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

Supporting Information

Regional Board 1 - North Coast Region

Water Body Name:	Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed
Water Body ID:	CAR1141101320081204231407
Water Body Type:	River & Stream


DECISION ID	156748	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

Pollutant:	Oxygen, Dissolved
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 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 removal from the CWA section 303(d) List under section 4.2 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. Twenty-five lines of evidence are available in the administrative record to assess this pollutant. ***COLD FRESHWATER HABITAT BENEFICIAL USE* DO NOT LIST** For ATASCADERO CREEK, there are nine lines of evidence (LOEs 317796, 317797, 317801, 317802, 317806, 317810, 317814, 317818, 317822) and 22 of the 293 samples exceed the objective, and this does not exceed the allowable frequency in Table 3.2 of the Listing Policy. For JONIVE CREEK, there are three lines of evidence (LOEs 318162, 318166, 318170) and 0 of 17 samples exceed the objective, and this is insufficient data to apply Table 3.2 of the Listing Policy. For REDWOOD CREEK, there is one line of evidence (LOE 318437) and 0 of 5 samples exceed the objective, and this is insufficient data to apply Table 3.2 of the Listing Policy. For UNNAMED TRIBUTARY AT MONTGOMERY ROAD, there is one line of evidence (LOE 319021) and 0 of the 5 samples exceed the objective, and this is insufficient data to apply Table 3.2 of the Listing Policy. LIST For LAKE GRATON, there is one line of evidence (LOE 318237) and 129 of 133 samples exceed the objective, and this exceeds the allowable frequency of Table 3.2 of the Listing Policy. DO NOT DELIST* *For GREEN VALLEY CREEK, there are ten lines of evidence (LOEs 101279, 101308, 101309, 101310, 129888, 129889, 318112, 318143, 318449, 318850) and 33 of the 96 samples exceed the objective, and this exceeds the allowable frequency in Table 4.2 of the Listing Policy. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from 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. For Green Valley Creek, 33 of 96 samples exceed the objective and this exceeds the allowable frequency listed in Table 4.2 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met. This listing applies to Green Valley Creek and Lake Graton. This listing applies to Green Valley Creek and Lake Graton.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:	This listing applies to Green Valley Creek and Lake Graton.

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 156748, Oxygen, Dissolved	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

318162

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed the dissolved oxygen data and determined that 0 of 2 samples exceed the May-September minimum of 6 mg/L and 0 of 1 sample exceeds the October-April minimum of 9 mg/L, so that 0 of 3 samples exceed the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Basin, Chapter III, General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states: Dissolved oxygen concentrations shall conform to those limits listed in Section 3.3.5. Section 3.3.5 lists dissolved oxygen concentration limits for COLD beneficial use waters to be a daily minimum of 6.0 mg/L and a 7-day moving minimum average of 8.0 mg/L and dissolved oxygen concentration limits for SPWN beneficial use waters to be a daily minimum of 9.0 mg/L and a 7-day moving average of 11.0 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at sampling station name: Jonive Creek @ Ferguson Road xing; station code: JOC-20.

Temporal Representation:

These samples were collected on 5/18/2020-12/17/2020.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156748, Oxygen, Dissolved	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

318850

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed dissolved oxygen data for USGS California Water Science Center and determined that 0 of 1 sample is less than the May-September minimum of 6.0 mg/L and 0 of 4 samples are less than the October-April minimum of 9.0 mg/L, so that 0 of 5 samples exceed the water quality objective.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at sampling station name: GREEN VALLEY C A GRATON CA; station code: USGS-382619122531401.

Temporal Representation:

These samples were collected from 4/5/2017-5/3/2017.

Environmental Conditions:

QAPP Information:

QAPP for USGS California Water Science Center

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 156748, Oxygen, Dissolved	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

101309

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total 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 the data for this water body to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for dissolved oxygen. Data range from 7.6 mg/L.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) Green Valley Creek above Highway 116 (114GV3469).

Temporal Representation:

The samples were collected between the dates of 7/5/2011.

Environmental Conditions:

There are no known environmental conditions (e.g., seasonality, land use practices, fire events, storms, etc.) that are related to these data.

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156748, Oxygen, Dissolved	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

129888

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total 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:

Eleven out of 35 daily minimum dissolved oxygen (DO) samples exceeded the minimum DO water quality objective. This LOE is a copy of LOE 26094 from the 2012 Integrated Report. The data was reassessed based on new minimum thresholds for DO.

Data Reference:

Community Clean Water Institute Master Data for 2005. Downloaded from http://ccwi.org/issues/data.htm on August 25, 2008

Community Clean Water Institute Master Data for 2006. Downloaded from http://ccwi.org/issues/data.htm on August 25, 2008

A History of the Salmonid Decline in the Russian River.

Map of Historical Salmonid Streams and Calwater 2.2a Hydrologic Sub-Areas. California Department of Fish and Game, Central Coast Region. IHRMP North Coast GIS Lab. Hopland, CA

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Basin, Chapter III, General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states: Dissolved oxygen concentrations shall conform to those limits listed in Section 3.3.5. Section 3.3.5 lists dissolved oxygen concentration limits for SPAWN beneficial use waters to be a daily minimum of 6.0 mg/L and a 7-day moving average of 8.0 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 7 sites along the entire mainstem of Green Valley Creek: from Harrison Grade and Green Valley Road to the Russian River confluence.

Temporal Representation:

The DO samples were collected from July 2005 to September 2006. The DO samples were collected as instantaneous values and do not represent diurnal conditions.

Environmental Conditions:

There are no known environmental conditions (e.g., seasonality, land use practices, fire events, storms, etc.) that are related to these data.

QAPP Information:

Samples were collected in accordance with the "Community Clean Water Institute Volunteer Water Quality Monitoring Program Sampling and Analysis Methods" (CCWI 2007).

QAPP Information Reference(s):

Community Clean Water Institute Volunteer Water Quality Monitoring Program Sampling and Analysis Methods. Updated April 12, 2007

Line of Evidence (LOE) for Decision ID 156748, Oxygen, Dissolved	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

101308

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total 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:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) Green Valley Creek above Atascadero Creek (114GV5331).

Temporal Representation:

The samples were collected between the dates of 7/6/2011.

Environmental Conditions:

There are no known environmental conditions (e.g., seasonality, land use practices, fire events, storms, etc.) that are related to these data.

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156748, Oxygen, Dissolved	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

101279

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total Dissolved

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed the data for this water body to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality standard for dissolved oxygen. Data range from 7.1 mg/L.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Basin, Chapter III, General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states: Dissolved oxygen concentrations shall conform to those limits listed in Section 3.3.5. Section 3.3.5 lists dissolved oxygen concentration limits for SPAWN beneficial use waters to be a daily minimum of 9.0 mg/L and a 7-day moving average of 11.0 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) Green Valley Creek at Martinelli Road (114GV2455).

Temporal Representation:

The samples were collected between the dates of 10/6/2011.

Environmental Conditions:

There are no known environmental conditions (e.g., seasonality, land use practices, fire events, storms, etc.) that are related to these data.

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156748, Oxygen, Dissolved	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

101310

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total 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 the data for this water body to determine beneficial use support and results are as follows: 6 of 17 samples exceeded the water quality standard for dissolved oxygen. Data range from 1.8 - 8.6 mg/L.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) Green Valley Creek at Martinelli Road (114GV2455).

Temporal Representation:

The samples were collected between the dates of 5/26/2011 - 9/29/2011.

Environmental Conditions:

There are no known environmental conditions (e.g., seasonality, land use practices, fire events, storms, etc.) that are related to these data.

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156748, Oxygen, Dissolved	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

129889

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total Dissolved

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Ten out of 21 daily minimum dissolved oxygen (DO) samples exceeded the minimum DO water quality objective. This LOE is a copy of LOE 26094 from the 2012 Integrated Report. The data was reassessed based on new minimum thresholds for DO.

Data Reference:

Community Clean Water Institute Master Data for 2005. Downloaded from http://ccwi.org/issues/data.htm on August 25, 2008

Community Clean Water Institute Master Data for 2006. Downloaded from http://ccwi.org/issues/data.htm on August 25, 2008

A History of the Salmonid Decline in the Russian River.

Map of Historical Salmonid Streams and Calwater 2.2a Hydrologic Sub-Areas. California Department of Fish and Game, Central Coast Region. IHRMP North Coast GIS Lab. Hopland, CA

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Basin, Chapter III, General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states: Dissolved oxygen concentrations shall conform to those limits listed in Section 3.3.5. Section 3.3.5 lists dissolved oxygen concentration limits for SPAWN beneficial use waters to be a daily minimum of 9.0 mg/L and a 7-day moving average of 11.0 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 7 sites along the entire mainstem of Green Valley Creek: from Harrison Grade and Green Valley Road to the Russian River confluence.

Temporal Representation:

The DO samples were collected from October 2005 to December 2006. The DO samples were collected as instantaneous values and do not represent diurnal conditions.

Environmental Conditions:

There are no known environmental conditions (e.g., seasonality, land use practices, fire events, storms, etc.) that are related to these data.

QAPP Information:

Samples were collected in accordance with the "Community Clean Water Institute Volunteer Water Quality Monitoring Program Sampling and Analysis Methods" (CCWI 2007).

QAPP Information Reference(s):

Community Clean Water Institute Volunteer Water Quality Monitoring Program Sampling and Analysis Methods. Updated April 12, 2007

Line of Evidence (LOE) for Decision ID 156748, Oxygen, Dissolved	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

26094

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total Dissolved

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Seventeen of the 77 samples collected in Green Valley Creek exceeded the minimum DO water quality objective. Data were divided into two categories, 1) no spawning, incubation, and emergence occurring and 2) spawning, incubation, and emergence occurring. Presence and absence of salmonid species was determined by utilizing CDFG map (Brooks 2002). Timing of spawning, incubation, and emergence was determined utilizing Steiner Environmental Consulting (1996).

