Draft California 2026 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 6 - Lahontan Region

Water Body Name:	West Martis Creek (Placer County)
Water Body ID:	CAR6352004020230502032103
Water Body Type:	River & Stream


DECISION ID	171797	Region 6
West Martis Creek (Placer County)

Pollutant:	Benthic Community Effects
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:	Benthic Community Effects are being considered for placement on the CWA section 303(d) List under sections 3.9 of the Listing Policy. Under section 3.9, additional lines of evidence (LOEs) associating the Benthic Community Effects decision with a water or sediment concentration of pollutants other than benthic-macroinvertebrate bioassessment or habitat assessment LOEs are necessary to place a water body on the 303(d) List for Benthic Community Effects. Three lines of evidence evaluating benthic-macroinvertebrate bioassessment data are available in the administrative record to assess this indicator. Zero of fifteen benthic-macroinvertebrate samples exceed the California Stream Condition Index (CSCI) impairment threshold. These data indicate that the waterbody is likely unimpaired for Benthic Community Effects and therefore no other pollutant LOEs need be associated with this decision at this time. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing Benthic Community Effects in this waterbody segment on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of fifteen benthic-macroinvertebrate bioassessment samples had CSCI scores below 0.79. Therefore, this water body is not exceeding the water quality threshold for the protection of the COLD beneficial use. The available information indicates that the waterbody/pollutant combination should not be placed on the 303(d) List of impaired waters at this time. 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:

Line of Evidence (LOE) for Decision ID 171797, Benthic Community Effects	Region 6
West Martis Creek (Placer County)

LOE ID:

352917

Pollutant:

Benthic-Macroinvertebrate Bioassessments

LOE Subgroup:

Population/Community Degradation

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Benthic macroinvertebrate surveys

Data Used to Assess Water Quality:

Water Board staff assessed data for BIO-MC3 to determine beneficial use support and the results are as follows: 0 of 5 samples exceeded the water quality standard. CSCI scores were from 1.0493483237 to 1.1937383793 .

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Lahontan Basin Plan)

Objective/Criterion Reference:

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

Evaluation Guideline:

The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rhen, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.)

Guideline Reference:

Bioassessment in complex environments: designing an index for consistent meaning in different settings

Spatial Representation:

The samples were collected at 1 monitoring site: BIO-MC3 (BIO-MC3 West Martis Creek).

Temporal Representation:

Samples were collected from 2010-09-09 to 2018-09-20.

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 171797, Benthic Community Effects	Region 6
West Martis Creek (Placer County)

LOE ID:

352918

Pollutant:

Benthic-Macroinvertebrate Bioassessments

LOE Subgroup:

Population/Community Degradation

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Benthic macroinvertebrate surveys

Data Used to Assess Water Quality:

Water Board staff assessed data for BIO-MC4 to determine beneficial use support and the results are as follows: 0 of 5 samples exceeded the water quality standard. CSCI scores were from 0.90005305504 to 1.1241150436 .

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Bioassessment in complex environments: designing an index for consistent meaning in different settings

Spatial Representation:

The samples were collected at 1 monitoring site: BIO-MC4 (BIO-MC4 West Martis Creek).

Temporal Representation:

Samples were collected from 2010-09-29 to 2018-09-19.

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 171797, Benthic Community Effects	Region 6
West Martis Creek (Placer County)

LOE ID:

352915

Pollutant:

Benthic-Macroinvertebrate Bioassessments

LOE Subgroup:

Population/Community Degradation

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Benthic macroinvertebrate surveys

Data Used to Assess Water Quality:

Water Board staff assessed data for BIO-MC1 to determine beneficial use support and the results are as follows: 0 of 5 samples exceeded the water quality standard. CSCI scores were from 1.0320316867 to 1.1600078591 .

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Bioassessment in complex environments: designing an index for consistent meaning in different settings

Spatial Representation:

The samples were collected at 1 monitoring site: BIO-MC1 (BIO-MC1 Upper Martis Creek).

