Draft California 2018 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 6 - Lahontan Region

Water Body Name:	Stony Creek (Lassen County)
Water Body ID:	CAR6374008020080811110419
Water Body Type:	River & Stream


DECISION ID	73876	Region 6
Stony Creek (Lassen County)

Pollutant:	Indicator Bacteria
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Staff Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: 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 lines of evidence are 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 do not 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 or Table 3.2 of the Policy. 3. One of 4 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.

Regional Board Staff Decision Recommendation:	This region was not assessed this cycle. All decisions have been carried over from the previous cycle and remain the same.

Line of Evidence (LOE) for Decision ID 73876, Indicator Bacteria	Region 6
Stony Creek (Lassen County)

LOE ID:

25902

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

Water column surveys (e.g. fecal coliform)

Data Used to Assess Water Quality:

The U.S. Bureau of Land Management sampled four different stations in Stony Creek on four dates in July and August 2002. Fecal coliform counts in 4 samples anged from 8 to 21 colonies per 100 mL. One sample exceeded the 20 colonies per 100 mL limit. (Because the objective requires a minimum of five samples in a 30 day period, log means were not calculated.)

Data Reference:

Water quality data for surface waters on U.S Bureau of Land Management lands in Lassen and Modoc Counties

SWAMP Data:

Non-SWAMP

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:

Water Quality Control Plan for the Lahontan Region (as amended)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Four different stations (Numbers ST1-Alt, ST-2, ST-3 and ST-4) were sampled.

Temporal Representation:

The four stations were sampled on July 2, August 13, August 14, and August 23, 2002.

Environmental Conditions:

Stony Creek is a tributary of Secret Creek in the Snowstorm Mountain Hydrologic Area of Lassen County.(The spelling ¿Stoney¿ is used in the USBLM database; however the creek is ¿Stony¿ on topographic maps.) In addition to the Cold Freshwater Habitat beneficial use, Stony Creek is designated for the Spawning, Reproduction and Development use. No site-specific water quality objectives have been established for the waters of this watershed.

QAPP Information:

No quality assurance informaiton was submitted with the data.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 73876, Indicator Bacteria	Region 6
Stony Creek (Lassen County)

LOE ID:

25901

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

Water column surveys (e.g. fecal coliform)

Data Used to Assess Water Quality:

Data Reference:

Water quality data for surface waters on U.S Bureau of Land Management lands in Lassen and Modoc Counties

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Lahontan Region (as amended)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Four different stations (Numbers ST1-Alt, ST-2, ST-3 and ST-4) were sampled.

Temporal Representation:

The four stations were sampled on July 2, August 13, August 14, and August 23, 2002.

Environmental Conditions:

QAPP Information:

No quality assurance informaiton was submitted with the data.

QAPP Information Reference(s):


DECISION ID	74991	Region 6
Stony Creek (Lassen County)

Pollutant:	Nitrogen, Nitrate
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Staff Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: 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. None of the samples exceeds the California Maximum Contaminant Level (MCL). No biological data are available for assessment of compliance with 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 do not 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 4 samples exceeded the MCL and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. No biological data are available for assessment of compliance with the objective for biostimulatory substances. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Staff Decision Recommendation:	This region was not assessed this cycle. All decisions have been carried over from the previous cycle and remain the same.

Line of Evidence (LOE) for Decision ID 74991, Nitrogen, Nitrate	Region 6
Stony Creek (Lassen County)

LOE ID:

25898

Pollutant:

Nitrate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

The U.S. Bureau of Land Management sampled four different stations in Stony Creek on four dates in July and August 2002. Concentrations of NO3-N in four samples ranged from 0.12 to 0.16 mg/L. The MCL was not violated.

Data Reference:

Water quality data for surface waters on U.S Bureau of Land Management lands in Lassen and Modoc Counties

SWAMP Data:

Non-SWAMP

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 nitrate is 45 mg/L expressed "as nitrate," equivalent to 10 mg/L expressed "as N."

Objective/Criterion Reference:

Water Quality Control Plan for the Lahontan Region (as amended)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Four different stations (Numbers ST1-Alt, ST-2, ST-3 and ST-4) were sampled.

Temporal Representation:

The four stations were sampled on July 2, August 13, August 14, and August 23, 2002.

Environmental Conditions:

QAPP Information:

No quality assurance informaiton was submitted with the data.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 74991, Nitrogen, Nitrate	Region 6
Stony Creek (Lassen County)

LOE ID:

25896

Pollutant:

Nitrate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

The U.S. Bureau of Land Management sampled four different stations in Stony Creek on four dates in July and August 2002. Concentrations of NO3-N in four samples ranged from 0.12 to 0.16 mg/L.