The DO values when no spawning, incubation, and emergence were occurring ranged from 2.3 mg/L to 11.3 mg/L (11 exceedences of the objective). DO values during times of spawning, incubation, and emergence ranged from 7.1 mg/L to 13.1 mg/L (6 exceedences of the objective).

These samples were collected by the Community Clean Water Institute¿s Volunteer Water Quality Monitoring Program (CCWI 2006, and CCWI 2007).

Data Reference:

Map of Historical Salmonid Streams and Calwater 2.2a Hydrologic Sub-Areas. California Department of Fish and Game, Central Coast Region. IHRMP North Coast GIS Lab. Hopland, CA

A History of the Salmonid Decline in the Russian River.

Community Clean Water Institute Master Data for 2005. Downloaded from http://ccwi.org/issues/data.htm on August 25, 2008

Community Clean Water Institute Master Data for 2006. Downloaded from http://ccwi.org/issues/data.htm on August 25, 2008

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Per the Basin Plan (NCRWQCB 2007): (1) Dissolved oxygen concentrations for waters not listed in Table 3-1, and where dissolved oxygen objectives are not prescribed, shall not be reduced below 6.0 mg/L for waters designated as COLD.
(2) Dissolved oxygen concentrations for waters not listed in Table 3-1, and where dissolved oxygen objectives are not prescribed, shall not be reduced below 9.0 mg/L for waters designated as SPWN during critical spawning and egg incubation periods.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - North Coast Region (Region 1)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 7 sites along the entire mainstem of Green Valley Creek: from Harrison Grade and Green Valley Road to the Russian River confluence.

Temporal Representation:

The DO samples were collected from July 2005 to December 2006. The DO samples were collected as instantaneous values and do not represent diurnal conditions.

Environmental Conditions:

There are no known environmental conditions (e.g., seasonality, land use practices, fire events, storms, etc.) that are related to these data.

QAPP Information:

Samples were collected in accordance with the "Community Clean Water Institute Volunteer Water Quality Monitoring Program Sampling and Analysis Methods" (CCWI 2007).

QAPP Information Reference(s):

Community Clean Water Institute Volunteer Water Quality Monitoring Program Sampling and Analysis Methods. Updated April 12, 2007

Line of Evidence (LOE) for Decision ID 156748, Oxygen, Dissolved	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

318437

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed dissolved data for Proposition 1 Grant for Gold Ridge RCD and determined that 0 of 0 samples were less than the May-September minimum of 6.0 mg/L and 0 of 5 samples were less than the October-April minimum of 9.0 mg/L, so that 0 of 5 samples exceed the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected from sampling station name: Redwood Creek @ Furlong Road xing; station code: REC-20.

Temporal Representation:

These samples were collected from 1/9/2019-3/18/2021.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156748, Oxygen, Dissolved	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

318237

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Fish Spawning

Number of Samples:

133

Number of Exceedances:

129

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed dissolved oxygen data for Proposition 1 Grant for Gold Ridge RCD and determined that 129 of 133 daily averages and 138 of 141 rolling 7 day averages exceed the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at sampling station name: Lake Graton inside southeast berm; station code: LKG-10.

Temporal Representation:

These samples were collected from 1/10/2019-6/5/2019.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156748, Oxygen, Dissolved	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

318170

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed the dissolved oxygen data and determined that 0 of 3 samples exceed the May-September minimum of 6 mg/L and 0 of 8 samples exceed the October-April minimum of 9 mg/L, so that 0 of 11 samples exceed the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at sampling station name: Jonive Creek @ Sexton Road xing; station code: JOC-40.

Temporal Representation:

These samples were collected from 11/29/2018-3/28/2021.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156748, Oxygen, Dissolved	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

318166

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed the dissolved oxygen data and determined that 0 of 0 samples exceed the May-September minimum of 6 mg/L and 0 of 3 samples exceed the October-April minimum of 9 mg/L, so that 0 of 3 samples exceed the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at sampling station name: Jonive Creek @ Furlong Road xing; station code: JOC-50.

Temporal Representation:

These samples were collected from 11/29/2018-2/26/2019.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156748, Oxygen, Dissolved	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

317810

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 data from parent project Proposition 1 Grant for Gold Ridge RCD and determined that 2 of 10 samples exceed the Water Quality Objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at station name: Atascadero @ Watertrough Road xing; station code: ATC-60.

Temporal Representation:

These samples were collected from 11/29/2018-3/18/2021.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156748, Oxygen, Dissolved	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

317814

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

239

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed data from parent project Proposition 1 Grant for Gold Ridge RCD and determined that 6 of 64 samples exceed the 1-day and 0 of 46 samples exceed the 7-day average water quality objective from May-September and 2 of 175 samples exceed the 1-day and 0 of 151 samples exceed the 7-day average water quality objective for October-April.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at station name: Atascadero Creek @ Atascadero Creek Ecological Reserve southwest/Atascadero Creek frontage berm; station code: ATC-08.

Temporal Representation:

These samples were collected from 1/29/2019-6/4/2020.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156748, Oxygen, Dissolved	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

317796

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 dissolved oxygen data from parent project Proposition 1 Grant for Gold Ridge RCD and determined that 0 of the 1 sample exceeds the Water Quality Objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at station name: Atascadero @ Barnett Valley Road xing; station code: ATC-80

Temporal Representation:

This sample was collected on 2/26/2019.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156748, Oxygen, Dissolved	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

317818

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 data from parent project Proposition 1 Grant for Gold Ridge RCD and determined that 1 of 5 samples exceed the dissolved oxygen water quality objective for May-September and 5 of 8 samples exceed the dissolved oxygen water quality objective for October-April, so that 6 of 13 samples exceeded the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at station name: Atascadero Creek @ Graton Road xing; station code: ATC-20.

Temporal Representation:

These samples were collected from 11/29/2018-3/18/2021.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156748, Oxygen, Dissolved	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

317802

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed data from parent project Proposition 1 Grant for Gold Ridge RCD and determined that 0 of the 10 samples exceed the Water Quality Objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at station name: Atascadero @ Mill Station Road xing; station code: ATC-40

Temporal Representation:

These samples were collected from 2/26/2019-3/18/2021

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156748, Oxygen, Dissolved	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

317806

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 data from parent project Proposition 1 Grant for Gold Ridge RCD and determined that 2 of 9 sample exceeds the Water Quality Objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at station name: Atascadero @ Occidental Road xing; station code: ATC-30.

Temporal Representation:

These samples were collected from 1/9/2019-3/18/2021.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156748, Oxygen, Dissolved	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

317822

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 data from parent project Proposition 1 Grant for Gold Ridge RCD and determined that 1 of 6 samples exceed the dissolved oxygen water quality objective for May-September and 1 of 6 samples exceed the dissolved oxygen water quality objective for October-April, so that 2 of 12 samples exceeded the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at station name: Atascadero Creek @ Graton Road xing; station code: ATC-20.

Temporal Representation:

These samples were collected from 1/9/2019-3/19/2021.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156748, Oxygen, Dissolved	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

317797

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed dissolved oxygen data from parent project Proposition 1 Grant for Gold Ridge RCD and determined that 0 of the 1 sample exceeds the Water Quality Objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at station name: Atascadero @ Barnett Valley Road xing; station code: ATC-80

Temporal Representation:

This sample was collected on 2/26/2019.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156748, Oxygen, Dissolved	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

318112

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed the data and determined that 0 of 3 samples exceed the May-September minimum of 6.0 mg/L and 1/ of 3 samples exceed the October-April minimum of 9.0 mg/L, so that 1 of 6 samples exceed the water quality objective for dissolved oxygen.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at sampling station name: Green Valley Creek at Green Valley Road crossing (lower); station code: GVC-60.

Temporal Representation:

These samples were collected from 5/14/2019-3/18/2021.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156748, Oxygen, Dissolved	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

318143

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed the dissolved oxygen data and determined that 0 of 0 samples exceed the May-September minimum of 6 mg/L and 0 of 1 sample exceeds the October-April minimum of 9 mg/L, so that 0 of 1 sample exceeds the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

This sample was collected at sampling station name: Hwy 116 crossing over Green Valley Creek; station code: GVC-45.

Temporal Representation:

This sample was collected on 1/16.2020.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156748, Oxygen, Dissolved	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

317801

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 dissolved oxygen data from parent project Proposition 1 Grant for Gold Ridge RCD and determined that 1 of the 2 samples exceed the Water Quality Objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at station name: Atascadero @ Mill Station Road xing; station code: ATC-40

Temporal Representation:

These samples were collected from 2/26/2019-3/18/2021

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156748, Oxygen, Dissolved	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

319021

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed dissolved oxygen data for USGS California Water Science Center and determined that 0 of 1 sample is less than the the May-September minimum of 6.0 mg/L and 0 of 4 samples are less than the October-April minimum of 9.0 mg/L, so that 0 of 5 samples exceed the water quality objective.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at sampling station name: UNNAMED TRIB A MONTGOMERY RD NR SEBASTOPOL CA; station code: USGS-382346122521201.

Temporal Representation:

These samples were collected from 4/5/2017-5/3/2017.

