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

Supporting Information

Regional Board 6 - Lahontan Region

Water Body Name:	East Martis Creek
Water Body ID:	CAR6352004020171102046321
Water Body Type:	River & Stream


DECISION ID	168685	Region 6
East Martis Creek

Pollutant:	Ammonia
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 168685, Ammonia	Region 6
East Martis Creek

LOE ID:

338312

Pollutant:

Ammonia (Unionized)

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 Watershed Council data for East Martis Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Ammonia as N, Unionized.

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Watershed Council for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The un-ionized ammonia water quality objective to protect aquatic life in freshwater is temperature and pH dependent and is calculated according to the equation for the four-day criterion defined in Chapter 3 of The Water Quality Control Plan for the 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: MTREMAR (East Martis Creek at bridge).

Temporal Representation:

The samples were collected between the dates of 2017-09-23 and 2020-10-03

Environmental Conditions:

QAPP Information:

QAPP for Truckee River Monitoring Plan

QAPP Information Reference(s):

Quality Assurance Project Plan (QAPP) for Truckee River Monitoring Plan.

Line of Evidence (LOE) for Decision ID 168685, Ammonia	Region 6
East Martis Creek

LOE ID:

338099

Pollutant:

Nitrogen, ammonia (Total Ammonia)

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 Watershed Council for the 2026 Integrated Report in Region 6

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The total ammonia water quality objective to protect aquatic life in freshwater is temperature and pH dependent and is calculated according to the equation for the four-day criterion defined in Chapter 3 of The Water Quality Control Plan for the 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: MTREMAR (East Martis Creek at bridge).

Temporal Representation:

The samples were collected between the dates of 2017-09-23 and 2020-10-03

Environmental Conditions:

QAPP Information:

QAPP for Truckee River Monitoring Plan

QAPP Information Reference(s):

Quality Assurance Project Plan (QAPP) for Truckee River Monitoring Plan.


DECISION ID	170909	Region 6
East Martis Creek

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. One line of evidence evaluating benthic-macroinvertebrate bioassessment data is available in the administrative record to assess this indicator. Zero of five 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 five 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 170909, Benthic Community Effects	Region 6
East Martis Creek

LOE ID:

352920

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-MC6 to determine beneficial use support and the results are as follows: 0 of 5 samples exceeded the water quality standard. CSCI scores were from 0.8225707081 to 0.93919427592 .

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-MC6 (BIO-MC6 East Martis Creek).

Temporal Representation:

Samples were collected from 2010-09-10 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


DECISION ID	162682	Region 6
East Martis Creek

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 162682, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 6
East Martis Creek

LOE ID:

338795

Pollutant:

Nitrate/Nitrite (Nitrite + Nitrate as N)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Truckee River Watershed Council data for East Martis Creek to determine beneficial use support and results are as follows: 0 of 6 samples exceeded the water quality threshold for Nitrate + Nitrite as N.

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Watershed Council 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: MTREMAR (East Martis Creek at bridge).

Temporal Representation:

The samples were collected between the dates of 2017-05-20 and 2020-10-03

Environmental Conditions:

QAPP Information:

QAPP for Truckee River Monitoring Plan

QAPP Information Reference(s):

Quality Assurance Project Plan (QAPP) for Truckee River Monitoring Plan.

Line of Evidence (LOE) for Decision ID 162682, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 6
East Martis Creek

LOE ID:

338842

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 East Martis Creek 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:

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-MC2 (DST-MC2 East Martis Creek downstream of concrete bridge).

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	169573	Region 6
East Martis Creek

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 169573, Nitrogen	Region 6
East Martis Creek

LOE ID:

347821

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 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-MC2 East Martis Creek downstream of concrete bridge (DST-MC2)

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 169573, Nitrogen	Region 6
East Martis Creek

LOE ID:

347828

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-MC2 East Martis Creek downstream of concrete bridge (DST-MC2)

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	169404	Region 6
East Martis Creek

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 169404, Nitrogen, Nitrate	Region 6
East Martis Creek

LOE ID:

347749

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-MC2 East Martis Creek downstream of concrete bridge (DST-MC2)

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 169404, Nitrogen, Nitrate	Region 6
East Martis Creek

LOE ID:

347756

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-MC2 East Martis Creek downstream of concrete bridge (DST-MC2)

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	162683	Region 6
East Martis Creek

Pollutant:	Oxygen, Dissolved
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
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. Seven lines of evidence are available in the administrative record to assess this parameter: 5 which assess dissolved oxygen concentration data and 2 which assess dissolved oxygen percent saturation data. Four of 61 samples are below the objective for minimum dissolved oxygen concentration. Two of 17 samples are 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. Four of 61 samples are below the objective for minimum dissolved oxygen concentration. Two of 17 samples are 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 162683, Oxygen, Dissolved	Region 6
East Martis Creek

LOE ID:

347719

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:

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 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-MC6 East Martis Creek (BIO-MC6)

Temporal Representation:

The samples were collected between the dates of 2010-09-10 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 162683, Oxygen, Dissolved	Region 6
East Martis Creek

LOE ID:

347718

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:

Water Board staff assessed Truckee River Watershed Council data to determine beneficial use support and results are as follows:
2 of 14 samples fell below the minimum water quality threshold for Oxygen, Dissolved

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Watershed Council 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: East Martis Creek at bridge (MTREMAR)

Temporal Representation:

The samples were collected between the dates of 2017-05-20 and 2020-10-03

Environmental Conditions:

QAPP Information:

QAPP for Truckee River Monitoring Plan

QAPP Information Reference(s):

Quality Assurance Project Plan (QAPP) for Truckee River Monitoring Plan.

Line of Evidence (LOE) for Decision ID 162683, Oxygen, Dissolved	Region 6
East Martis Creek

LOE ID:

129963

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:

Water Board staff assessed Truckee River Watershed Council data for East Martis Creek to determine beneficial use support and results are as follows: 0 of 23 samples exceeded the water quality standard for Oxygen, Dissolved.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for the Truckee River Watershed Council.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

For waters with the beneficial uses of COLD, COLD with SPWN, WARM, and WARM with SPWN, the minimum dissolved oxygen concentration shall not be less than that specified in Table 3-6. (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(s) (MTREMAR)

Temporal Representation:

The samples were collected between the dates of 2011-06-17 and 2016-09-24

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan (QAPP) for Truckee River Monitoring Plan.

QAPP Information Reference(s):

Quality Assurance Project Plan (QAPP) for Truckee River Monitoring Plan.

Line of Evidence (LOE) for Decision ID 162683, Oxygen, Dissolved	Region 6
East Martis Creek

LOE ID:

351214

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-MC6 East Martis Creek (BIO-MC6)

Temporal Representation:

The samples were collected between the dates of 2010-09-10 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 162683, Oxygen, Dissolved	Region 6
East Martis Creek

LOE ID:

351232

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 Watershed Council data to determine beneficial use support and results are as follows:
2 of 12 samples fell below the minimum water quality threshold for Oxygen, Dissolved

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Watershed Council 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: East Martis Creek at bridge (MTREMAR)

Temporal Representation:

The samples were collected between the dates of 2017-05-20 and 2020-10-03

Environmental Conditions:

QAPP Information:

QAPP for Truckee River Monitoring Plan

QAPP Information Reference(s):

Quality Assurance Project Plan (QAPP) for Truckee River Monitoring Plan.

Line of Evidence (LOE) for Decision ID 162683, Oxygen, Dissolved	Region 6
East Martis Creek

LOE ID:

351338

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-MC6 East Martis Creek (BIO-MC6)

Temporal Representation:

The samples were collected between the dates of 2010-09-10 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 162683, Oxygen, Dissolved	Region 6
East Martis Creek

LOE ID:

351353

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 Watershed Council 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: East Martis Creek at bridge (MTREMAR)

Temporal Representation:

The samples were collected between the dates of 2017-05-20 and 2020-10-03

Environmental Conditions:

QAPP Information:

QAPP for Truckee River Monitoring Plan

QAPP Information Reference(s):

Quality Assurance Project Plan (QAPP) for Truckee River Monitoring Plan.


DECISION ID	168663	Region 6
East Martis Creek

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 168663, Specific Conductivity	Region 6
East Martis Creek

LOE ID:

340566

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-MC6 (BIO-MC6 East Martis Creek).