Data Reference:

Water quality data for surface waters on U.S Bureau of Land Management lands in Lassen and Modoc Counties

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Lahontan Basin Plan does not include site specific objectives for this water body. The regionwide 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:

Water Quality Control Plan for the Lahontan Region (as amended)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Four different stations (Numbers ST1-Alt, ST-2, ST-3 and ST-4) were sampled.

Temporal Representation:

The four stations were sampled on July 2, August 13, August 14, and August 23, 2002.

Environmental Conditions:

QAPP Information:

No quality assurance informaiton was submitted with the data.

QAPP Information Reference(s):


DECISION ID	73553	Region 6
Stony Creek (Lassen County)

Pollutant:	Specific Conductivity
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Staff Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: 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 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 do not 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 or Table 3.2 of the Policy. 3. None of 4 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.

Regional Board Staff Decision Recommendation:	This region was not assessed this cycle. All decisions have been carried over from the previous cycle and remain the same.

Line of Evidence (LOE) for Decision ID 73553, Specific Conductivity	Region 6
Stony Creek (Lassen County)

LOE ID:

25893

Pollutant:

Specific Conductance

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

The U.S. Bureau of Land Management sampled four different stations in Stony Creek on four dates in July and August 2002. Specific conductance in four samples ranged from 228 to 298 uS/cm. The MCL was not exceeded.

Data Reference:

Water quality data for surface waters on U.S Bureau of Land Management lands in Lassen and Modoc Counties

SWAMP Data:

Non-SWAMP

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:

Water Quality Control Plan for the Lahontan Region (as amended)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Four different stations (Numbers ST1-Alt, ST-2, ST-3 and ST-4) were sampled.

Temporal Representation:

The four stations were sampled on July 2, August 13, August 14, and August 23, 2002.

Environmental Conditions:

QAPP Information:

No quality assurance informaiton was submitted with the data.

QAPP Information Reference(s):


DECISION ID	74879	Region 6
Stony Creek (Lassen County)

Pollutant:	Phosphate
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Staff Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: 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 of compliance with 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 do not satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. No biological data are available for assessment of compliance with the objective for biostimulatory substances. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Staff Decision Recommendation:	This region was not assessed this cycle. All decisions have been carried over from the previous cycle and remain the same.

Line of Evidence (LOE) for Decision ID 74879, Phosphate	Region 6
Stony Creek (Lassen County)

LOE ID:

25897

Pollutant:

Phosphate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

The U.S. Bureau of Land Management sampled four different stations in Stony Creek on four dates in July and August 2002. Concentrations of PO4-P in four samples ranged from 0.33 to 0.46 mg/L.

Data Reference:

Water quality data for surface waters on U.S Bureau of Land Management lands in Lassen and Modoc Counties

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Lahontan Region (as amended)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Four different stations (Numbers ST1-Alt, ST-2, ST-3 and ST-4) were sampled.

Temporal Representation:

The four stations were sampled on July 2, August 13, August 14, and August 23, 2002.

Environmental Conditions:

QAPP Information:

No quality assurance informaiton was submitted with the data.

QAPP Information Reference(s):


DECISION ID	74086	Region 6
Stony Creek (Lassen County)

Pollutant:	Temperature, water
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Staff Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: One line of evidence is available in the administrative record to assess this pollutant. The water quality objective for temperature is antidegradation based. The four available samples cannot be used to document baseline and trend conditions to assess compliance with the objective using Listing Policy section 3.10. 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 do not satisfy the data quality requirements of section 6.1.4 of the Policy (both samples were collected within one month.. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. The four available samples are insufficient to assess compliance with the objective under section 3.10 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Staff Decision Recommendation:	This region was not assessed this cycle. All decisions have been carried over from the previous cycle and remain the same.

Line of Evidence (LOE) for Decision ID 74086, Temperature, water	Region 6
Stony Creek (Lassen County)

LOE ID:

25895

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

The U.S. Bureau of Land Management sampled four different stations in Stony Creek on four dates in July and August 2002. Water temperature in 4 samples ranged from 13 to 16 degrees Celsius.

Data Reference:

Water quality data for surface waters on U.S Bureau of Land Management lands in Lassen and Modoc Counties

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The relevant sections of the Lahontan Basin Plan's temperature objective are as follows: "The natural receiving water temperature of all 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:

Water Quality Control Plan for the Lahontan Region (as amended)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Four different stations (Numbers ST1-Alt, ST-2, ST-3 and ST-4) were sampled.