Environmental Conditions:

QAPP Information:

QAPP for USGS California Water Science Center

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 156748, Oxygen, Dissolved	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

318449

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed dissolved oxygen data for QAPP for Proposition 1 Grant for Gold Ridge RCD and determined that 3 of 4 samples were less than the May-September minimum of 6.0 mg/L and 1 of 4 samples were less than the October-April minimum of 9.0 mg/L, so that 4 of 8 samples exceed the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at sampling station name: Ross Station Road crossing over Green Valley Creek; station code: GVC-50.

Temporal Representation:

These samples were collected from 5/14/2019-3/18/2021.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679


DECISION ID	103995	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status. Two line(s) of evidence are available in the administrative record to assess this pollutant. None of the 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. 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. None samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 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:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 103995, Alkalinity as CaCO3	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

101819

Pollutant:

Alkalinity as CaCO3

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Monitoring data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for Alkalinity as CaCO3.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

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 (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 103995, Alkalinity as CaCO3	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

101817

Pollutant:

Alkalinity as CaCO3

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	102620	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3 of the Listing Policy. Under section 3 a single line of evidence are necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the 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. 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. None of the samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 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:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 102620, Aluminum	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

101820

Pollutant:

Aluminum

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15. The secondary maximum contaminant level listed in Table 64449-A for Aluminum is 0.2 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 102620, Aluminum	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

101821

Pollutant:

Aluminum

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	161424	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

Pollutant:	Ammonia
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 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. 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.

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 161424, Ammonia	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

323307

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm 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 Proposition 1 Grant for Gold Ridge RCD data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Ammonia as N.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for AmmoniaNAFreshwater 2013 document.

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: JOC-40 (Jonive Creek @ Sexton Road xing).

Temporal Representation:

The samples were collected between the dates of 2019-01-16 and 2021-03-18

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 161424, Ammonia	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

323521

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:

Water Board staff assessed Proposition 1 Grant for Gold Ridge RCD data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: ATC-80 (Atascadero @ Barnett Valley Road xing).

Temporal Representation:

The samples were collected between the dates of 2019-02-26 and 2019-02-26

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 161424, Ammonia	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

323518

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm 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 Proposition 1 Grant for Gold Ridge RCD data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ammonia as N.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: ATC-10 (Atascadero Creek @ Green Valley Road xing).

Temporal Representation:

The samples were collected between the dates of 2019-01-16 and 2021-03-18

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 161424, Ammonia	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

323403

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:

Water Board staff assessed Proposition 1 Grant for Gold Ridge RCD data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ammonia as N.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: ATC-40 (Atascadero @ Mill Station Road xing).

Temporal Representation:

The samples were collected between the dates of 2019-01-16 and 2021-03-18

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 161424, Ammonia	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

323402

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm 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 Proposition 1 Grant for Gold Ridge RCD data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: ATC-30 (Atascadero @ Occidental Road xing).

Temporal Representation:

The samples were collected between the dates of 2021-03-18 and 2021-03-18

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 161424, Ammonia	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

323401

Pollutant:

Nitrogen, ammonia (Total Ammonia)

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 Proposition 1 Grant for Gold Ridge RCD data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Health Advisory for lifetime exposure to Ammonia as a drinking water level is a concentration of 30 mg/L

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site: ATC-30 (Atascadero @ Occidental Road xing).

Temporal Representation:

The samples were collected between the dates of 2021-03-18 and 2021-03-18

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 161424, Ammonia	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

323290

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:

Water Board staff assessed Proposition 1 Grant for Gold Ridge RCD data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: ATC-30 (Atascadero @ Occidental Road xing).

Temporal Representation:

The samples were collected between the dates of 2021-03-18 and 2021-03-18

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 161424, Ammonia	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

323396

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:

Water Board staff assessed Proposition 1 Grant for Gold Ridge RCD data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: ATC-20 (Atascadero Creek @ Graton Road xing).

Temporal Representation:

The samples were collected between the dates of 2021-03-18 and 2021-03-18

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 161424, Ammonia	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

323285

Pollutant:

Nitrogen, ammonia (Total Ammonia)

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:

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Health Advisory for lifetime exposure to Ammonia as a drinking water level is a concentration of 30 mg/L

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site: ATC-40 (Atascadero @ Mill Station Road xing).

Temporal Representation:

The samples were collected between the dates of 2019-01-16 and 2021-03-18

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 161424, Ammonia	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

323275

Pollutant:

Nitrogen, ammonia (Total Ammonia)

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 Proposition 1 Grant for Gold Ridge RCD data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Health Advisory for lifetime exposure to Ammonia as a drinking water level is a concentration of 30 mg/L

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site: GVC-50 (Ross Station Road crossing over Green Valley Creek).

Temporal Representation:

The samples were collected between the dates of 2020-01-16 and 2020-01-16

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 161424, Ammonia	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

323483

Pollutant:

Nitrogen, ammonia (Total Ammonia)

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 Proposition 1 Grant for Gold Ridge RCD data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Ammonia as N.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Health Advisory for lifetime exposure to Ammonia as a drinking water level is a concentration of 30 mg/L

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site: JOC-40 (Jonive Creek @ Sexton Road xing).

Temporal Representation:

The samples were collected between the dates of 2019-01-16 and 2021-03-18

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 161424, Ammonia	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

323365

Pollutant:

Nitrogen, ammonia (Total Ammonia)

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 Proposition 1 Grant for Gold Ridge RCD data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Health Advisory for lifetime exposure to Ammonia as a drinking water level is a concentration of 30 mg/L

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site: GVC-45 (Hwy 116 crossing over Green Valley Creek).

Temporal Representation:

The samples were collected between the dates of 2020-01-16 and 2020-01-16

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 161424, Ammonia	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

323451

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm 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 Proposition 1 Grant for Gold Ridge RCD data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ammonia as N.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: ATC-40 (Atascadero @ Mill Station Road xing).

Temporal Representation:

The samples were collected between the dates of 2019-01-16 and 2021-03-18

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 161424, Ammonia	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

323355

Pollutant:

Nitrogen, ammonia (Total Ammonia)

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 Proposition 1 Grant for Gold Ridge RCD data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Health Advisory for lifetime exposure to Ammonia as a drinking water level is a concentration of 30 mg/L

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site: ATC-20 (Atascadero Creek @ Graton Road xing).

Temporal Representation:

The samples were collected between the dates of 2021-03-18 and 2021-03-18

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 161424, Ammonia	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

323308

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm 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 Proposition 1 Grant for Gold Ridge RCD data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: ATC-80 (Atascadero @ Barnett Valley Road xing).

Temporal Representation:

The samples were collected between the dates of 2019-02-26 and 2019-02-26

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 161424, Ammonia	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

323528

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:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: JOC-40 (Jonive Creek @ Sexton Road xing).

Temporal Representation:

The samples were collected between the dates of 2019-01-16 and 2021-03-18

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 161424, Ammonia	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

323562

Pollutant:

Nitrogen, ammonia (Total Ammonia)

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 Proposition 1 Grant for Gold Ridge RCD data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Ammonia as N.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Health Advisory for lifetime exposure to Ammonia as a drinking water level is a concentration of 30 mg/L

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site: ATC-60 (Atascadero @ Watertrough Road xing).

Temporal Representation:

The samples were collected between the dates of 2019-01-16 and 2021-03-18

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 161424, Ammonia	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

323316

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm 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 Proposition 1 Grant for Gold Ridge RCD data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: ATC-20 (Atascadero Creek @ Graton Road xing).

Temporal Representation:

The samples were collected between the dates of 2021-03-18 and 2021-03-18

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 161424, Ammonia	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

323532

Pollutant:

Nitrogen, ammonia (Total Ammonia)

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 Proposition 1 Grant for Gold Ridge RCD data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Health Advisory for lifetime exposure to Ammonia as a drinking water level is a concentration of 30 mg/L

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site: REC-20 (Redwood Creek @ Furlong Road xing).

Temporal Representation:

The samples were collected between the dates of 2020-01-16 and 2020-01-16

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 161424, Ammonia	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

323557

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: ATC-60 (Atascadero @ Watertrough Road xing).

Temporal Representation:

The samples were collected between the dates of 2019-01-16 and 2021-03-18

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 161424, Ammonia	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

323334

Pollutant:

Nitrogen, ammonia (Total Ammonia)

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 Proposition 1 Grant for Gold Ridge RCD data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Health Advisory for lifetime exposure to Ammonia as a drinking water level is a concentration of 30 mg/L

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site: ATC-80 (Atascadero @ Barnett Valley Road xing).

Temporal Representation:

The samples were collected between the dates of 2019-02-26 and 2019-02-26

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 161424, Ammonia	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

323555

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:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: ATC-60 (Atascadero @ Watertrough Road xing).

Temporal Representation:

The samples were collected between the dates of 2019-01-16 and 2021-03-18

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 161424, Ammonia	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

323550

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:

Water Board staff assessed Proposition 1 Grant for Gold Ridge RCD data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ammonia as N.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: ATC-10 (Atascadero Creek @ Green Valley Road xing).

Temporal Representation:

The samples were collected between the dates of 2019-01-16 and 2021-03-18

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 161424, Ammonia	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

323549

Pollutant:

Nitrogen, ammonia (Total Ammonia)

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:

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Health Advisory for lifetime exposure to Ammonia as a drinking water level is a concentration of 30 mg/L

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site: ATC-10 (Atascadero Creek @ Green Valley Road xing).

