Final California 2010 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 6 - Lahontan Region

Water Body Name:	Mesquite Springs (Inyo County)
Water Body ID:	CAW6091100020080825153033
Water Body Type:	Wetland, Freshwater


DECISION ID	7767	Region 6
Mesquite Springs (Inyo County)

Pollutant:	Alkalinity as CaCO3
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	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 criterion. However, only two samples were available and this does not meet the minimum sample number requirement of Listing Policy Table 3.2. 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. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 7767, Alkalinity as CaCO3	Region 6
Mesquite Springs (Inyo County)

LOE ID:

6042

Pollutant:

Alkalinity as CaCO3

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. Two samples were taken for alkalinity. One result was an estimated 326 mg/L and the other was 353 mg/L. The chronic criterion was not exceeded.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The USEPA's national water quality criteria recommend a minimum hardness of 20 mg/L calcium carbonate as a chronic criterion for the protection of aquatic life, unless the natural alkalinity level is lower.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	7616	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	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 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 in that only one sample per year is available. 3. Neither of two samples exceeded the applicable water quality objective and aquatic life criterion, and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 7616, Aluminum	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5744

Pollutant:

Aluminum

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. Two samples for dissolved aluminum were both estimated values. The USEPA aquatic life criterion was not exceeded.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The U.S. Environmental Protection Agency (USEPA) 4-day average freshwater aquatic life criterion for aluminum is 87 ug/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 7616, Aluminum	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5484

Pollutant:

Aluminum

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The primary MCL for aluminum is 1000 ug/L, and the secondary MCL is 200 ug/L. Concentrations of dissolved aluminum in two samples were both estimates. The MCLs were not exceeded.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	7686	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 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 applicable standard and criteria. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. Neither of two samples exceeded the applicable objective and criteria 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 Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 7686, Antimony	Region 6
Mesquite Springs (Inyo County)

LOE ID:

6041

Pollutant:

Antimony

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. Dissolved antimony concentrations in two samples were 1.1 and 0.92 ug/L. The USEPA aquatic life criteria were not exceeded.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The U.S. Environmental Protection Agency's (USEPA's) Lowest Observed Effect Levels (LOELs) criteria are as follows: Acute toxicity = 9000 ug/L; Chronic toxicity = 1600 ug/L. The USEPA criterion for toxicity to algae = 610 ug/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 7686, Antimony	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5315

Pollutant:

Antimony

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. Dissolved antimony concentrations in two samples were 1.1 and 0.92 ug/L.The MCL was not exceeded. (Note: MCLs for metals are expressed as total rather than dissolved.)

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

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 antimony is 6 ug/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	7618	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	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 satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. Neither of two 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.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 7618, Barium	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5272

Pollutant:

Barium

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Dissolved barium concentrations in two samples were 22 and 23 ug/L. The MCL was not exceeded

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The California MCL for barium is 1000 ug/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	10685	Region 6
Mesquite Springs (Inyo County)

Pollutant:	Beryllium \| Iron \| Lead \| Silver \| Thallium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	These pollutants are being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess these pollutants. None of the samples for any of the pollutants exceeds the applicable water quality criteria, California Toxics Rule standards, or California Maximum Contaminant Levels. All metals concentrations were at nondetectable levels. Under Listing Policy 6.1.5.5, the standards and criteria are presumed to be attained. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. None of the two samples for each pollutant exceeded the applicable standard or criterion and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision 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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 10685, Multiple Pollutants	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5792

Pollutant:

Beryllium | Iron | Lead | Silver | Thallium

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Sampling results for the metals above were below detection levels. Per listing policy Section 6.1.5.5 the standards and criteria are resumed to be attained.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The applicable U.S. Environmental Protection Agency freshwater aquatic life criteria are as follows. For beryllium, the acute criterion is 130 ug/L and the chronic criterion is 5.3 ug/L. For iron, the 4- day average criterion is 1000 ug/L. For thallium, the acute Lowest Observed Effect Level (LOEL) criterion is 1400 ug/L, and the chronic LOEL criterion is 40 ug/L. (An "Other" criterion for thallium is 20 ug/L.) The California Toxics Rule (CTR) aquatic life standards for lead and silver are dependent on hardness. At the reported hardness values (123 and 126 mg/L CaCO3) the CTR standards are as follows. For lead, the acute standards are 84.05 and 86.67 ug/L. The chronic standards are 3.28 and 3..38 ug/L. For silver, the standard is 4.93 and 4.13 ug/L.