Temporal Representation:

The samples were collected between the dates of 2010-09-10 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 168663, Specific Conductivity	Region 6
East Martis Creek

LOE ID:

340485

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:

Water Board staff assessed Truckee River Watershed Council data for East Martis Creek to determine beneficial use support and results are as follows: 0 of 13 samples exceeded the water quality threshold for SpecificConductivity.

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Watershed Council 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: MTREMAR (East Martis Creek at bridge).

Temporal Representation:

The samples were collected between the dates of 2017-05-20 and 2020-10-03

Environmental Conditions:

QAPP Information:

QAPP for Truckee River Monitoring Plan

QAPP Information Reference(s):

Quality Assurance Project Plan (QAPP) for Truckee River Monitoring Plan.


DECISION ID	169154	Region 6
East Martis Creek

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

Regional Board Conclusion:	This pollutant is being considered for placement on the 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. One of the fourteen samples exceed the 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. One of fourteen samples exceeded the objective, and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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 169154, Total Kjeldahl Nitrogen (TKN)	Region 6
East Martis Creek

LOE ID:

348017

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-MC2 East Martis Creek downstream of concrete bridge (DST-MC2)

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 169154, Total Kjeldahl Nitrogen (TKN)	Region 6
East Martis Creek

LOE ID:

348012

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 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-MC2 East Martis Creek downstream of concrete bridge (DST-MC2)

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 169154, Total Kjeldahl Nitrogen (TKN)	Region 6
East Martis Creek

LOE ID:

348030

Pollutant:

Total Kjeldahl Nitrogen (TKN)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Truckee River Watershed Council data to determine beneficial use support and results are as follows:
0 of 4 samples exceeded the water quality threshold for Nitrogen, Total Kjeldahl

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Watershed Council 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: East Martis Creek at bridge (MTREMAR)

Temporal Representation:

The samples were collected between the dates of 2017-05-20 and 2020-10-03

Environmental Conditions:

QAPP Information:

QAPP for Truckee River Monitoring Plan

QAPP Information Reference(s):

Quality Assurance Project Plan (QAPP) for Truckee River Monitoring Plan.


DECISION ID	162684	Region 6
East Martis Creek

Pollutant:	pH
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
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 162684, pH	Region 6
East Martis Creek

LOE ID:

129622

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:

0 of 0 samples exceeded the water quality standard for pH. Although pH data does exist for this waterbody, the objective for this pollutant requires background information that is currently unavailable, and therefore an assessment of water quality standards could not be made.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for the Truckee River Watershed Council.

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(s) (MTREMAR)

Temporal Representation:

The samples were collected between the dates of 2011-06-17 and 2016-09-24

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan (QAPP) for Truckee River Monitoring Plan.

QAPP Information Reference(s):

Quality Assurance Project Plan (QAPP) for Truckee River Monitoring Plan.

Line of Evidence (LOE) for Decision ID 162684, pH	Region 6
East Martis Creek

LOE ID:

339987

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 Watershed Council data for East Martis Creek to determine beneficial use support and results are as follows: 0 of 9 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 Watershed Council 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: MTREMAR (East Martis Creek at bridge).

Temporal Representation:

The samples were collected between the dates of 2017-09-23 and 2020-10-03

Environmental Conditions:

QAPP Information:

QAPP for Truckee River Monitoring Plan

QAPP Information Reference(s):

Quality Assurance Project Plan (QAPP) for Truckee River Monitoring Plan.

Line of Evidence (LOE) for Decision ID 162684, pH	Region 6
East Martis Creek

LOE ID:

339745

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 Watershed Council 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: MTREMAR (East Martis Creek at bridge).

Temporal Representation:

The samples were collected between the dates of 2017-09-23 and 2020-10-03

Environmental Conditions:

QAPP Information:

QAPP for Truckee River Monitoring Plan

QAPP Information Reference(s):

Quality Assurance Project Plan (QAPP) for Truckee River Monitoring Plan.

Line of Evidence (LOE) for Decision ID 162684, pH	Region 6
East Martis Creek

LOE ID:

129553

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:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for the Truckee River Watershed Council.

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(s) (MTREMAR)

Temporal Representation:

The samples were collected between the dates of 2011-06-17 and 2016-09-24

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan (QAPP) for Truckee River Monitoring Plan.