Temporal Representation:

The samples were collected between the dates of 2019-01-16 and 2021-03-18

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 161424, Ammonia	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

101824

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

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 SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161424, Ammonia	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

101825

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Health Advisory for lifetime exposure to Ammonia as a drinking water level is a concentration of 30 mg/L

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161424, Ammonia	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

101823

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Health Advisory for lifetime exposure to Ammonia as a drinking water level is a concentration of 30 mg/L

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161424, Ammonia	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

101822

Pollutant:

Nitrogen, ammonia (Total Ammonia)

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:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161424, Ammonia	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

26086

Pollutant:

Ammonia as Nitrogen

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

None of the 5 total ammonia as nitrogen instantaneous grab samples collected from the Green Valley Creek Watershed exceed the evaluation guideline. The sample concentrations range from non-detect to 0.51 mg/l. The samples were collected as part of the Russian River First Flush sampling event. Data are summarized by Katznelson et al. (2003).

Data Reference:

2002 Russian River First Flush Summary Report. Clean Water Team, Citizen Monitoring Program of the State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Per the Basin Plan (NCRWQCB 2007): "Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses."

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - North Coast Region (Region 1)

Evaluation Guideline:

Per the National Recommended Water Quality Criteria (USEPA 2006): The 1-hour average concentration (acute criterion or CMC) of total ammonia nitrogen (in mg N/L) for freshwater where salmonid fish are present, which is not to be exceeded more than once every three years on average, is calculated using the following equation: CMC=0.275/(1+10^(7.204 - pH)) + 39.0/(1+10^(pH - 7.204)).

Guideline Reference:

Spatial Representation:

The samples were collected from 5 sites in the Green Valley Creek Watershed as follows: (1) in Green Valley Creek at Martinelli Road; (2) in Atascadero Creek at the Green Valley Road bridge; (3) in Graton Gulch at Railroad Avenue; (4) in Atascadero Creek at Mill Station Road; and (5) in Atascadero Creek at Bodega Highway.

Temporal Representation:

The samples were collected on November 7, 2002. At each site, 1 to 3 instantaneous grab samples were collected over half hour increments. The data are averaged for each site where multiple samples were collected.

Environmental Conditions:

Samples were collected during the first runoff event of the rainy season.

QAPP Information:

Samples were collected in accordance with the study plan and quality control procedures described by Katznelson et al. (2003).

QAPP Information Reference(s):

2002 Russian River First Flush Summary Report. Clean Water Team, Citizen Monitoring Program of the State Water Resources Control Board


DECISION ID	100790	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

Pollutant:	Arsenic
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(s) of evidence are necessary to assess listing status. Eight lines of evidence are available in the administrative record to assess this pollutant. None of the 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. 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. None of the samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 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:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 100790, Arsenic	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

101830

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

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 SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The dissolved arsenic criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater for dissolved arsenic is 150 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 100790, Arsenic	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

101834

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

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 SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The dissolved arsenic criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater for dissolved arsenic is 150 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 100790, Arsenic	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

101833

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15. The maximum contaminant level listed in Table 64431-A for arsenic is 0.010 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 100790, Arsenic	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

101828

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15. The maximum contaminant level listed in Table 64431-A for arsenic is 0.010 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 100790, Arsenic	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

101831

Pollutant:

Arsenic

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:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The dissolved arsenic criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater for dissolved arsenic is 150 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 100790, Arsenic	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

101826

Pollutant:

Arsenic

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:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The dissolved arsenic criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater for dissolved arsenic is 150 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	158524	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

Pollutant:	Azoxystrobin
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 158524, Azoxystrobin	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328036

Pollutant:

Azoxystrobin

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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Azoxystrobin.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Azoxystrobin is the USEPA Aquatic Life Benchmark of 44 ug/L for an invertebrate (chronic).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382619122531401 (GREEN VALLEY C A GRATON CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-19 and 2017-05-03

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158524, Azoxystrobin	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328032

Pollutant:

Azoxystrobin

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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Azoxystrobin.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Azoxystrobin is the USEPA Aquatic Life Benchmark of 44 ug/L for an invertebrate (chronic).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382346122521201 (UNNAMED TRIB A MONTGOMERY RD NR SEBASTOPOL CA).

Temporal Representation:

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

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158524, Azoxystrobin	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328034

Pollutant:

Azoxystrobin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm 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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Azoxystrobin.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Azoxystrobin is the USEPA Aquatic Life Benchmark of 44 ug/L for an invertebrate (chronic).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382346122521201 (UNNAMED TRIB A MONTGOMERY RD NR SEBASTOPOL CA).

Temporal Representation:

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

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158524, Azoxystrobin	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328030

Pollutant:

Azoxystrobin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Azoxystrobin is the USEPA Aquatic Life Benchmark of 44 ug/L for an invertebrate (chronic).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382619122531401 (GREEN VALLEY C A GRATON CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-19 and 2017-05-03

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle


DECISION ID	104857	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

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 is being considered for placement on the CWA section 303(d) List under sections 3.9 of the Listing Policy. Under section 3.9, an additional line of evidence associating the Benthic Community Effects with a water or sediment concentration of pollutants is necessary to assess listing status. Three lines of evidence are available in the administrative record to assess this indicator. All three CSCI scores in this water body meet the evaluation guideline which indicates that beneficial uses are supported in this water body. 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 water 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. All three CSCI scores in this water body meet the evaluation guideline which indicates that beneficial uses are supported in this water body.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 104857, Benthic Community Effects	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

96477

Pollutant:

Benthic-Macroinvertebrate Bioassessments

LOE Subgroup:

Population/Community Degradation

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Benthic macroinvertebrate surveys

Data Used to Assess Water Quality:

The site had a CSCI score(s) of 0.810888311, 0.970454138 & 0.955981841.

The samples taken on 7/6/11 were averaged to 0.963217989.

These scores indicate that this site is supporting the aquatic life beneficial use and that the water quality objective has been met.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

Water Quality Objective/Criterion:

From the Water Quality Control Plan, North Coast Region: 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.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

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:

These samples were collected at the following station:
114GV3469
114GV5331

Temporal Representation:

These samples were collected on: 7/5/2011 & 7/6/2011

Environmental Conditions:

QAPP Information:

Data collected following SWAMP QA protocols.

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	101724	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status. Six lines of evidence are available in the administrative record to assess this pollutant. None of the 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. 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. None of the samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 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:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 101724, Cadmium	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

101843

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15. The maximum contaminant level listed in Table 64431-A for cadmium 0.005 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 101724, Cadmium	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

101835

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

California Toxics Rule (CTR) lists criterion continuous concentrations to protect aquatic life in freshwater. The criterion in freshwater is hardness dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 101724, Cadmium	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

108084

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 101724, Cadmium	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

108087

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

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 SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 101724, Cadmium	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

108083

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

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 SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 101724, Cadmium	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

108088

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15. The maximum contaminant level listed in Table 64431-A for cadmium 0.005 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	158515	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

Pollutant:	Chloride
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:	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 158515, Chloride	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328125

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm 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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Chloride.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382619122531401 (GREEN VALLEY C A GRATON CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-05 and 2017-05-03

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158515, Chloride	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328162

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm 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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Chloride.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382346122521201 (UNNAMED TRIB A MONTGOMERY RD NR SEBASTOPOL CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-05 and 2017-05-03

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158515, Chloride	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328119

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Chloride.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382619122531401 (GREEN VALLEY C A GRATON CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-05 and 2017-05-03

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158515, Chloride	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328187

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Chloride.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382346122521201 (UNNAMED TRIB A MONTGOMERY RD NR SEBASTOPOL CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-05 and 2017-05-03

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158515, Chloride	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

101845

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158515, Chloride	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

101844

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	100824	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

Pollutant:	Chromium
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(s) of evidence are necessary to assess listing status. Two line(s) of evidence are available in the administrative record to assess this pollutant. Zero of the 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. 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. None of the samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 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:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 100824, Chromium	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

108092

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15. The maximum contaminant level listed in Table 64431-A for chromium 0.05 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 100824, Chromium	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

108093

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15. The maximum contaminant level listed in Table 64431-A for chromium 0.05 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	100779	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status. Six lines of evidence are available in the administrative record to assess this pollutant. None of the 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. 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 two samples exceeded the objective for the COLD, WARM, and MUN beneficial uses and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.4. 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:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 100779, Copper	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

101856

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 100779, Copper	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

101855

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 100779, Copper	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

101854

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

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 SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 100779, Copper	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

101850

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

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 SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 100779, Copper	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

108094

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 100779, Copper	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

101852

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	158516	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

Pollutant:	Glyphosate
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 158516, Glyphosate	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328383

Pollutant:

Glyphosate

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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Glyphosate.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15. The maximum contaminant level listed in Table 64444-A for glyphosate is 700 ug/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382619122531401 (GREEN VALLEY C A GRATON CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-12 and 2017-04-12

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158516, Glyphosate	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328371

Pollutant:

Glyphosate

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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Glyphosate.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15. The maximum contaminant level listed in Table 64444-A for glyphosate is 700 ug/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382346122521201 (UNNAMED TRIB A MONTGOMERY RD NR SEBASTOPOL CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-12 and 2017-04-12

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158516, Glyphosate	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328389

Pollutant:

Glyphosate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm 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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Glyphosate.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Glyphosate is the USEPA Aquatic Life Benchmark of 11900 ug/L for a vascular plant (acute).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382619122531401 (GREEN VALLEY C A GRATON CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-12 and 2017-04-12

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158516, Glyphosate	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328368

Pollutant:

Glyphosate

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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Glyphosate.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Glyphosate is the USEPA Aquatic Life Benchmark of 11900 ug/L for a vascular plant (acute).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382619122531401 (GREEN VALLEY C A GRATON CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-12 and 2017-04-12

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158516, Glyphosate	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328377

Pollutant:

Glyphosate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm 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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Glyphosate.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Glyphosate is the USEPA Aquatic Life Benchmark of 11900 ug/L for a vascular plant (acute).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382346122521201 (UNNAMED TRIB A MONTGOMERY RD NR SEBASTOPOL CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-12 and 2017-04-12

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158516, Glyphosate	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328385

Pollutant:

Glyphosate

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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Glyphosate.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Glyphosate is the USEPA Aquatic Life Benchmark of 11900 ug/L for a vascular plant (acute).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382346122521201 (UNNAMED TRIB A MONTGOMERY RD NR SEBASTOPOL CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-12 and 2017-04-12

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle


DECISION ID	158514	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

Pollutant:	Hydroxyatrazine, 2-
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

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

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 158514, Hydroxyatrazine, 2-	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328401

Pollutant:

Hydroxyatrazine, 2-

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm 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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Hydroxyatrazine, 2-.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for hydroxyatrazine, 2- is the USEPA Aquatic Life Benchmark of 1,500 ug/L for a fish (acute) for triazine HA degradate.

