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

Supporting Information

Regional Board 6 - Lahontan Region

Water Body Name:	Middle Martis Creek (Placer County)
Water Body ID:	CAR6352004020230502031705
Water Body Type:	River & Stream


DECISION ID	162816	Region 6
Middle 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	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 162816, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 6
Middle Martis Creek (Placer County)

LOE ID:

338791

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:

Water Board staff assessed Truckee River Water Quality Monitoring Plan data for Middle Martis Creek (Placer County) to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Nitrate + Nitrite 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 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-MC3 (DST-MC3 Middle Martis Creek upstream of confluence with main stem).

Temporal Representation:

The samples were collected between the dates of 2010-12-18 and 2012-03-16

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	170093	Region 6
Middle 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 170093, Nitrogen	Region 6
Middle Martis Creek (Placer County)

LOE ID:

347829

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 3 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-MC3 Middle Martis Creek upstream of confluence with main stem (DST-MC3)

Temporal Representation:

The samples were collected between the dates of 2015-02-07 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 170093, Nitrogen	Region 6
Middle Martis Creek (Placer County)

LOE ID:

347838

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 1 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: TURB-MC4 Middle Martis Creek upstream of SR 267 crossing (TURB-MC4)

Temporal Representation:

The samples were collected between the dates of 2015-02-07 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 170093, Nitrogen	Region 6
Middle Martis Creek (Placer County)

LOE ID:

347825

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-MC7 Middle Martis Creek (DST-MC7)

Temporal Representation:

The samples were collected between the dates of 2015-02-07 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	170091	Region 6
Middle 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 170091, Nitrogen, Nitrate	Region 6
Middle Martis Creek (Placer County)

LOE ID:

347764

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-MC3 Middle Martis Creek upstream of confluence with main stem (DST-MC3)

Temporal Representation:

The samples were collected between the dates of 2012-11-30 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 170091, Nitrogen, Nitrate	Region 6
Middle Martis Creek (Placer County)

LOE ID:

347753

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-MC7 Middle Martis Creek (DST-MC7)

Temporal Representation:

The samples were collected between the dates of 2012-11-30 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 170091, Nitrogen, Nitrate	Region 6
Middle Martis Creek (Placer County)

LOE ID:

347751

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-MC3 Middle Martis Creek upstream of confluence with main stem (DST-MC3)

Temporal Representation:

The samples were collected between the dates of 2012-11-30 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	169024	Region 6
Middle 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. 10 of the 24 samples exceed the basin plan 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. 10 of 24 samples exceed the basin plan 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 169024, Phosphorus	Region 6
Middle Martis Creek (Placer County)

LOE ID:

347893

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 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-MC3 Middle Martis Creek upstream of confluence with main stem (DST-MC3)

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 169024, Phosphorus	Region 6
Middle Martis Creek (Placer County)

LOE ID:

347922

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: TURB-MC4 Middle Martis Creek upstream of SR 267 crossing (TURB-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 169024, Phosphorus	Region 6
Middle Martis Creek (Placer County)

LOE ID:

347891

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-MC7 Middle Martis Creek (DST-MC7)

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 169024, Phosphorus	Region 6
Middle Martis Creek (Placer County)

LOE ID:

347905

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: TURB-MC4 Middle Martis Creek upstream of SR 267 crossing (TURB-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 169024, Phosphorus	Region 6
Middle Martis Creek (Placer County)

LOE ID:

347908

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-MC3 Middle Martis Creek upstream of confluence with main stem (DST-MC3)

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 169024, Phosphorus	Region 6
Middle Martis Creek (Placer County)

LOE ID:

347912

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:
3 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-MC3 Middle Martis Creek upstream of confluence with main stem (DST-MC3)

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 169024, Phosphorus	Region 6
Middle Martis Creek (Placer County)

LOE ID:

347898

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-MC3 Middle Martis Creek upstream of confluence with main stem (DST-MC3)

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 169024, Phosphorus	Region 6
Middle Martis Creek (Placer County)

LOE ID:

347914

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-MC7 Middle Martis Creek (DST-MC7)

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


DECISION ID	170092	Region 6
Middle 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. Three lines of evidence are available in the administrative record to assess this pollutant. Two of the 7 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. Two of 7 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 170092, Total Kjeldahl Nitrogen (TKN)	Region 6
Middle Martis Creek (Placer County)

LOE ID:

348032

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:
1 of 1 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: TURB-MC4 Middle Martis Creek upstream of SR 267 crossing (TURB-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 170092, Total Kjeldahl Nitrogen (TKN)	Region 6
Middle Martis Creek (Placer County)

LOE ID:

348009

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-MC3 Middle Martis Creek upstream of confluence with main stem (DST-MC3)

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 170092, Total Kjeldahl Nitrogen (TKN)	Region 6
Middle Martis Creek (Placer County)

LOE ID:

348006

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-MC7 Middle Martis Creek (DST-MC7)

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 170092, Total Kjeldahl Nitrogen (TKN)	Region 6
Middle Martis Creek (Placer County)

LOE ID:

348013

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-MC3 Middle Martis Creek upstream of confluence with main stem (DST-MC3)

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	163831	Region 6
Middle 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. Three lines of evidence are available in the administrative record to assess this pollutant. Eight of the 8 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. Eight of 8 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 163831, Turbidity	Region 6
Middle Martis Creek (Placer County)

LOE ID:

343500

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:

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: TURB-MC4 Middle Martis Creek upstream of SR 267 crossing (TURB-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 163831, Turbidity	Region 6
Middle Martis Creek (Placer County)

LOE ID:

343489

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-MC3 Middle Martis Creek upstream of confluence with main stem (DST-MC3)

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 163831, Turbidity	Region 6
Middle Martis Creek (Placer County)

LOE ID:

343499

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-MC7 Middle Martis Creek (DST-MC7)

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 163831, Turbidity	Region 6
Middle Martis Creek (Placer County)

LOE ID:

343493

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:

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-MC3 Middle Martis Creek upstream of confluence with main stem (DST-MC3)

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