Temporal Representation:

Samples were collected from 2010-09-30 to 2018-09-21.

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639


DECISION ID	170288	Region 6
West Martis Creek (Placer County)

Pollutant:	Nitrogen
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:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

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. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB 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.

Line of Evidence (LOE) for Decision ID 170288, Nitrogen	Region 6
West Martis Creek (Placer County)

LOE ID:

347824

Pollutant:

Total Nitrogen as N

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Truckee River Water Quality Monitoring Plan data to determine beneficial use support and results are as follows:
0 of 2 samples exceeded the water quality threshold for Nitrogen, Total

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for Nitrogen, Total in this water body is 1.45 (mg/L), (as a MOMMPR).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: DST-MC8 Upper West Martis Creek - West (DST-MC8)

Temporal Representation:

The samples were collected between the dates of 2014-12-03 and 2019-04-24

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 170288, Nitrogen	Region 6
West Martis Creek (Placer County)

LOE ID:

347823

Pollutant:

Total Nitrogen as N

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Truckee River Water Quality Monitoring Plan data to determine beneficial use support and results are as follows:
1 of 4 samples exceeded the water quality threshold for Nitrogen, Total

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for Nitrogen, Total in this water body is 1.45 (mg/L), (as a MOMMPR).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: DST-MC4 West Martis Creek downstream of Northstar Golf Course (DST-MC4)

Temporal Representation:

The samples were collected between the dates of 2014-12-03 and 2019-04-24

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 170288, Nitrogen	Region 6
West Martis Creek (Placer County)

LOE ID:

347832

Pollutant:

Total Nitrogen as N

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for Nitrogen, Total in this water body is 1.45 (mg/L), (as a MOMMPR).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: DST-MC9 Upper West Martis Creek - East (DST-MC9)

Temporal Representation:

The samples were collected between the dates of 2014-12-03 and 2019-04-24

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 170288, Nitrogen	Region 6
West Martis Creek (Placer County)

LOE ID:

347826

Pollutant:

Total Nitrogen as N

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for Nitrogen, Total in this water body is 1.45 (mg/L), (as a MOMMPR).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: DST-MC4 West Martis Creek downstream of Northstar Golf Course (DST-MC4)

Temporal Representation:

The samples were collected between the dates of 2014-12-03 and 2019-04-24

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639


DECISION ID	170285	Region 6
West Martis Creek (Placer County)

Pollutant:	Nitrogen, 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:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

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. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB 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.

Line of Evidence (LOE) for Decision ID 170285, Nitrogen, Nitrate	Region 6
West Martis Creek (Placer County)

LOE ID:

347748

Pollutant:

Nitrogen, Nitrate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Truckee River Water Quality Monitoring Plan data to determine beneficial use support and results are as follows:
0 of 4 samples exceeded the water quality threshold for Nitrate as N

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for Nitrate as N in this water body is 1 (mg/L), (as a MOMMPR).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: DST-MC4 West Martis Creek downstream of Northstar Golf Course (DST-MC4)

Temporal Representation:

The samples were collected between the dates of 2012-11-17 and 2019-04-24

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 170285, Nitrogen, Nitrate	Region 6
West Martis Creek (Placer County)

LOE ID:

347755

Pollutant:

Nitrogen, Nitrate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for Nitrate as N in this water body is 1 (mg/L), (as a MOMMPR).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: DST-MC8 Upper West Martis Creek - West (DST-MC8)

Temporal Representation:

The samples were collected between the dates of 2012-11-17 and 2019-04-24

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 170285, Nitrogen, Nitrate	Region 6
West Martis Creek (Placer County)

LOE ID:

347750

Pollutant:

Nitrogen, Nitrate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for Nitrate as N in this water body is 1 (mg/L), (as a MOMMPR).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: DST-MC9 Upper West Martis Creek - East (DST-MC9)