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382346122521201 (UNNAMED TRIB A MONTGOMERY RD NR SEBASTOPOL CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-19 and 2017-04-19

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158514, Hydroxyatrazine, 2-	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328397

Pollutant:

Hydroxyatrazine, 2-

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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Hydroxyatrazine, 2-.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for hydroxyatrazine, 2- is the USEPA Aquatic Life Benchmark of 1,500 ug/L for a fish (acute) for triazine HA degradate.

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382346122521201 (UNNAMED TRIB A MONTGOMERY RD NR SEBASTOPOL CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-19 and 2017-04-19

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle


DECISION ID	104884	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

Pollutant:	Lead
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(s) of evidence are necessary to assess listing status. Six lines of evidence are available in the administrative record to assess this pollutant. None of the 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. 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. None of the two samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 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:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 104884, Lead	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

101859

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

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 SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 104884, Lead	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

119993

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Waters designated for MUN shall not contain concentrations of chemical constituents in excess of values listed in Table 3-2 of the Basin Plan. The value for lead is 0.05 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 104884, Lead	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

119992

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

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 SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 104884, Lead	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

101860

Pollutant:

Lead

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:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 104884, Lead	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

101857

Pollutant:

Lead

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:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 104884, Lead	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

119994

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	103756	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

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

Regional Board Conclusion:	This pollutant is being considered for placement on the 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. Two lines of evidence are available in the administrative record to assess this pollutant. One of the two samples exceed the objecive. 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. One of two samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 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:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 103756, Manganese	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

119996

Pollutant:

Manganese

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 103756, Manganese	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

119995

Pollutant:

Manganese

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 SWAMP RWB1 Monitoring data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality standard for Manganese.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	161352	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

Pollutant:	Mercury
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:	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 161352, Mercury	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

120003

Pollutant:

Mercury

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:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

National Recommended Water Quality Criteria Continuous Concentrations (4-day average concentrations) for freshwater aquatic organisms exposure to total mercury is 0.77 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161352, Mercury	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328503

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm 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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Mercury.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Waters shall not contain toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. (Basin Plan, 2018)

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

National Recommended Water Quality Criteria Continuous Concentrations (4-day average concentrations) for freshwater aquatic organisms exposure to total mercury is 0.77 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382619122531401 (GREEN VALLEY C A GRATON CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-12 and 2017-04-26

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 161352, Mercury	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328491

Pollutant:

Mercury

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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Mercury.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Waters shall not contain toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. (Basin Plan, 2018)

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

National Recommended Water Quality Criteria Continuous Concentrations (4-day average concentrations) for freshwater aquatic organisms exposure to total mercury is 0.77 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382619122531401 (GREEN VALLEY C A GRATON CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-12 and 2017-04-26

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 161352, Mercury	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328511

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Mercury.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): 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. The established numeric criteria for mercury to protect of human health from the consumption of organisms only is 0.051 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382346122521201 (UNNAMED TRIB A MONTGOMERY RD NR SEBASTOPOL CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-12 and 2017-04-27

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 161352, Mercury	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328513

Pollutant:

Mercury

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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Mercury.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): 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. The established numeric criteria for mercury to protect of human health from the consumption of water and organisms is 0.050 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382619122531401 (GREEN VALLEY C A GRATON CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-12 and 2017-04-26

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 161352, Mercury	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328519

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm 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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Mercury.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Waters shall not contain toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. (Basin Plan, 2018)

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

National Recommended Water Quality Criteria Continuous Concentrations (4-day average concentrations) for freshwater aquatic organisms exposure to total mercury is 0.77 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382346122521201 (UNNAMED TRIB A MONTGOMERY RD NR SEBASTOPOL CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-12 and 2017-04-27

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 161352, Mercury	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328521

Pollutant:

Mercury

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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Mercury.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Waters shall not contain toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. (Basin Plan, 2018)

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

National Recommended Water Quality Criteria Continuous Concentrations (4-day average concentrations) for freshwater aquatic organisms exposure to total mercury is 0.77 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382346122521201 (UNNAMED TRIB A MONTGOMERY RD NR SEBASTOPOL CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-12 and 2017-04-27

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 161352, Mercury	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328485

Pollutant:

Mercury

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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Mercury.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): 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. The established numeric criteria for mercury to protect of human health from the consumption of water and organisms is 0.050 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382346122521201 (UNNAMED TRIB A MONTGOMERY RD NR SEBASTOPOL CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-12 and 2017-04-27

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 161352, Mercury	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

119998

Pollutant:

Mercury

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:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

National Recommended Water Quality Criteria Continuous Concentrations (4-day average concentrations) for freshwater aquatic organisms exposure to total mercury is 0.77 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161352, Mercury	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328509

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Mercury.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382619122531401 (GREEN VALLEY C A GRATON CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-12 and 2017-04-26

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 161352, Mercury	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

119997

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

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 SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161352, Mercury	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

120001

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

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 SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161352, Mercury	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

120005

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): 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. The established numeric criteria for mercury to protect of human health from the consumption of water and organisms is 0.050 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161352, Mercury	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

120000

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): 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. The established numeric criteria for mercury to protect of human health from the consumption of water and organisms is 0.050 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	158525	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

Pollutant:	Methoxyfenozide
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 158525, Methoxyfenozide	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328539

Pollutant:

Methoxyfenozide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm 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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Methoxyfenozide.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for methoxyfenozide is the USEPA Aquatic Life Benchmark of 3.1 ug/L for an invertebrate (chronic).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382346122521201 (UNNAMED TRIB A MONTGOMERY RD NR SEBASTOPOL CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-05 and 2017-05-03

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158525, Methoxyfenozide	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328545

Pollutant:

Methoxyfenozide

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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Methoxyfenozide.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for methoxyfenozide is the USEPA Aquatic Life Benchmark of 3.1 ug/L for an invertebrate (chronic).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382346122521201 (UNNAMED TRIB A MONTGOMERY RD NR SEBASTOPOL CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-05 and 2017-05-03

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158525, Methoxyfenozide	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328542

Pollutant:

Methoxyfenozide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for methoxyfenozide is the USEPA Aquatic Life Benchmark of 3.1 ug/L for an invertebrate (chronic).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382619122531401 (GREEN VALLEY C A GRATON CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-05 and 2017-04-19

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158525, Methoxyfenozide	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328537

Pollutant:

Methoxyfenozide

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:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for methoxyfenozide is the USEPA Aquatic Life Benchmark of 3.1 ug/L for an invertebrate (chronic).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382619122531401 (GREEN VALLEY C A GRATON CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-05 and 2017-04-19

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle


DECISION ID	158523	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

Pollutant:	Myclobutanil
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 158523, Myclobutanil	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328583

Pollutant:

Myclobutanil

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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Myclobutanil.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for myclobutanil is the USEPA Aquatic Life Benchmark of 122 ug/L for nonvascular plants.

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382346122521201 (UNNAMED TRIB A MONTGOMERY RD NR SEBASTOPOL CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-27 and 2017-04-27

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158523, Myclobutanil	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328587

Pollutant:

Myclobutanil

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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Myclobutanil.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for myclobutanil is the USEPA Aquatic Life Benchmark of 122 ug/L for nonvascular plants.

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382619122531401 (GREEN VALLEY C A GRATON CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-19 and 2017-04-19

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158523, Myclobutanil	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328588

Pollutant:

Myclobutanil

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm 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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Myclobutanil.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for myclobutanil is the USEPA Aquatic Life Benchmark of 122 ug/L for nonvascular plants.

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382619122531401 (GREEN VALLEY C A GRATON CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-19 and 2017-04-19

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158523, Myclobutanil	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328585

Pollutant:

Myclobutanil

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm 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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Myclobutanil.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for myclobutanil is the USEPA Aquatic Life Benchmark of 122 ug/L for nonvascular plants.