Objective/Criterion Reference:

Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency

Quality Criteria for Water 1986. United States Environmental Protection Agency. Office of Water. Regulations and Standards. Washington D.C. EPA 440/5-86-001.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected for each metal in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 10685, Multiple Pollutants	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5275

Pollutant:

Beryllium | Iron | Lead | Silver | Thallium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCLs for the listed pollutants are as follows: beryllium, 4 ug/L; iron, 300 ug/L; lead, 15 ug/L; silver, 100 ug/L; thallium, 2 ug/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected for each metal in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	7609	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	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. Neither of the samples exceeds the water quality objective.or California Toxics Rule standards. 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 in that only one sample per year is available. 3. Neither of two samples exceeded the applicable standards 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.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 7609, Cadmium	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5308

Pollutant:

Cadmium

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Dissolved cadmium concentrations in two samples were 0.4 and 0.5 ug/L. The California Toxics Rule standards were not exceeded.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Toxics Rule cadmium standard for protection of freshwater aquatic life is hardness-based.
At the recorded hardness levels, the acute toxicity standard ranges from 5.39 to 5.53 ug/L The chronic toxicity standard ranges from 2.63 to 2.6 ug/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 7609, Cadmium	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5741

Pollutant:

Cadmium

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Dissolved cadmium concentrations in two samples were 0.4 and 0.5 ug/L. The MCL was not exceeded. (Note: MCLs for metals are expressed as total rather than dissolved, but total cadmium data were not available.)

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

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 cadmium is 5 ug/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	10760	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	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 of evidence are available in the administrative record to assess this pollutant. There are no California or federal standards or water quality criteria for calcium. 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 satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable standards or criteria and the data cannot be assessed pursuant to 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 Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 10760, Calcium	Region 6
Mesquite Springs (Inyo County)

LOE ID:

21250

Pollutant:

Calcium

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The concentrations of dissolved calcium in two samples were 26.2 and 27.1 mg/L.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There are no state or federal standards, water quality objectives or criteria for calcium.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	10733	Region 6
Mesquite Springs (Inyo County)

Pollutant:	Carbon 13/Carbon 12 ratio
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. There are no California or federal criteria, standards, or water quality objectives applicable to carbon 13/carbon 12 ratio. 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.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 10733, Carbon 13/Carbon 12 ratio	Region 6
Mesquite Springs (Inyo County)

LOE ID:

21276

Pollutant:

Carbon 13/Carbon 12 ratio

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The reported carbon 13/carbon 12 ratios in two samples (as ml) were -6.15 and -6.19.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There are no state or federal standards, water quality objectives or criteria for carbon 13/carbon 12 ratio.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	10728	Region 6
Mesquite Springs (Inyo County)

Pollutant:	Carbon 14
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

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. There are no state or federal water quality standards or criteria for Carson 14, and no biological data are available for assessment of compliance with the narrative water quality objective for radioactivity. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Only one sample per year is available. 3. No biological data are available for assessment of compliance with the narrative water quality objective.. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 10728, Carbon 14	Region 6
Mesquite Springs (Inyo County)

LOE ID:

21275

Pollutant:

Carbon 14

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. Carbon 14 levels in two samples were 55.43 and 55.05 percent. The count errors (as a percentage) for these samples were 0.42 and 0.45 percent. No biological data are available for evaluation of bioaccumulation or effects on beneficial uses.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There are no specific state or federal standards, water quality objectives or criteria for carbon 14. .The Lahontan Basin Plan's narrative water quality objective for "Radioactivity" states: "Radionuclides shall not be present in cocentrations which are deleterious to human, plant ,animal, or aquatic life nor which result in the accumulation of radionuclides in the food web to an extent which presents a hazard to human, plant or aquatic life." The objective also incorporates California Maximum Contaminant Level drinking water standards for radioactive constituents as water quality objectives for waters designated for the Municipal and Domestic Supply beneficial use.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	7620	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	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. Neither of the samples exceeds the applicable criterion and 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 in that only one sample per year is available. 3. Neither of two samples exceeded the applicable standards. However, the minimum sample number requirements of Table 3.2 of the Listing Policy were not met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 7620, Chloride	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5745

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Chloride concentrations in two samples were 84.6 and 82.6 mg/L. The USEPA criterion was not exceeded, but sample numbers were too small for use with the Listing Policy's binomial model.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The U.S. Environmental Protection Agency's (USEPA's) 4 day average freshwater aquatic life criterion is 230 mg/L

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 7620, Chloride	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5234

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Chloride concentrations in two samples were 84.6 and 82.6 mg/L. The MCL was not exceeded, but sample numbers were too small for use with the Listing Policy's binomial model.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

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 chloride is 250 mg/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	7610	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	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 exceed the applicable water quality objectives. 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 in that only one sample per year is available. 3. None of two samples exceeded the applicable objectives 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.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 7610, Chromium (total)	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5309

Pollutant:

Chromium (total)

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Dissolved chromium concentrations in two samples were 0.8 and 1 ug/L. The MCL was not exceeded. (The SWAMP data do not distinguish between hexavalent and trivalent chromium. MCLs for metals are expressed as total rather than dissolved, but only dissolved chromium data are available for this station.)

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The California MCL for chromium is 50 ug/L (as total chromium)..

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 7610, Chromium (total)	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5310

Pollutant:

Chromium (total)

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Dissolved chromium concentrations in two samples were 0.8 and 10 ug/L. The CTR standards were not exceeded. (The SWAMP data do not distinguish between trivalent and hexavalent chromium. Only data for dissolved chromium were available.)