Temporal Representation:

The samples were collected between the dates of 2012-11-17 and 2019-04-24

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 170285, Nitrogen, Nitrate	Region 6
West Martis Creek (Placer County)

LOE ID:

347752

Pollutant:

Nitrogen, Nitrate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for Nitrate as N in this water body is 1 (mg/L), (as a MOMMPR).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: DST-MC4 West Martis Creek downstream of Northstar Golf Course (DST-MC4)

Temporal Representation:

The samples were collected between the dates of 2012-11-17 and 2019-04-24

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639


DECISION ID	162868	Region 6
West Martis Creek (Placer 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 CWA 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. Nine lines of evidence are available in the administrative record to assess this parameter: 3 which assess dissolved oxygen concentration data and 6 which assess dissolved oxygen percent saturation data. Zero of 39 samples are below the objective for minimum dissolved oxygen concentration. One of 27 samples is below the objective for minimum dissolved oxygen percent saturation. 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 CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of 39 samples are below the objective for minimum dissolved oxygen concentration. One of 27 samples is below the objective for minimum dissolved oxygen percent saturation. 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:

Line of Evidence (LOE) for Decision ID 162868, Oxygen, Dissolved	Region 6
West Martis Creek (Placer County)

LOE ID:

339332

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan for the Lahontan Region's water quality objective states that the dissolved oxygen concentration shall not be less than 80 percent of saturation.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: BIO-MC3 (BIO-MC3 West Martis Creek).

Temporal Representation:

The samples were collected between the dates of 2012-09-06 and 2018-09-20

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 162868, Oxygen, Dissolved	Region 6
West Martis Creek (Placer County)

LOE ID:

351194

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Truckee River Water Quality Monitoring Plan data to determine beneficial use support and results are as follows:
0 of 5 samples fell below the minimum water quality threshold for Oxygen, Dissolved

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for Oxygen, Dissolved in this water body is 80 (%), (as a Min).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: BIO-MC4 West Martis Creek (BIO-MC4)

Temporal Representation:

The samples were collected between the dates of 2010-09-29 and 2018-09-19

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 162868, Oxygen, Dissolved	Region 6
West Martis Creek (Placer County)

LOE ID:

339453

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan for the Lahontan Region's water quality objective states that the dissolved oxygen concentration shall not be less than 80 percent of saturation.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: BIO-MC1 (BIO-MC1 Upper Martis Creek).

Temporal Representation:

The samples were collected between the dates of 2012-08-21 and 2018-09-21

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 162868, Oxygen, Dissolved	Region 6
West Martis Creek (Placer County)

LOE ID:

339452

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan for the Lahontan Region's water quality objective states that the dissolved oxygen concentration shall not be less than 80 percent of saturation.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: BIO-MC4 (BIO-MC4 West Martis Creek).

Temporal Representation:

The samples were collected between the dates of 2012-09-17 and 2018-09-19

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 162868, Oxygen, Dissolved	Region 6
West Martis Creek (Placer County)

LOE ID:

351209

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for Oxygen, Dissolved in this water body is 80 (%), (as a Min).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: BIO-MC1 Schaeffer Branch, Upper Martis Creek (BIO-MC1)

Temporal Representation:

The samples were collected between the dates of 2010-09-30 and 2018-09-21

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 162868, Oxygen, Dissolved	Region 6
West Martis Creek (Placer County)

LOE ID:

351217

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for Oxygen, Dissolved in this water body is 80 (%), (as a Min).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: BIO-MC3 West Martis Creek (BIO-MC3)

Temporal Representation:

The samples were collected between the dates of 2010-09-09 and 2018-09-20

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 162868, Oxygen, Dissolved	Region 6
West Martis Creek (Placer County)

LOE ID:

351334

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Truckee River Water Quality Monitoring Plan data to determine beneficial use support and results are as follows:
0 of 13 samples fell below the minimum water quality threshold for Oxygen, Dissolved