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382346122521201 (UNNAMED TRIB A MONTGOMERY RD NR SEBASTOPOL CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-27 and 2017-04-27

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle


DECISION ID	101128	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

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

Regional Board Conclusion:	This pollutant is being considered for placement on the 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. None of the 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. 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 2 sample exceed the objective for each of the COLD, WARM, COMM and MUN beneficial uses and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 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:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 101128, Nickel	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

120011

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

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 SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 101128, Nickel	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

120008

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

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 SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 101128, Nickel	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

120012

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

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 SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): 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. The established numeric criteria for Nickel to protect human health from consumption of organisms only is 4600 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 101128, Nickel	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

120015

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

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 SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): 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. The established numeric criteria for Nickel to protect human health from consumption of organisms only is 4600 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 101128, Nickel	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

120016

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15. The maximum contaminant level listed in Table 64431-A for nickel is 0.1 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 101128, Nickel	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

120014

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15. The maximum contaminant level listed in Table 64431-A for nickel is 0.1 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 101128, Nickel	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

120009

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 101128, Nickel	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

120006

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	74514	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

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

Regional Board Conclusion:	This pollutant is being considered for placement on the Section 303(d) List under Section 3.1 of the Listing Policy. Under Section 3.1, a single line of evidence is necessary to assess listing status. Six lines of evidence are available in the administrative record to assess this pollutant. It should be noted that LOE 26088 from the 2010 Integrated Report was not used in this decision, and the data are re-evaluated in LOEs 47205, 47206, and 47207. None of the samples exceeded the objective for the MUN beneficial use. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the Section 303(d) List in the Water Quality Limited Segments category (i.e., sufficient justification to not 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) None of the samples exceed the water quality objective for MUN, and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. (4) Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 74514, Nitrate	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

120017

Pollutant:

Nitrogen, Nitrate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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 SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for nitrate (NO3 as N) incorporated by reference in the Water Quality Control Plan, North Coast Basin is 10.0 mg/L (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 74514, Nitrate	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

47205

Pollutant:

Nitrate

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:

Zero of 1 nitrate as nitrogen sample collected in Green Valley Creek exceeds the objective. The sample was collected as part of the Russian River First Flush sampling event. Data are summarized by Katznelson et al. (2003). This LOE and LOEs 47206 and 47207 replace LOE 26088 from the 2010 Integrated Report cycle. The data have been re-evaluated against an updated MCL and data for each stream have been separated into their own LOE.

Data Reference:

2002 Russian River First Flush Summary Report. Clean Water Team, Citizen Monitoring Program of the State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (2011): Waters designated for MUN shall not contain concentrations of chemical constituents in excess of the MCL specified in Title 22 of the California Code of Regulations. The nitrate (as N) MCL is 10 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The sample was collected from Green Valley Creek at Martinelli Road.

Temporal Representation:

The sample was collected on November 7, 2002.

Environmental Conditions:

Samples were collected during the first runoff event of the rainy season.

QAPP Information:

Samples were collected in accordance with the study plan and quality control procedures described by Katznelson et al. (2003).

QAPP Information Reference(s):

2002 Russian River First Flush Summary Report. Clean Water Team, Citizen Monitoring Program of the State Water Resources Control Board

Line of Evidence (LOE) for Decision ID 74514, Nitrate	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

26092

Pollutant:

Nitrate

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:

None of the 60 nitrate as nitrogen samples collected in Green Valley Creek exceeded the objective. The sample concentrations range from non-detect (detection limits of 0.02 mg/L - 0.04 mg/L) to 0.64 mg/L. These samples were collected by the Community Clean Water Institute¿s Volunteer Water Quality Monitoring Program (CCWI 2006, CCWI 2007).

Data Reference:

Community Clean Water Institute Master Data for 2005. Downloaded from http://ccwi.org/issues/data.htm on August 25, 2008

Community Clean Water Institute Master Data for 2006. Downloaded from http://ccwi.org/issues/data.htm on August 25, 2008

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Per the Basin Plan (NCRWQCB 2007): The water quality objective for nitrate as nitrogen is 45 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - North Coast Region (Region 1)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 7 sites along the entire mainstem of Green Valley Creek: from Harrison Grade and Green Valley Rd. to the Russian River confluence.

Temporal Representation:

The samples were collected from July 2005 to December 2006.

Environmental Conditions:

There are no known environmental conditions (e.g., seasonality, land use practices, fire events, storms, etc.) that are related to these data.

QAPP Information:

Samples were collected in accordance with the "Community Clean Water Institute Volunteer Water Quality Monitoring Program Sampling and Analysis Methods" (CCWI 2007). At each site a grab sample was collected using a container on a pole or by a bucket attached to a rope. The samples were then put into sterilized Whirl Pak bags, put into coolers on ice, and brought to the lab for analysis.

QAPP Information Reference(s):

Community Clean Water Institute Volunteer Water Quality Monitoring Program Sampling and Analysis Methods. Updated April 12, 2007

Line of Evidence (LOE) for Decision ID 74514, Nitrate	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

47207

Pollutant:

Nitrate

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:

Zero of 1 nitrate as nitrogen sample collected in Atascadero Creek exceeds the objective. The sample was collected as part of the Russian River First Flush sampling event. Data are summarized by Katznelson et al. (2003). This LOE and LOEs 47205 and 47206 replace LOE 26088 from the 2010 Integrated Report cycle. The data have been re-evaluated against an updated MCL and data for each stream have been separated into their own LOE.

Data Reference:

2002 Russian River First Flush Summary Report. Clean Water Team, Citizen Monitoring Program of the State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The sample was collected from Atascadero Creek at Bodega Highway.

Temporal Representation:

The sample was collected on November 7, 2002.

Environmental Conditions:

Samples were collected during the first runoff event of the rainy season.

QAPP Information:

Samples were collected in accordance with the study plan and quality control procedures described by Katznelson et al. (2003).

QAPP Information Reference(s):

2002 Russian River First Flush Summary Report. Clean Water Team, Citizen Monitoring Program of the State Water Resources Control Board

Line of Evidence (LOE) for Decision ID 74514, Nitrate	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

120018

Pollutant:

Nitrogen, Nitrate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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 SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 74514, Nitrate	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

26088

Pollutant:

Nitrate

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:

None of the 3 nitrate as nitrogen samples collected in the Green Valley Creek Watershed exceed the objective. The sample concentrations range from 0.2 to 0.5. The samples were collected as part of the Russian River First Flush sampling event. Data are summarized by Katznelson et al. (2003).

Data Reference:

2002 Russian River First Flush Summary Report. Clean Water Team, Citizen Monitoring Program of the State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Per the Basin Plan (NCRWQCB 2007): The water quality objective for nitrate as nitrogen is 45 mg/l.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - North Coast Region (Region 1)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected from 3 sites in the Green Valley Creek Watershed as follows: (1) in Green Valley Creek at Martinelli Road; (2) in Graton Gulch at Railroad Avenue; and (3) in Atascadero Creek at Bodega Highway.

Temporal Representation:

Environmental Conditions:

Samples were collected during the first runoff event of the rainy season.

QAPP Information:

Samples were collected in accordance with the study plan and quality control procedures described by Katznelson et al. (2003).

QAPP Information Reference(s):

2002 Russian River First Flush Summary Report. Clean Water Team, Citizen Monitoring Program of the State Water Resources Control Board

Line of Evidence (LOE) for Decision ID 74514, Nitrate	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

47206

Pollutant:

Nitrate

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:

Zero of 1 nitrate as nitrogen sample collected in Graton Gulch exceeds the objective. The sample was collected as part of the Russian River First Flush sampling event. Data are summarized by Katznelson et al. (2003). This LOE and LOEs 47205 and 47207 replace LOE 26088 from the 2010 Integrated Report cycle. The data have been re-evaluated against an updated MCL and data for each stream have been separated into their own LOE.

Data Reference:

2002 Russian River First Flush Summary Report. Clean Water Team, Citizen Monitoring Program of the State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The sample was collected from Graton Gulch at Railroad Avenue.

Temporal Representation:

The sample was collected on November 7, 2002.

Environmental Conditions:

Samples were collected during the first runoff event of the rainy season.

QAPP Information:

Samples were collected in accordance with the study plan and quality control procedures described by Katznelson et al. (2003).

QAPP Information Reference(s):

2002 Russian River First Flush Summary Report. Clean Water Team, Citizen Monitoring Program of the State Water Resources Control Board


DECISION ID	158517	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

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 158517, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328642

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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed 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:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

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, North Coast Basin is 10.0 mg/L (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382346122521201 (UNNAMED TRIB A MONTGOMERY RD NR SEBASTOPOL CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-05 and 2017-05-03

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158517, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328646

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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Nitrate + Nitrite as N.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382619122531401 (GREEN VALLEY C A GRATON CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-05 and 2017-05-03

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle


DECISION ID	161380	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

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:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. 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.

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 161380, Nitrogen, Nitrate	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328672

Pollutant:

Nitrogen, Nitrate

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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed 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:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382346122521201 (UNNAMED TRIB A MONTGOMERY RD NR SEBASTOPOL CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-05 and 2017-05-03

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 161380, Nitrogen, Nitrate	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328687

Pollutant:

Nitrogen, Nitrate

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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Nitrate as N.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382619122531401 (GREEN VALLEY C A GRATON CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-05 and 2017-05-03

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 161380, Nitrogen, Nitrate	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

325857

Pollutant:

Nitrogen, Nitrate

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 Proposition 1 Grant for Gold Ridge RCD data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Nitrate as N.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: ATC-20 (Atascadero Creek @ Graton Road xing).

Temporal Representation:

The samples were collected between the dates of 2019-02-26 and 2021-03-18

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 161380, Nitrogen, Nitrate	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

325950

Pollutant:

Nitrogen, Nitrate

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 Proposition 1 Grant for Gold Ridge RCD data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Nitrate as N.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: ATC-80 (Atascadero @ Barnett Valley Road xing).

Temporal Representation:

The samples were collected between the dates of 2019-02-26 and 2019-02-26

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 161380, Nitrogen, Nitrate	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

325933

Pollutant:

Nitrogen, Nitrate

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 Proposition 1 Grant for Gold Ridge RCD data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed 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:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: ATC-60 (Atascadero @ Watertrough Road xing).