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Toxics Rule (CTR) standard for Chromium III, for protection of freshwater aquatic life, is dependent on hardness. At the hardness levels reported for this station the acute toxicity standard ranges from 650.12 to 663.08 ug/L. The chronic toxicity standard ranges from 210.89 to 215.10 ug/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	7768	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. There are no California or federal criteria, standards, or water quality objectives applicable to cobalt. 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.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 7768, Cobalt	Region 6
Mesquite Springs (Inyo County)

LOE ID:

6040

Pollutant:

Cobalt

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The concentrations of dissolved cobalt in two samples were 0.053 and 0.06 ug/L.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There are no state or federal standards, water quality objectives or criteria for cobalt.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 7768, Cobalt	Region 6
Mesquite Springs (Inyo County)

LOE ID:

6043

Pollutant:

Cobalt

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The concentrations of dissolved cobalt in two samples were 0.053 and 0.06 ug/L.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There are no state or federal standards, water quality objectives or criteria for cobalt.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	7615	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	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. Neither of the samples exceeds the applicable standards. 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 in that only one sample per year is available. 3. Neither of two samples exceeded the applicable water quality standards 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.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 7615, Copper	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5743

Pollutant:

Copper

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. Dissolved copper concentrations in two samples were 0.9 and 0.7 ug/L. The California Toxics Rule standards were not exceeded.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Toxics Rule copper standard for protection of freshwater aquatic life is dependent on hardness. At the reported hardness levels, the acute toxicity standard ranges from 16.33 to 16.71 ug/L. The chronic toxicity standard ranges from 10.69 to 10.91 ug/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 7615, Copper	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5311

Pollutant:

Copper

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. Dissolved copper concentrations in two samples were 0.9 and 0.7 ug/L. The MCLs were not exceeded. (Note: MCLs for metals are expressed as total rather than dissolved.)

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The primary MCL for copper is 1300 ug/L; the secondary MCL is 1000 ug/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	10732	Region 6
Mesquite Springs (Inyo County)

Pollutant:	Deuterium/Protium ratio
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. There are no California or federal criteria, standards, or water quality objectives applicable to deuterium/protium ratio. 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.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 10732, Deuterium/Protium ratio	Region 6
Mesquite Springs (Inyo County)

LOE ID:

21283

Pollutant:

Deuterium/Protium ratio

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The reported deuterium/protium ratios in two samples (as ml) were -108 and -108.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There are no state or federal standards, water quality objectives or criteria for deuterium/protium ratio.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	7608	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	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. Neither of the samples exceeds the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. Neither of two samples exceeded the water quality objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. However, the minimum sample number requirements of Table 3.2 were not met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 7608, Fecal Coliform	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5709

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:

The U.S. Geological Survey sampled Mesquite Springs once a year in 2002 and 2003 under the Region 6 SWAMP program. Fecal coliform counts in two samples were below the detection level. Per Listing Policy Section 6.1.5.5, the objective is presumed to be attained.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

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 wastes. The fecal coliform concentration during any 30-day period shall not exceed a log mean of 20/100 ml, nor shall more than 10 percent of all samples collected during any 30-day period exceed 40/100 ml. The log mean shall ideally be based on a minimum of not less than five samples collected as evenly spaced as practicable during any 30-day period. However, a log mean concentration exceeding 20/100 ml for any 30-day period shall indicate violation of this objective even if fewer than five samples were collected."

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (Death Valley National Park), near Scottys Castle, was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 7608, Fecal Coliform	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5710

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:

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (Death Valley National Park), near Scottys Castle, was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	7621	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	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. Two 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 in that only one sample per year is available. 3. Two of two samples exceeded the California Maximum Contaminant Level and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. However, the minimum sample number requirements of the policy were not met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 7621, Fluoride	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5238

Pollutant:

Fluoride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Fluoride concentrations in two samples were 3.74 and 3.46 mg/L.. The MCL was exceeded.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

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 fluoride is 2 mg/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	10751	Region 6
Mesquite Springs (Inyo County)

Pollutant:	Hardness as CaCO3
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. There are no applicable state or federal standards or criteria for hardness. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria. 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 Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 10751, Hardness as CaCO3	Region 6
Mesquite Springs (Inyo County)

LOE ID:

21252

Pollutant:

Hardness as CaCO3

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. Two samples had calculated hardness values of 123 and 126 mg/L.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There are no state or federal standards or criteria for hardness. Hardness is monitored for purposes such as determination of the applicable criteria and standards for metals whose toxicity is hardness-dependent. The U.S. Environmental Protection Agency's 1986 "Gold Book" includes generally accepted categories of hardness. Calcium and magnesium are the major ions contributing to hardness, and hardness is generally expressed as calcium carbonate. Water with a hardness of 0 to 75 mg equivalent CaCO3/L is considered "soft."

