highest temperatures in the SWAMP samples were measured during the summer low flow season. The Susan River is designated for both the Warm Freshwater Habitat and Cold Freshwater Habitat beneficial uses. It is also designated for the Spawning, Reproduction and Development and the Migration of Aquatic Organisms uses.
QAPP Information: The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):