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for Oxygen, Dissolved in this water body is 7 (mg/L), (as a Min).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: BIO-MC1 Schaeffer Branch, Upper Martis Creek (BIO-MC1)

Temporal Representation:

The samples were collected between the dates of 2010-09-09 and 2018-09-21

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 162868, Oxygen, Dissolved	Region 6
West Martis Creek (Placer County)

LOE ID:

351311

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for Oxygen, Dissolved in this water body is 7 (mg/L), (as a Min).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: BIO-MC4 West Martis Creek (BIO-MC4)

Temporal Representation:

The samples were collected between the dates of 2010-09-09 and 2018-09-21

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 162868, Oxygen, Dissolved	Region 6
West Martis Creek (Placer County)

LOE ID:

351342

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for Oxygen, Dissolved in this water body is 7 (mg/L), (as a Min).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: BIO-MC3 West Martis Creek (BIO-MC3)

Temporal Representation:

The samples were collected between the dates of 2010-09-09 and 2018-09-21

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639


DECISION ID	170286	Region 6
West Martis Creek (Placer County)

Pollutant:	Specific Conductivity
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:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

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. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB 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.

Line of Evidence (LOE) for Decision ID 170286, Specific Conductivity	Region 6
West Martis Creek (Placer County)

LOE ID:

340562

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water designated as MUN shall not contain concentrations of chemical constituents in excess of the maximum contaminant level (MCL) or secondary maximum contaminant level (SMCL) based upon drinking water standards specified in Title 22 of the California Code of Regulations (Water Quality Control Plan, Lahontan Region).

Objective/Criterion Reference:

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

Evaluation Guideline:

California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's 'Chemical Constituents' objective. The California Secondary MCL for specific conductivity is 900 uS/cm.

Guideline Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Spatial Representation:

The samples were collected at 1 monitoring site: BIO-MC4 (BIO-MC4 West Martis Creek).

Temporal Representation:

The samples were collected between the dates of 2010-09-29 and 2018-09-19

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 170286, Specific Conductivity	Region 6
West Martis Creek (Placer County)

LOE ID:

340384

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Spatial Representation:

The samples were collected at 1 monitoring site: BIO-MC1 (BIO-MC1 Upper Martis Creek).

Temporal Representation:

The samples were collected between the dates of 2010-09-30 and 2018-09-21

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 170286, Specific Conductivity	Region 6
West Martis Creek (Placer County)

LOE ID:

340435

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Spatial Representation:

The samples were collected at 1 monitoring site: BIO-MC3 (BIO-MC3 West Martis Creek).

Temporal Representation:

The samples were collected between the dates of 2010-09-09 and 2018-09-20

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639


DECISION ID	162869	Region 6
West Martis Creek (Placer 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:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

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. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 162869, pH	Region 6
West Martis Creek (Placer County)

LOE ID:

339641

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Truckee River Water Quality Monitoring Plan data for West Martis Creek (Placer County) to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for pH. The objective for this pollutant requires background information that is currently unavailable, and therefore an assessment of water quality thresholds could not be made.

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Lahontan Basin Plan's regionwide objective for pH states: 'In fresh waters with designated beneficial uses of COLD or WARM, changes in normal ambient pH levels shall not exceed 0.5 pH units. For all other waters of the region, the pH shall not be depressed below 6.5 nor raised above 8.5 units. The Regional Board recognizes that some waters of the Region may have natural pH levels outside of the 6.5 to 8.5 range. Compliance with the pH objective for these waters will be determined on a case-by-case basis.'

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: BIO-MC1 (BIO-MC1 Upper Martis Creek).

Temporal Representation:

The samples were collected between the dates of 2010-09-30 and 2018-09-21

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 162869, pH	Region 6
West Martis Creek (Placer County)

LOE ID:

339846

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: BIO-MC1 (BIO-MC1 Upper Martis Creek).