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Hardness was calculated for two samples collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	7806	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. There are no California or federal criteria, standards, or water quality objectives applicable to lithium. 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.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 7806, Lithium	Region 6
Mesquite Springs (Inyo County)

LOE ID:

6226

Pollutant:

Lithium

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. Dissolved lithium concentrations in two samples were 219 and 186 ug/L.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There are no state or federal water quality standards or criteria for lithium.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 7806, Lithium	Region 6
Mesquite Springs (Inyo County)

LOE ID:

6225

Pollutant:

Lithium

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. Dissolved lithium concentrations in two samples were 219 and 186 ug/L.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There are no state or federal water quality standards or criteria for lithium.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	10761	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. There are no applicable California of federal water quality standards or criteria for magnesium. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable standards or criteria and the data cannot be assessed using Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 10761, Magnesium	Region 6
Mesquite Springs (Inyo County)

LOE ID:

21251

Pollutant:

Magnesium

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The concentrations of dissolved magnesium in two samples were 14.1 and 14.2 mg/L.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There are no state or federal standards, water quality objectives or criteria for magnesium.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	7617	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	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 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. Only one sample per year was taken. 3. Neither of two 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.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 7617, Manganese	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5312

Pollutant:

Manganese

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The manganese concentration in one of two samples was below detection level and the other was 0.3 ug/L. The MCL was not exceeded. (Note: MCLs for metals are expressed as total rather than dissolved.)

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

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 manganese is 50 ug/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	7687	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. There are no applicable water quality standards or criteria and the data cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 7687, Molybdenum	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5799

Pollutant:

Molybdenum

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. Dissolved molybdenum concentrations in two samples were 15.5 and 16.6 ug/L.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There are no applicable water quality standards or criteria for molybdenum for protection of the Municipal and Domestic Supply beneficial use.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	7688	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	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 or Toxics Rule standards. 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 in that only one sample per year is available. 3. Neither of two samples exceeded the applicable California Maximum Contaminant Level or California Toxics Rule standard, 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.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 7688, Nickel	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5802

Pollutant:

Nickel

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The nickel concentrations in two samples were 1.34 and 0.6 ug/L. The CTR standards for acute and chronic toxicity were not exceeded.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Toxics Rule's (CTR's) freshwater aquatic life standards for nickel are dependent on hardness. At the observed hardness values for the Mesquite Springs samples (123 and 125 mg/L CaCO3) the applicable acute toxicity standards are 557.82 and 565.52 ug/L. The applicable chronic toxicity standards are 62.022 and 62.88 ug/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 7688, Nickel	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5314

Pollutant:

Nickel

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The nickel concentrations in two samples were 1.34 and 0.6 ug/L. The MCL was not exceeded. (Note: MCLs for metals are expressed as total rather than dissolved.)

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

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 nickel is 100 ug/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	9845	Region 6
Mesquite Springs (Inyo County)

Pollutant:	Nitrate
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

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One of evidence is available in the administrative record to assess this pollutant. None of the samples exceeds the California Maximum Contaminant Level (MCL). 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 because only one sample per year is available. 3. Neither of two annual samples exceeded the MCL 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.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 9845, Nitrate	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5617

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:

Not Specified

Data Used to Assess Water Quality:

The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. The reported concentrations of nitrite in two samples were below the detection level. The reported nitrate plus nitrite concentrations in two samples were 0.205 and 0.272 mg/L. Since these are equivalent to the nitrate concentrations in the two samples, the MCL for nitrate was not violated.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

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 as nitrate, equivalent to 10 mg/L nitrate as N.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples each for nitrate plus nitrite and nitrite were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	10693	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One of evidence is available in the administrative record to assess this pollutant. Neither of the samples exceeds the California Maximum Contaminant Level (MCL). 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 in that only one sample per year is available. 3. Neither of two samples exceeded the MCL 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.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 10693, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 6
Mesquite Springs (Inyo County)

LOE ID:

21248

Pollutant:

Nitrate/Nitrite (Nitrite + Nitrate as N)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. The concentrations of nitrite plus nitrate in two samples were 0.205 and 0.272 mg/L. The MCL was not exceeded.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

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 nitrite plus nitrate is 10 mg/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	10695	Region 6
Mesquite Springs (Inyo County)

Pollutant:	Nitrite as Nitrite NO2
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

Regional Board Conclusion:	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. Neither of the samples exceeds the California Maximum Contaminant Level (MCL). 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 satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. Neither of two samples exceeded the MCL 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.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 10695, Nitrite as Nitrite NO2	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5616

Pollutant:

Nitrite as Nitrite NO2

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Nitrite concentrations in two samples were below the detection level. Per Listing Policy Section 6.1.5.5, the MCL is presumed to be attained.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

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 nitrite is 1 mg/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	10742	Region 6
Mesquite Springs (Inyo County)

Pollutant:	Oxygen 18/Oxygen 16 ratio
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. There are no California or federal criteria, standards, or water quality objectives applicable to oxygen 18/oxygen 16 ratio. 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.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 10742, Oxygen 18/Oxygen 16 ratio	Region 6
Mesquite Springs (Inyo County)