Temporal Representation:

The samples were collected between the dates of 2019-01-16 and 2021-03-18

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 161380, Nitrogen, Nitrate	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

325911

Pollutant:

Nitrogen, Nitrate

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 Proposition 1 Grant for Gold Ridge RCD data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Nitrate as N.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: ATC-10 (Atascadero Creek @ Green Valley Road xing).

Temporal Representation:

The samples were collected between the dates of 2019-01-16 and 2020-01-16

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 161380, Nitrogen, Nitrate	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

325906

Pollutant:

Nitrogen, Nitrate

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 Proposition 1 Grant for Gold Ridge RCD data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed 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:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: JOC-40 (Jonive Creek @ Sexton Road xing).

Temporal Representation:

The samples were collected between the dates of 2019-01-16 and 2021-03-18

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 161380, Nitrogen, Nitrate	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

325882

Pollutant:

Nitrogen, Nitrate

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 Proposition 1 Grant for Gold Ridge RCD data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed 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:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: ATC-40 (Atascadero @ Mill Station Road xing).

Temporal Representation:

The samples were collected between the dates of 2019-01-16 and 2021-03-18

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 161380, Nitrogen, Nitrate	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

325866

Pollutant:

Nitrogen, Nitrate

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 Proposition 1 Grant for Gold Ridge RCD data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Nitrate as N.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: GVC-50 (Ross Station Road crossing over Green Valley Creek).

Temporal Representation:

The samples were collected between the dates of 2020-01-16 and 2020-01-16

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 161380, Nitrogen, Nitrate	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

325865

Pollutant:

Nitrogen, Nitrate

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 Proposition 1 Grant for Gold Ridge RCD data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Nitrate as N.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: GVC-45 (Hwy 116 crossing over Green Valley Creek).

Temporal Representation:

The samples were collected between the dates of 2020-01-16 and 2020-01-16

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 161380, Nitrogen, Nitrate	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

325940

Pollutant:

Nitrogen, Nitrate

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 Proposition 1 Grant for Gold Ridge RCD data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Nitrate as N.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: REC-20 (Redwood Creek @ Furlong Road xing).

Temporal Representation:

The samples were collected between the dates of 2020-01-16 and 2021-03-18

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 161380, Nitrogen, Nitrate	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328696

Pollutant:

Nitrate as Nitrate (NO3)

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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Nitrate as NO3.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for nitrate (as NO3) incorporated by reference in the Water Quality Control Plan, North Coast Basin is 45.0 mg/L (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382346122521201 (UNNAMED TRIB A MONTGOMERY RD NR SEBASTOPOL CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-05 and 2017-05-03

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 161380, Nitrogen, Nitrate	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328698

Pollutant:

Nitrate as Nitrate (NO3)

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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Nitrate as NO3.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382619122531401 (GREEN VALLEY C A GRATON CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-05 and 2017-05-03

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle


DECISION ID	161461	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

Pollutant:	Nitrogen, Nitrite
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:	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 161461, Nitrogen, Nitrite	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

108137

Pollutant:

Nitrogen, Nitrite

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:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15. The maximum contaminant level listed in Table 64431-A for Nitrite as N is 1.0 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161461, Nitrogen, Nitrite	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

108138

Pollutant:

Nitrogen, Nitrite

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:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15. The maximum contaminant level listed in Table 64431-A for Nitrite as N is 1.0 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161461, Nitrogen, Nitrite	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328749

Pollutant:

Nitrogen, Nitrite

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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Nitrite as N.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15. The maximum contaminant level listed in Table 64431-A for Nitrite as N is 1.0 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382619122531401 (GREEN VALLEY C A GRATON CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-12 and 2017-04-12

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 161461, Nitrogen, Nitrite	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328748

Pollutant:

Nitrogen, Nitrite

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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Nitrite as N.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15. The maximum contaminant level listed in Table 64431-A for Nitrite as N is 1.0 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382346122521201 (UNNAMED TRIB A MONTGOMERY RD NR SEBASTOPOL CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-05 and 2017-05-03

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle


DECISION ID	104885	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

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

Regional Board Conclusion:	"This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status. Four lines of evidence are available in the administrative record to assess this pollutant. None of the 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. 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. None of the two samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 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:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 104885, Selenium	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

120023

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15. The maximum contaminant level listed in Table 64431-A for selenium is 0.05 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 104885, Selenium	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

120028

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15. The maximum contaminant level listed in Table 64431-A for selenium is 0.05 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 104885, Selenium	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

120026

Pollutant:

Selenium

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:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): 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. The established numeric selenium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 5 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 104885, Selenium	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

120021

Pollutant:

Selenium

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:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): 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. The established numeric selenium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 5 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	103924	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

Pollutant:	Silver
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(s) of evidence are necessary to assess listing status. Six lines of evidence are available in the administrative record to assess this pollutant. None of the 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. 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. None samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 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:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 103924, Silver	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

120032

Pollutant:

Silver

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:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

California Toxics Rule (CTR) lists criterion maximum concentrations to protect aquatic life in freshwater. The criterion in freshwater is hardness dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 103924, Silver	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

120029

Pollutant:

Silver

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:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 103924, Silver	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

120031

Pollutant:

Silver

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

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 SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 103924, Silver	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

120037

Pollutant:

Silver

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 103924, Silver	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

120035

Pollutant:

Silver

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 103924, Silver	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

120034

Pollutant:

Silver

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

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 SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	158518	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

Pollutant:	Simazine
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 158518, Simazine	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

329017

Pollutant:

Simazine

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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Simazine.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for simazine is the USEPA Aquatic Life Benchmark of 6 ug/L for a nonvascular plant (acute).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382619122531401 (GREEN VALLEY C A GRATON CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-19 and 2017-05-03

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158518, Simazine	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

329011

Pollutant:

Simazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm 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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Simazine.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for simazine is the USEPA Aquatic Life Benchmark of 6 ug/L for a nonvascular plant (acute).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382619122531401 (GREEN VALLEY C A GRATON CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-19 and 2017-05-03

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158518, Simazine	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

329015

Pollutant:

Simazine

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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Simazine.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15. The maximum contaminant level listed in Table 64444-A for simazine is 0.004 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382619122531401 (GREEN VALLEY C A GRATON CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-19 and 2017-05-03

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle


DECISION ID	158519	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

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

Regional Board Conclusion:	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 158519, Sodium	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

329107

Pollutant:

Sodium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Agricultural Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Sodium.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Water Quality for Agriculture, published by the Food and Agriculture Organization of the United Nations in 1985, contains criteria protective of various agricultural uses of water, including irrigation of various types of crops and stock watering. At or below the sodium threshold of 69 mg/L, agricultural uses of water should not be limited.

Guideline Reference:

Water Quality for Agriculture, Food and Agriculture Organization of the United Nations - Irrigation and Drainage Paper No. 29, Rev 1, Rome (1985)

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382619122531401 (GREEN VALLEY C A GRATON CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-05 and 2017-05-03

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158519, Sodium	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

329078

Pollutant:

Sodium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Agricultural Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Sodium.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Water Quality for Agriculture, Food and Agriculture Organization of the United Nations - Irrigation and Drainage Paper No. 29, Rev 1, Rome (1985)

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382346122521201 (UNNAMED TRIB A MONTGOMERY RD NR SEBASTOPOL CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-05 and 2017-05-03

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158519, Sodium	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

329118

Pollutant:

Sodium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Sodium.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Per the Drinking Water Standards and Health Advisories (USEPA 2012), the health advisory for sodium for individuals on a sodium-restricted diet is 20 mg/l.

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382346122521201 (UNNAMED TRIB A MONTGOMERY RD NR SEBASTOPOL CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-05 and 2017-05-03

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158519, Sodium	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

329120

Pollutant:

Sodium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Sodium.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Per the Drinking Water Standards and Health Advisories (USEPA 2012), the health advisory for sodium for individuals on a sodium-restricted diet is 20 mg/l.

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382619122531401 (GREEN VALLEY C A GRATON CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-05 and 2017-05-03

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle


DECISION ID	158520	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

Pollutant:	Sulfates
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:	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 158520, Sulfates	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

329233

Pollutant:

Sulfates

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Sulfate.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382619122531401 (GREEN VALLEY C A GRATON CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-05 and 2017-05-03

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158520, Sulfates	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

120039

Pollutant:

Sulfates

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158520, Sulfates	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

120038

Pollutant:

Sulfates

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158520, Sulfates	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

329205

Pollutant:

Sulfates

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Sulfate.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382346122521201 (UNNAMED TRIB A MONTGOMERY RD NR SEBASTOPOL CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-05 and 2017-05-03

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle


DECISION ID	156750	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

Pollutant:	Temperature, water
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(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. Twenty-two lines of evidence are available in the administrative record to assess this pollutant. Zero of 513 samples exceed the cold freshwater habitat beneficial use 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. 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 513 samples exceeded the objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 156750, Temperature, water	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

317817

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Fish Spawning

Number of Samples:

249

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed data from parent project Proposition 1 Grant for Gold Ridge RCD and determined that 0 of 64 samples exceed the temperature water quality objective for May-September and 0 of 185 samples exceed the temperature water quality objective for October-April. On 2/28/2019 and 4/24/2019, temperature data exceeded the water quality objective, but the daily mean was below the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Basin, Chapter III, General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states: Natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Water Board that such alteration in temperature does not adversely affect beneficial uses. At no time or place shall the temperature of any COLD water be increased more than 5 degrees Fahrenheit (F) above natural receiving water temperature.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

According to Carter (2008) the lethal temperature for spawning, incubation, and emergence life stages are 20 degrees C. The lethal temperatures for adult migration and holding, and juvenile migration and rearing is 24 degrees C.