QAPP Information Reference(s):

Quality Assurance Project Plan (QAPP) for Truckee River Monitoring Plan.

Line of Evidence (LOE) for Decision ID 162684, pH	Region 6
East Martis Creek

LOE ID:

340069

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 East Martis Creek 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:

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-MC6 (BIO-MC6 East Martis Creek).

Temporal Representation:

The samples were collected between the dates of 2010-09-10 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 162684, pH	Region 6
East Martis Creek

LOE ID:

339866

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-MC6 (BIO-MC6 East Martis Creek).

Temporal Representation:

The samples were collected between the dates of 2010-09-10 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


DECISION ID	169010	Region 6
East Martis Creek

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. Five lines of evidence are available in the administrative record to assess this pollutant. 6 of 10 total phosphorus 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. 6 of 10 total phosphorus samples exceeded 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 169010, Phosphorus	Region 6
East Martis Creek

LOE ID:

347892

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:
0 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-MC2 East Martis Creek downstream of concrete bridge (DST-MC2)

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 169010, Phosphorus	Region 6
East Martis Creek

LOE ID:

347899

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-MC2 East Martis Creek downstream of concrete bridge (DST-MC2)

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 169010, Phosphorus	Region 6
East Martis Creek

LOE ID:

347903

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-MC2 East Martis Creek downstream of concrete bridge (DST-MC2)

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 169010, Phosphorus	Region 6
East Martis Creek

LOE ID:

347916

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 Watershed Council data to determine beneficial use support and results are as follows:
0 of 4 samples exceeded the water quality threshold for Phosphorus as P

Data Reference:

Benthic, Field, Habitat, WQ from the Truckee River Watershed Council 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: East Martis Creek at bridge (MTREMAR)

Temporal Representation:

The samples were collected between the dates of 2017-05-20 and 2020-10-03

Environmental Conditions:

QAPP Information:

QAPP for Truckee River Monitoring Plan

QAPP Information Reference(s):

Quality Assurance Project Plan (QAPP) for Truckee River Monitoring Plan.

Line of Evidence (LOE) for Decision ID 169010, Phosphorus	Region 6
East Martis Creek

LOE ID:

347890

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 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-MC2 East Martis Creek downstream of concrete bridge (DST-MC2)

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	163818	Region 6
East Martis Creek

Pollutant:	Turbidity
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
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. Six lines of evidence are available in the administrative record to assess this pollutant. 28 of the 28 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. Twenty-eight of 28 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 163818, Turbidity	Region 6
East Martis Creek

LOE ID:

347998

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-MC2 East Martis Creek downstream of concrete bridge (DST-MC2)

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 163818, Turbidity	Region 6
East Martis Creek

LOE ID:

347996

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:
6 of 6 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-MC2 East Martis Creek downstream of concrete bridge (DST-MC2)

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 163818, Turbidity	Region 6
East Martis Creek

LOE ID:

343490

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-MC2 East Martis Creek downstream of concrete bridge (DST-MC2)

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 163818, Turbidity	Region 6
East Martis Creek

LOE ID:

343463

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 Watershed Council 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 Watershed Council 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: East Martis Creek at bridge (MTREMAR)

Temporal Representation:

The samples were collected between the dates of 2017-05-20 and 2020-10-03

Environmental Conditions:

QAPP Information:

QAPP for Truckee River Monitoring Plan

QAPP Information Reference(s):

Quality Assurance Project Plan (QAPP) for Truckee River Monitoring Plan.

Line of Evidence (LOE) for Decision ID 163818, Turbidity	Region 6
East Martis Creek

LOE ID:

347997

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 Watershed Council 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 Watershed Council 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: East Martis Creek at bridge (MTREMAR)

Temporal Representation:

The samples were collected between the dates of 2017-05-20 and 2020-10-03

Environmental Conditions:

QAPP Information:

QAPP for Truckee River Monitoring Plan

QAPP Information Reference(s):

Quality Assurance Project Plan (QAPP) for Truckee River Monitoring Plan.

Line of Evidence (LOE) for Decision ID 163818, Turbidity	Region 6
East Martis Creek

LOE ID:

343497

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-MC2 East Martis Creek downstream of concrete bridge (DST-MC2)

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