LOE ID:

21285

Pollutant:

Oxygen 18/Oxygen 16 ratio

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The reported oxygen 18/oxygen 16 ratios (as ml) in two samples were -13.84 and -13.86.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There are no state or federal standards, water quality objectives or criteria for oxygen 18/oxygen 16 ratio.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	7619	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	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 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 in that only one sample per year is available. 3. Neither of two samples exceeded the water quality objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 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 Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 7619, Oxygen, Dissolved	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5246

Pollutant:

Oxygen, Dissolved

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Dissolved oxygen concentrations in two samples were 7.5 and 8.3 mg/L.The objective was not exceeded, but sample numbers were too small for use with the Listing Policy's binomial model.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The applicable objective from Lahontan Basin Plan Table 3-6 is a 1- day minimum dissolved oxygen concentration of 4.0 mg/L for waters designated for the Cold Freshwater Habitat Use.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two dissolved oxygen samples were taken in 2002 and 2003.

Environmental Conditions:

The Mesquite Springs are within the Stovepipe Wells Hydrologic Subarea of the Amargosa Hydrologic Unit (HU No. 609.11). They supply drinking water to a campground. No site-specific water quality objectives apply to the springs. Chemical and radioactive constituents, including the salts that contribute to high specific conductance levels, come from natural sources. The Mesquite Springs are designated for both the Warm Freshwater Habitat and Cold Freshwater Habitat beneficial uses, and for the Rare, Threatened or Endangered Species Use.

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	10719	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	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 line(s) of evidence is available in the administrative record to assess this pollutant. There are no biological data available to assess whether any of the of the chemical samples exceeds the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. There are no biological data available to evaluate compliance with the objective and the data cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because no biological data are available for assessment of compliance with the applicable water quality objective.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 10719, Phosphate	Region 6
Mesquite Springs (Inyo County)

LOE ID:

6035

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. Concentrations of phosphate in two samples were 0.013 and 0.018 mg/L. No information on algae growth or other secondary indicators of eutrophication is available to permit evaluation of compliance with the biostimulatory substances objective.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There are no site-specific water quality objectives for Mesquite Springs. 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:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	10720	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. No biological data are available to assess whether 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 do not satisfy the data quality requirements of section 6.1.4 of the Policy due to an error in the SWAMP QAPP regarding holding times for total phosphorus samples. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. There are no biological data available for evaluation of compliance with the objective and the data cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there is a quality assurance problem with the chemical data and no biological data are available for assessment of compliance with the applicable water quality objective.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 10720, Phosphorus	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5801

Pollutant:

Phosphorus

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. Concentrations of Total Phosphorus in two samples were 0.012 and 0.018 mg/L. No information on algae growth or other secondary indicators of eutrophication is available to permit evaluation of compliance with the biostimulatory substances objective.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Sampling and analysis were done according to the SWAMP QAPP. However, in July 2009 an error was discovered in the QAPP related to holding times for total phosphorus samples that affects the validity of data for the Lahontan Region The holding time for samples that are not acid-preserved.should be 48 hours rather than 28 days as indicated in the QAPP. "Low level" phosphorus analyses, without acid preservation, are used in the Lahontan Region's SWAMP program. ..

QAPP Information Reference(s):


DECISION ID	10762	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. There are no applicable state or federal standards or criteria for potassium. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. There are no applicable water quality standards or criteria and the data cannot be assessed using Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 10762, Potassium	Region 6
Mesquite Springs (Inyo County)

LOE ID:

21255

Pollutant:

Potassium

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The concentrations of dissolved potassium in two samples were 13.4 and 7.8 mg/L.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There are no state or federal standards, water quality objectives or criteria for potassium.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	7611	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	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. Neither of the samples exceeds the California Toxics Rule standard or the California Maximum Contaminant Level. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. Neither of two samples exceeded the applicable standards 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.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 7611, Selenium	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5317

Pollutant:

Selenium

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. Dissolved selenium concentrations in two samples were 1.5 and 1.4 ug/L.The CTR standard was not exceeded.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Toxics Rule (CTR) 4 -day average aquatic life standard for selenium is 5 ug/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 7611, Selenium	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5316

Pollutant:

Selenium

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. Dissolved selenium concentrations in two samples were 1.5 and 1.4 ug/L.The MCL was not exceeded.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

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 selenium is 50 ug/L.
\

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	7766	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	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 analyte. RWQCB staff are not aware of any water quality standards, criteria, or guidelines for silica (silicon dioxide). Silica is a naturally occurring substance that is essential for some aquatic organisms (i.e., diatoms). Only two samples are available, and this number is insufficient for assessment using listing policy Table 3.2. 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.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no known standards, criteria or guidelines applicable to the pollutant, and the minimum sample number requirement of Listing Policy Table 3.2 are not met.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 7766, Silica	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5805

Pollutant:

Silica

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. Concentrations of dissolved silica in two samples were
69.9 and 67 mg/L. If standards or criteria were available, these sample numbers would be too small for assessment with Listing Policy Table 3-2.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There are no California or federal standards or criteria for silica (silicon dioxide) It is sometimes monitored because of its importance as a structural material in the cell walls of diatoms.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	10773	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	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 line(s) of evidence is available in the administrative record to assess this pollutant. There are no applicable standards or criteria for sodium for the protection of freshwater aquatic life. Two of the samples exceed the U.S. Environmental Protection Agency (USEPA) drinking water advisory level criterion. USEPA guidance states that the criterion is non-regulatory and that it applies to persons who must restrict their daily intake of sodium and should not be extrapolated to the general population. 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. Two of two samples exceeded the USEPA drinking water health advisory criterion 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 Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 10773, Sodium	Region 6
Mesquite Springs (Inyo County)

LOE ID:

21264

Pollutant:

Sodium

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The concentrations of dissolved sodium in two samples were 230 and 221 mg/L.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The U.S. Environmental Protection Agency's Drinking Water Health Advisory criterion for sodium is 20 mg/L.

Objective/Criterion Reference:

Drinking Water Advisory: Consumer Acceptability Advice and Health Effects Analysis

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 10773, Sodium	Region 6
Mesquite Springs (Inyo County)

LOE ID:

21260

Pollutant:

Sodium

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The concentrations of dissolved sodium in two samples were 230 and 221 mg/L.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There are no state or federal standards, water quality objectives or criteria for sodium for protection of aquatic life.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	7622	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	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 upper limit in the California Maximum Contaminant Level (MCL). 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 (one field measurement and two laboratory measurements taken over two years, are not temporally representative as required by section 6.1.5 of the Policy. 3. The single field measurement and two laboratory measurements did not exceed the MCL and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. However, the minimum sample number requirements of Table 3.2 were not met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision 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 available data do not meet the minimum sample number requirements of Listing Policy Table 3.2.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 7622, Specific Conductance	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5249

Pollutant:

Specific Conductance

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program.Two laboratory specific conductance measurements were, 1240 and 1150 uS/cm, and one field measurement was 1250 uS/cm. The recommended MCL was exceeded, but the upper limit was not. Sample numbers were too small for use with the Listing Policy's binomial model.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The recommended MCL for specific conductance is 900 microsiemens per centimeter (uS/cm). The MCL includes an upper limit of 1600 uS/cm, and a short term limit of 2200 uS/cm.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two laboratory measurements and one field measurement were taken in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	10723	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	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 applicable water quality criterion. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. Neither of two samples exceeded the water quality criterion and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision 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 criterion is not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 10723, Strontium	Region 6
Mesquite Springs (Inyo County)

LOE ID:

21286

Pollutant:

Strontium

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The reported concentrations of dissolved strontium in 2 samples were 320 and 344 ug/L. The criterion was not exceeded.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The U.S. Environmental Protection Agency's Significant No Adverse Risk Level (SNARL) criterion for strontium is 4000 ug/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	10749	Region 6
Mesquite Springs (Inyo County)

Pollutant:	Strontium 87/Strontium 86 ratio
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. There are no California or federal criteria, standards, or water quality objectives applicable to strontium 86/strontium 87 ratio. 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.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 10749, Strontium 87/Strontium 86 ratio	Region 6
Mesquite Springs (Inyo County)

LOE ID:

21280

Pollutant:

Strontium 87/Strontium 86 ratio

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The reported strontium 87/strontium 86 ratios in two samples (as ml) were 0.71112 and 0.71116.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There are no state or federal standards, water quality objectives or criteria for strontium 87/strontium 86 ratio..

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	7623	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Neither of the samples exceeds the California Maximum Contaminant Level (MCL). 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 in that only one sample per year is available. 3. Neither of two samples exceeded the MCL and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. However, the minimum sample number requirements of Table 3.2 are not met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 7623, Sulfates	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5253

Pollutant:

Sulfates

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Sulfate concentrations in two samples were 174 and 172 mg/L.. The MCL was not exceeded, but sample numbers were too small for use with the Listing Policy's binomial model.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

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 sulfate is 250 mg/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	7691	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	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.

Regional Board Decision 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 available data are insufficient for assessment under Listing Policy Table 3.2 and Section 3.10.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 7691, Temperature, water	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5259

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Two temperature measurements, were 25 and 22 degrees Celsius. Sampling frequency was inadequate to define the natural temperature regime or to determine whether changes have occurred.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Lahontan Basin Plan's objective for temperature states: Objective: "The natural receiving water temperature of all waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such an alteration in temperature does not adversely affect the water for beneficial uses.

For waters designated WARM, water temperature shall not be altered by more than five degrees Fahrenheit ... above or below the natural temperature. For waters designated COLD, the temperature shall not be altered."