Temporal Representation:

The four stations were sampled on July 2, August 13, August 14, and August 23, 2002.

Environmental Conditions:

QAPP Information:

No quality assurance informaiton was submitted with the data.

QAPP Information Reference(s):


DECISION ID	80254	Region 6
Stony Creek (Lassen County)

Pollutant:	Turbidity
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Staff Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: 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. Two of four samples exceed the California Maximum Contaminant Level. The narrative water quality objective for turbidity is antidegradation based, and the available data are insufficient for assessment of compliance under Section 3.10 of the Listing Policy. 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 do not 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 or Table 3.2 of the Policy. 3. Two of 4 samples exceeded the Maximum Contaminant Level and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. The data are insufficient to assess compliance with the narrative turbidity objective under section 3.10 of the policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Staff Decision Recommendation:	This region was not assessed this cycle. All decisions have been carried over from the previous cycle and remain the same.

Line of Evidence (LOE) for Decision ID 80254, Turbidity	Region 6
Stony Creek (Lassen County)

LOE ID:

25900

Pollutant:

Turbidity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

The U.S. Bureau of Land Management sampled four different stations in Stony Creek on four dates in July and August 2002. Turbidity in four measurements ranged from 1.4 to 8.1 NTU. Two samples exceeded the MCL.

Data Reference:

Water quality data for surface waters on U.S Bureau of Land Management lands in Lassen and Modoc Counties

SWAMP Data:

Non-SWAMP

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:

Water Quality Control Plan for the Lahontan Region (as amended)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Four different stations (Numbers ST1-Alt, ST-2, ST-3 and ST-4) were sampled.

Temporal Representation:

The four stations were sampled on July 2, August 13, August 14, and August 23, 2002.

Environmental Conditions:

QAPP Information:

No quality assurance informaiton was submitted with the data.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 80254, Turbidity	Region 6
Stony Creek (Lassen County)

LOE ID:

25899

Pollutant:

Turbidity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

The U.S. Bureau of Land Management sampled four different stations in Stony Creek on four dates in July and August 2002. Turbidity in four measurements ranged from 1.4 to 8.1 NTU.

Data Reference:

Water quality data for surface waters on U.S Bureau of Land Management lands in Lassen and Modoc Counties

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Lahontan Basin Plan's regionwide turbidity objective states: "Waters shall be free of changes in turbidity that cause nuisance or adversely affect the water for beneficial uses. Increases in turbidity shall not exceed natural levels by more than 10 percent."

Objective/Criterion Reference:

Water Quality Control Plan for the Lahontan Region (as amended)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Four different stations (Numbers ST1-Alt, ST-2, ST-3 and ST-4) were sampled.

Temporal Representation:

The four stations were sampled on July 2, August 13, August 14, and August 23, 2002.

Environmental Conditions:

QAPP Information:

No quality assurance informaiton was submitted with the data.

QAPP Information Reference(s):


DECISION ID	74135	Region 6
Stony Creek (Lassen County)

Pollutant:	pH
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Staff Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: One line of evidence is available in the administrative record to assess this pollutant. The water quality objective for pH is antidegradation based. The 4 available samples cannot be used to document baseline and trend conditions to assess compliance with the objective using Listing Policy section 3.10. 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 do not satisfy the data quality requirements of section 6.1.4 of the Policy (both samples were collected within one month). 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. The 4 available samples are insufficient to assess compliance with the objective under section 3.10 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Staff Decision Recommendation:	This region was not assessed this cycle. All decisions have been carried over from the previous cycle and remain the same.

Line of Evidence (LOE) for Decision ID 74135, pH	Region 6
Stony Creek (Lassen County)

LOE ID:

25894

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

The U.S. Bureau of Land Management sampled four different stations in Stony Creek on four dates in July and August 2002. The pH in four samples ranged from 7.35 to 7.7 units.

Data Reference:

Water quality data for surface waters on U.S Bureau of Land Management lands in Lassen and Modoc Counties

SWAMP Data:

Non-SWAMP

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:

Water Quality Control Plan for the Lahontan Region (as amended)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Four different stations (Numbers ST1-Alt, ST-2, ST-3 and ST-4) were sampled.

Temporal Representation:

The four stations were sampled on July 2, August 13, August 14, and August 23, 2002.

Environmental Conditions:

QAPP Information:

No quality assurance informaiton was submitted with the data.

QAPP Information Reference(s):