Temporal Representation:

The samples were collected between the dates of 2010-09-30 and 2018-09-21

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 162869, pH	Region 6
West Martis Creek (Placer County)

LOE ID:

339736

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: BIO-MC4 (BIO-MC4 West Martis Creek).

Temporal Representation:

The samples were collected between the dates of 2010-09-29 and 2018-09-19

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 162869, pH	Region 6
West Martis Creek (Placer County)

LOE ID:

339939

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: BIO-MC4 (BIO-MC4 West Martis Creek).

Temporal Representation:

The samples were collected between the dates of 2010-09-29 and 2018-09-19

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 162869, pH	Region 6
West Martis Creek (Placer County)

LOE ID:

339540

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: BIO-MC3 (BIO-MC3 West Martis Creek).

Temporal Representation:

The samples were collected between the dates of 2010-09-09 and 2018-09-20

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 162869, pH	Region 6
West Martis Creek (Placer County)

LOE ID:

339976

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: BIO-MC3 (BIO-MC3 West Martis Creek).

Temporal Representation:

The samples were collected between the dates of 2010-09-09 and 2018-09-20

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639


DECISION ID	169029	Region 6
West Martis Creek (Placer County)

Pollutant:	Phosphorus
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Sources:	A Source Unknown
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA 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. Eight lines of evidence are available in the administrative record to assess this pollutant, four for Phosphorus with a dissolved fraction and four for Phosphorus with a total fraction. One of 14 samples exceed the objective in the LOE with a dissolved fraction, and 9 of 20 samples exceed the objective in the LOE with a total fraction. This decision is based on the total fraction LOE. 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 CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. 9 of 20 samples exceed the objective 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:

Line of Evidence (LOE) for Decision ID 169029, Phosphorus	Region 6
West Martis Creek (Placer County)

LOE ID:

347902

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:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for Phosphorus as P in this water body is 0.05 (mg/L), (as a MOMMPR).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: DST-MC9 Upper West Martis Creek - East (DST-MC9)

Temporal Representation:

The samples were collected between the dates of 2010-12-14 and 2019-04-24

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 169029, Phosphorus	Region 6
West Martis Creek (Placer County)

LOE ID:

347906

Pollutant:

Phosphorus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Truckee River Water Quality Monitoring Plan data to determine beneficial use support and results are as follows:
2 of 4 samples exceeded the water quality threshold for Phosphorus as P

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for Phosphorus as P in this water body is 0.05 (mg/L), (as a MOMMPR).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: DST-MC4 West Martis Creek downstream of Northstar Golf Course (DST-MC4)

Temporal Representation:

The samples were collected between the dates of 2010-12-14 and 2021-04-19

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 169029, Phosphorus	Region 6
West Martis Creek (Placer County)

LOE ID:

347897

Pollutant:

Phosphorus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Truckee River Water Quality Monitoring Plan data to determine beneficial use support and results are as follows:
4 of 8 samples exceeded the water quality threshold for Phosphorus as P

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for Phosphorus as P in this water body is 0.05 (mg/L), (as a MOMMPR).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: DST-MC4 West Martis Creek downstream of Northstar Golf Course (DST-MC4)

Temporal Representation:

The samples were collected between the dates of 2010-12-14 and 2021-04-19

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 169029, Phosphorus	Region 6
West Martis Creek (Placer County)

LOE ID:

347909

Pollutant:

Phosphorus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for Phosphorus as P in this water body is 0.05 (mg/L), (as a MOMMPR).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: DST-MC9 Upper West Martis Creek - East (DST-MC9)

Temporal Representation:

The samples were collected between the dates of 2010-12-14 and 2021-04-19

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 169029, Phosphorus	Region 6
West Martis Creek (Placer County)

LOE ID:

347918

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:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for Phosphorus as P in this water body is 0.05 (mg/L), (as a MOMMPR).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: DST-MC4 West Martis Creek downstream of Northstar Golf Course (DST-MC4)

Temporal Representation:

The samples were collected between the dates of 2010-12-14 and 2019-04-24

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 169029, Phosphorus	Region 6
West Martis Creek (Placer County)

LOE ID:

347901

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:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for Phosphorus as P in this water body is 0.05 (mg/L), (as a MOMMPR).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: DST-MC8 Upper West Martis Creek - West (DST-MC8)

Temporal Representation:

The samples were collected between the dates of 2010-12-14 and 2019-04-24

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 169029, Phosphorus	Region 6
West Martis Creek (Placer County)

LOE ID:

347911

Pollutant:

Phosphorus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for Phosphorus as P in this water body is 0.05 (mg/L), (as a MOMMPR).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: DST-MC8 Upper West Martis Creek - West (DST-MC8)

Temporal Representation:

The samples were collected between the dates of 2010-12-14 and 2021-04-19

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 169029, Phosphorus	Region 6
West Martis Creek (Placer County)

LOE ID:

347895

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:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Truckee River Water Quality Monitoring Plan data to determine beneficial use support and results are as follows:
1 of 6 samples exceeded the water quality threshold for Phosphorus as P

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for Phosphorus as P in this water body is 0.05 (mg/L), (as a MOMMPR).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: DST-MC4 West Martis Creek downstream of Northstar Golf Course (DST-MC4)

Temporal Representation:

The samples were collected between the dates of 2010-12-14 and 2019-04-24

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639


DECISION ID	170287	Region 6
West Martis Creek (Placer County)

Pollutant:	Total Kjeldahl Nitrogen (TKN)
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Sources:	A Source Unknown
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA 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. Four lines of evidence are available in the administrative record to assess this pollutant. Four of the 14 samples exceed the objective. 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 CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Four of 14 samples exceed the objective 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:

Line of Evidence (LOE) for Decision ID 170287, Total Kjeldahl Nitrogen (TKN)	Region 6
West Martis Creek (Placer County)

LOE ID:

348005

Pollutant:

Total Kjeldahl Nitrogen (TKN)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Truckee River Water Quality Monitoring Plan data to determine beneficial use support and results are as follows:
2 of 6 samples exceeded the water quality threshold for Nitrogen, Total Kjeldahl

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for Nitrogen, Total Kjeldahl in this water body is 0.45 (mg/L), (as a MOMMPR).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: DST-MC4 West Martis Creek downstream of Northstar Golf Course (DST-MC4)

Temporal Representation:

The samples were collected between the dates of 2010-12-14 and 2019-04-24

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 170287, Total Kjeldahl Nitrogen (TKN)	Region 6
West Martis Creek (Placer County)

LOE ID:

348015

Pollutant:

Total Kjeldahl Nitrogen (TKN)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for Nitrogen, Total Kjeldahl in this water body is 0.45 (mg/L), (as a MOMMPR).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: DST-MC4 West Martis Creek downstream of Northstar Golf Course (DST-MC4)

Temporal Representation:

The samples were collected between the dates of 2010-12-14 and 2019-04-24

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 170287, Total Kjeldahl Nitrogen (TKN)	Region 6
West Martis Creek (Placer County)

LOE ID:

348019

Pollutant:

Total Kjeldahl Nitrogen (TKN)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for Nitrogen, Total Kjeldahl in this water body is 0.45 (mg/L), (as a MOMMPR).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: DST-MC9 Upper West Martis Creek - East (DST-MC9)

Temporal Representation:

The samples were collected between the dates of 2010-12-14 and 2019-04-24

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 170287, Total Kjeldahl Nitrogen (TKN)	Region 6
West Martis Creek (Placer County)

LOE ID:

348010

Pollutant:

Total Kjeldahl Nitrogen (TKN)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for Nitrogen, Total Kjeldahl in this water body is 0.45 (mg/L), (as a MOMMPR).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: DST-MC8 Upper West Martis Creek - West (DST-MC8)

Temporal Representation:

The samples were collected between the dates of 2010-12-14 and 2019-04-24

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639


DECISION ID	163840	Region 6
West Martis Creek (Placer County)

Pollutant:	Turbidity
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Sources:	A Source Unknown
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA 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. Four lines of evidence are available in the administrative record to assess this pollutant. Sixteen of the 16 samples exceed the objective. 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 CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Sixteen of 16 samples exceed the objective and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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:

Line of Evidence (LOE) for Decision ID 163840, Turbidity	Region 6
West Martis Creek (Placer County)

LOE ID:

343496

Pollutant:

Turbidity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Truckee River Water Quality Monitoring Plan data to determine beneficial use support and results are as follows:
4 of 4 samples exceeded the water quality threshold for Turbidity

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for Turbidity in this water body is 3 (NTU), (as a MOMM).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: DST-MC4 West Martis Creek downstream of Northstar Golf Course (DST-MC4)

Temporal Representation:

The samples were collected between the dates of 2010-12-14 and 2020-11-18

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 163840, Turbidity	Region 6
West Martis Creek (Placer County)

LOE ID:

343487

Pollutant:

Turbidity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Truckee River Water Quality Monitoring Plan data to determine beneficial use support and results are as follows:
3 of 3 samples exceeded the water quality threshold for Turbidity

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for Turbidity in this water body is 3 (NTU), (as a MOMM).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: DST-MC8 Upper West Martis Creek - West (DST-MC8)

Temporal Representation:

The samples were collected between the dates of 2010-12-14 and 2020-11-18

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 163840, Turbidity	Region 6
West Martis Creek (Placer County)

LOE ID:

343486

Pollutant:

Turbidity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Truckee River Water Quality Monitoring Plan data to determine beneficial use support and results are as follows:
2 of 2 samples exceeded the water quality threshold for Turbidity

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for Turbidity in this water body is 3 (NTU), (as a MOMM).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: DST-MC9 Upper West Martis Creek - East (DST-MC9)

Temporal Representation:

The samples were collected between the dates of 2010-12-14 and 2020-11-18

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639

Line of Evidence (LOE) for Decision ID 163840, Turbidity	Region 6
West Martis Creek (Placer County)

LOE ID:

343495

Pollutant:

Turbidity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Truckee River Water Quality Monitoring Plan data to determine beneficial use support and results are as follows:
7 of 7 samples exceeded the water quality threshold for Turbidity

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for Turbidity in this water body is 3 (NTU), (as a MOMM).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: DST-MC4 West Martis Creek downstream of Northstar Golf Course (DST-MC4)

Temporal Representation:

The samples were collected between the dates of 2010-12-14 and 2020-11-18

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639


DECISION ID	162867	Region 6
West Martis Creek (Placer 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	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA 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. Zero of the 10 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 CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the 10 samples exceed the water quality objective and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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:

Line of Evidence (LOE) for Decision ID 162867, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 6
West Martis Creek (Placer County)

LOE ID:

338822

Pollutant:

Nitrate/Nitrite (Nitrite + Nitrate as N)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Water Quality Monitoring Plan for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for nitrate + nitrite (as N) that is incorporated by reference in the Water Quality Control Plan, Lahontan Region is 10.0 mg/L (Water Quality Control Plan, Lahontan Region).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: DST-MC4 (DST-MC4 West Martis Creek downstream of Northstar Golf Course).

Temporal Representation:

The samples were collected between the dates of 2010-12-18 and 2012-04-26

Environmental Conditions:

QAPP Information:

TRWQMP QAPP Equivalent

QAPP Information Reference(s):

Lahontan Water Board - TRWQMP_QAPP equivalent - Truckee River Water Quality Monitoring Plan - 402639