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two measurements of water temperature were taken in 2002 and 2003. Sampling frequency was inadequate to define the natural temperature regime or to determine whether changes have occurred.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	10727	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. There are no California or federal criteria, standards, or water quality objectives applicable to titanium. 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.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there are no applicable water quality standards or criteria.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 10727, Titanium	Region 6
Mesquite Springs (Inyo County)

LOE ID:

6227

Pollutant:

Titanium

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. A radioactive isotope of titanium was measured. Two samples had activities of -0.2 and 0.1 picocuries per liter (pCi/L).

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There are no state or federal water quality standards or criteria for titanium.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 10727, Titanium	Region 6
Mesquite Springs (Inyo County)

LOE ID:

6228

Pollutant:

Titanium

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:

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There are no state or federal water quality standards or criteria for titanium. The Lahontan Basin Plan's narrative water quality objective for radioactivity states: "Radionuclides ahll not be present in concentrations which are deleterious to human, plant, animal or aquatic life nor which result in the accumulation of radionuclides in the food web to an extent which presents a hazard to human, plant, animal or aquatic life." The objective also references drinking water Maximum Contaminant Levels for radionuclides.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	7690	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Neither of the samples exceeds the upper limit in the California Maximum Contaminant Level (MCL). 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 in that only one sample per year is available. 3. Neither of two samples exceeded the MCL and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. However, the minimum sample number requirements of the Listing Policy are not met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 7690, Total Dissolved Solids	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5255

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. TDS concentrations in two samples were 827 and 820 mg/L. The recommended secondary MCL was exceeded, but the upper limit (1000 mg/L) was not. Sample numbers were too small for use with the Listing Policy's binomial model.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The recommended secondary MCL for Total Dissolved Solids (TDS) is 500 mg/L; however, 1000 mg/L is acceptable as an upper limit and 1500 mg/L is acceptable as a short term value.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	10696	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status One line of evidence is available in the administrative record to assess this pollutant. No biological data are available to determine whether either of the chemical samples exceeds the water quality objective for biostimulatory substances. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used 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 in that only one sample per year is available. 3. No biological data are available for assessment whether either of 2 samples exceeded the water quality objective, and the data cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because no biological data are available for assessment of compliance with the applicable water quality objective.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 10696, Total Kjeldahl Nitrogen (TKN)	Region 6
Mesquite Springs (Inyo County)

LOE ID:

21247

Pollutant:

Total Kjeldahl Nitrogen (TKN)

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. One of two samples for Total Kjeldahl nitrogen was below the detection level and the other was an estimated value. No information on algae growth or other secondary indicators of eutrophication is available to permit evaluation of compliance with the biostimulatory substances objective.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	10747	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	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. Neither of the samples exceeds the California Maximum Contaminant Level. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy in that only one sample per year is available. 3. Neither of two samples exceeded the MCL 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.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 10747, Tritium	Region 6
Mesquite Springs (Inyo County)

LOE ID:

21281

Pollutant:

Tritium

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The reported levels of tritium 2 were 0.64 and 0.58 pCi/L. The MCL was not exceeded.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

California Maximum Contaminant Levels (MCLs) apply to ambient waters designated for the MUN use under the Lahontan Basin Plan's objective for radioactivity. The MCL for tritium is 20,000 picocuries per liter (pCi/L).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	7769	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	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 exceed the California Maximum Contaminant Level, applicable under the Radioactivity 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 in that only one sample per year is available. 3. Neither of two samples exceeded the Maximum Contaminant Level 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.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 7769, Uranium	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5589

Pollutant:

Uranium

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 USGS sampled Mesquite Springs under the Region 6 SWAMP program. Dissolved uranium concentrations in two samples were 5.62 and 6.32 ug/L. Using the OEHHA conversion factor of 0.79 pCi per ug, based on studies of naturally occurring uranium in California, the equivalent values for the samples are 4.44 and 4.99 pCi/L. The MCL was not exceeded.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

2001. Public Health Goal for Uranium in Drinking Water. April 2001

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's water quality objective for radioactivity. The MCL for uranium is 20 picocuries per liter (pCi/L).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were taken in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	10687	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. There are no applicable water quality standards or criteria for protection of aquatic life. None of the samples exceeds the California Maximum Contaminant Level (MCL). 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 in that only one sample per year is available. 3. Neither of two samples exceeded the MCL 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.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 10687, Vanadium	Region 6
Mesquite Springs (Inyo County)

LOE ID:

21290

Pollutant:

Vanadium

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The reported concentrations of dissolved vanadium in 2 samples were 14.9 and 14.3 ug/L.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There are no applicable state or federal standards or criteria for vanadium for the protection of aquatic life.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 10687, Vanadium	Region 6
Mesquite Springs (Inyo County)

LOE ID:

21289

Pollutant:

Vanadium

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. The reported concentrations of dissolved vanadium in 2 samples were 14.9 and 14.3 ug/L. The MCL was not exceeded.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

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 vanadium is 50 ug/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	7614	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	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 applicable water quality objectives. 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 in that only one sample per year is available. 3. Neither of two samples exceeded the applicable objectives 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.

Regional Board Decision 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.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 7614, Zinc	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5320

Pollutant:

Zinc

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:

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Toxics Rule zinc standards for protection of freshwater aquatic life are dependent on hardness. At the reported hardness levels, the acute toxicity standard for zinc ranges from 139.65 to 142.53 ug/L, and the chronic toxicity standard ranges from 140.79 to 143.69 ug/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 7614, Zinc	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5318

Pollutant:

Zinc

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program in 2002 and 2003. One of two dissolved zinc samples was below the detection level and zinc in the other was detected but not quantified (USGS Code M) The MCL was not exceeded. (Note: MCLs for metals are expressed as total rather than dissolved, but only dissolved zinc data were available.)

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

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 zinc is 5000 ug/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	7689	Region 6
Mesquite Springs (Inyo County)

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

Regional Board Conclusion:	Two lines of evidence are available in the administrative record to assess this pollutant. For waters designated for the Cold Freshwater Habitat beneficial use,the Lahontan Basin Plan's narrative pH objective is a non-degradation objective, and sample numbers are insufficient to establish baseline conditions or detect trends as required under 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 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 in that only one sample per year is available. 3. It is not possible to determine whether the narrative pH objective was exceeded because the requirements of Listing Policy Section 3.10 were not met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision 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 data are insufficient to establish baseline and trend conditions as required under Listing Policy section 3.10.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 7689, pH	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5803

Pollutant:

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Two field pH measurements were both 7.9 units; two laboratory measurements were 8.1 and 7.9 units. Sample numbers were too small for use with the Listing Policy's binomial model, and were also too small to define normal pH levels or to detect change.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The U.S. Environmental Protection Agency's secondary drinking water Maximum Contaminant Level (MCL) criterion is a pH range of 6.5 to 8.5 units. (There is no California MCL for pH.)

Objective/Criterion Reference:

Compilation of Water Quality Goals

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two field measurements and two laboratory measurements of pH were taken in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 7689, pH	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5235

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:

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Lahontan Basin Plan's pH objective 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:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two field measurements and two laboratory measurements of pH were taken in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	9843	Region 6
Mesquite Springs (Inyo County)

Pollutant:	Arsenic
Final Listing Decision:	List on 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:	2021
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	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. Neither of the samples exceeds the California Toxics Rule aquatic life standards. Both of the samples exceed the California Maximum Contaminant Level (MCL). Although only one sample per year is available, the springs are from a groundwater source and water quality is expected to be more constant over time than the quality of a lake or stream. Listing is being recommended because the springs are an existing source of drinking water. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of 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 satisfy the data quantity requirements of section 6.1.5 of the Policy. Two of two samples exceed the MCL and this exceeds 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.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):	USEPA approved the listing of this water body as a water quality limited segment requiring a TMDL for this pollutant.

Line of Evidence (LOE) for Decision ID 9843, Arsenic	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5269

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Arsenic concentrations in two samples were 42.5 and 35.4 ug/L. Both samples exceeded the MCL.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

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 arsenic is 10 ug/L (effective November 28, 2008).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 9843, Arsenic	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5791

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

The U.S. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Arsenic concentrations in two samples were 42.5 and 35.4 ug/L. The California Toxics Rule standards were not exceeded.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Toxics Rule's freshwater aquatic life standards for arsenic are as follows: 4 day average = 150 ug/l; 1 hour average = 340 ug/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):


DECISION ID	9844	Region 6
Mesquite Springs (Inyo County)

Pollutant:	Boron
Final Listing Decision:	List on 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:	2021
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	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. Both of the samples exceed the water quality objective. Although only one sample per year is available, the springs come from a groundwater source with water quality expected to be less variable over time than the quality of a stream or lake. Listing is being recommended because the springs are an existing source of drinking water. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of 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 satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. Two of two samples exceed the California Maximum Contaminant Level and this exceeds 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.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

USEPA Action (if applicable):	USEPA approved the listing of this water body as a water quality limited segment requiring a TMDL for this pollutant.

Line of Evidence (LOE) for Decision ID 9844, Boron	Region 6
Mesquite Springs (Inyo County)

LOE ID:

5806

Pollutant:

Boron

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. Geological Survey sampled Mesquite Springs under the Region 6 SWAMP program. Boron concentrations in two samples were 1280 and 1460 ug/L, both exceeding the criterion.

Data Reference:

2007. SWAMP Data for the Amargosa Hydrologic Unit

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Department of Health Services "Notification Level for Drinking Water " criterion for boron is 1000 ug/L. This is a health-based criterion that applies to drinking water systems.

Objective/Criterion Reference:

Compilation of Water Quality Goals

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station, Mesquite Spring (in Death Valley National Park, near Scottys Castle), was sampled.

Temporal Representation:

Two samples were collected in 2002 and 2003.

Environmental Conditions:

QAPP Information:

Data meet the quality assurance requirements of the SWAMP QAPP.

QAPP Information Reference(s):