Guideline Reference:

Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region

Spatial Representation:

These samples were collected at station name: Atascadero Creek @ Atascadero Creek Ecological Reserve southwest/Atascadero Creek frontage berm; station code: ATC-08.

Temporal Representation:

These samples were collected from 1/29/2019-6/4/2020.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156750, Temperature, water	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

318452

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed temperature data for QAPP for Proposition 1 Grant for Gold Ridge RCD and determined that 0 of 4 samples were greater than the May-September maximum of 24 degrees Celcius and 0 of 4 samples were greater than the October-April maximum of 20 degrees Celcius, so that 0 of 8 samples exceed the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at sampling station name: Ross Station Road crossing over Green Valley Creek; station code: GVC-50.

Temporal Representation:

These samples were collected from 5/14/2019-3/18/2021.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156750, Temperature, water	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

319023

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed temperature data for USGS California Water Science Center and determined that 0 of 1 sample is greater than the May-September maximum of 24 degrees Celcius and 0 of 4 samples are greater than the October-April maximum of 20 degrees Celcius, so that 0 of 5 samples exceed the water quality objective.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at sampling station name: UNNAMED TRIB A MONTGOMERY RD NR SEBASTOPOL CA; station code: USGS-382346122521201.

Temporal Representation:

These samples were collected from 4/5/2017-5/3/2017.

Environmental Conditions:

QAPP Information:

QAPP for USGS California Water Science Center

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 156750, Temperature, water	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

318852

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at sampling station name: GREEN VALLEY C A GRATON CA; station code: USGS-382619122531401.

Temporal Representation:

These samples were collected from 4/5/2017-5/3/2017.

Environmental Conditions:

QAPP Information:

QAPP for USGS California Water Science Center

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 156750, Temperature, water	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

317805

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed data from parent project Proposition 1 Grant for Gold Ridge RCD and determined that 0 of 11 samples exceed the Water Quality Objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at Klamath River at station name: Atascadero @ Mill Station Road xing; station code: ATC-40

Temporal Representation:

These samples were collected from 11/29/2018-3/18/2021

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156750, Temperature, water	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

318240

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Fish Spawning

Number of Samples:

133

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed temperature data for Proposition 1 Grant for Gold Ridge RCD and determined that 0 of 2862 samples exceed the May-September maximum of 24 degree Celcius and 0 of 8023 samples exceed the October-April maximum of 20 degrees Celcius, so that 0 of 10885 samples exceed the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at sampling station name: Lake Graton inside southeast berm; station code: LKG-10.

Temporal Representation:

These samples were collected from 1/10/2019-6/5/2019.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156750, Temperature, water	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

318165

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed the temperature data and determined that 0 of 2 samples exceed the May-September maxiumum of 24 degrees Celcius and 0 of 1 sample exceeds the October-April maximum of 20 degrees Celcius, so that 0 of 3 samples exceed the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at sampling station name: Jonive Creek @ Ferguson Road xing; station code: JOC-20.

Temporal Representation:

These samples were collected on 5/18/2020-12/17/2020.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156750, Temperature, water	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

318145

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed the temperature data and determined that 0 of 0 samples exceed the May-September maximum of 24 degrees Celcius and 0 of 1 sample exceeds the October-April maximum of 24 degrees Celcius, so that 0 of 1 sample exceeds the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

This sample was collected at sampling station name: Hwy 116 crossing over Green Valley Creek; station code: GVC-45.

Temporal Representation:

This sample was collected on 1/16.2020.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156750, Temperature, water	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

318173

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed the temperature data and determined that 0 of 3 samples exceed the May-September maximum of 24 degrees Celcius and 0 of 9 samples exceed the October-April maximum of 24 degrees Celcius, so that 0 of 12 samples exceed the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at sampling station name: Jonive Creek @ Sexton Road xing; station code: JOC-40.

Temporal Representation:

These samples were collected from 11/29/2018-3/28/2021.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156750, Temperature, water	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

318169

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed the temperature data and determined that 0 of 0 samples exceed the May-September maximum of 24 degrees Celcius and 0 of 3 samples exceed the October-April maximum of 24 degrees Celcius, so that 0 of 3 samples exceed the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at sampling station name: Jonive Creek @ Furlong Road xing; station code: JOC-50.

Temporal Representation:

These samples were collected from 11/29/2018-2/26/2019.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156750, Temperature, water	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

318115

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed the data and determined that 0 of 3 samples exceed the May-September maximum of 24 degrees Celcius and 0 of 3 samples exceed the October-April maximum of 20 degrees Celcius, so that 0 of 6 samples exceed the water quality objective for temperature.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at sampling station name: Green Valley Creek at Green Valley Road crossing (lower); station code: GVC-60.

Temporal Representation:

These samples were collected from 5/14/2019-3/18/2021.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156750, Temperature, water	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

317825

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed data from parent project Proposition 1 Grant for Gold Ridge RCD and determined that 0 of 6 samples exceed the temperature water quality objective for May-September and 0 of 9 samples exceed the temperature water quality objective for October-April, so that 0 of 15 samples exceed the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at station name: Atascadero Creek @ Graton Road xing; station code: ATC-20.

Temporal Representation:

These samples were collected from 1/9/2019-3/19/2021.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156750, Temperature, water	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

317821

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed data from parent project Proposition 1 Grant for Gold Ridge RCD and determined that 0 of 6 samples exceed the temperature water quality objective for May-September and 0 of 8 samples exceed the temperature water quality objective for October-April, so that 0 of 14 samples exceed the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at station name: Atascadero Creek @ Graton Road xing; station code: ATC-20.

Temporal Representation:

These samples were collected from 11/29/2018-3/18/2021.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156750, Temperature, water	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

318440

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed temperature data for Proposition 1 Grant for Gold Ridge RCD and determined that 0 of 0 samples are greater than the May-September maximum of 24 degrees Celcius and 0 of 5 samples are greater than the October-April maximum of 20 degrees Celcius, so that 0 of 5 samples exceed the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected from sampling station name: Redwood Creek @ Furlong Road xing; station code: REC-20.

Temporal Representation:

These samples were collected from 1/9/2019-3/18/2021.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156750, Temperature, water	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

317809

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed data from parent project Proposition 1 Grant for Gold Ridge RCD and determined that 0 of 4 samples exceed the temperature water quality objective for May-September and 0 of 6 samples exceed the temperature water quality objective for October-April.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at station name: Atascadero @ Occidental Road xing; station code: ATC-30.

Temporal Representation:

These samples were collected from 11/29/2018-3/18/2021.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156750, Temperature, water	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

317813

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed data from parent project Proposition 1 Grant for Gold Ridge RCD and determined that 0 of 2 samples exceed the temperature water quality objective for May-September and 0 of 9 samples exceed the temperature water quality objective for October-April.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at station name: Atascadero @ Watertrough Road xing; station code: ATC-60.

Temporal Representation:

These samples were collected from 11/29/2018-3/18/2021.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156750, Temperature, water	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

101320

Pollutant:

Temperature, water

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 the data for this water body to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for Temperature. Data range from 21.5 degrees C.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP Reference Condition Management Plan .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) Green Valley Creek above Atascadero Creek (114GV5331).

Temporal Representation:

The samples were collected between the dates of 7/6/2011.

Environmental Conditions:

There are no known environmental conditions (e.g., seasonality, land use practices, fire events, storms, etc.) that are related to these data.

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156750, Temperature, water	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

101321

Pollutant:

Temperature, water

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 the data for this water body to determine beneficial use support and results are as follows: 0 of 18 samples exceeded the water quality standard for Temperature. Data range from 13.2 - 18.8 degrees C.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP Reference Condition Management Plan .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) Green Valley Creek at Martinelli Road (114GV2455).

Temporal Representation:

The samples were collected between the dates of 5/26/2011 - 9/29/2011.

Environmental Conditions:

There are no known environmental conditions (e.g., seasonality, land use practices, fire events, storms, etc.) that are related to these data.

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156750, Temperature, water	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

101388

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

The following process is utilized to interpret the narrative temperature objective in the Basin Plan for impairment assessments. Step 1: Determine if temperatures reflect natural conditions. If Yes, then the water body is not considered impaired, if No, then go to Step 2. Step 2: Determine if temperatures adversely affect beneficial uses. If Yes, then the water body is considered impaired, if No , then go to Step 3. Step 3: Determine if temperatures are increased by 5 degrees F. If Yes, then water body is impaired, if No, then water body is not impaired.

Data Reference:

Presentation: Interpreting Temperature Standards in the North Coast Region. North Coast Regional Water Quality Control Board.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Water Board that such alteration in temperature does not adversely affect beneficial uses. At no time or place shall the temperature of any COLD water be increased more than 5 degrees Fahrenheit (F) above natural receiving water temperature.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

EVIDENCE OF ALTERATION OF NATURAL RECEIVING WATER TEMPERATURES (NON-NATURAL TEMPS): The water temperatures of the Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed does not reflect natural conditions as environmental factors that influence water temperature have been anthropogenically altered due to land management practices including roads, grazing, logging and agriculture resulting in reduced riparian cover and increased solar radiation input (Russian Riverkeeper 2012). EVIDENCE OF SALMONID PRESENCE & LIFE CYCLE USE: Steelhead, Chinook and Coho are present in the Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed (Busby et al. 1996, McClary et al. 2018, Moyle et al. 2008, Myers et al. 1998, Obedzinski et al. 2016, Obedzinski et al. 2017). Rearing occurs year round and spawning/incubation/emergence occurs from October through April (Busby et al. 1996, McClary et al. 2018, Moyle et al. 2008, Myers et al. 1998, Obedzinski et al. 2016, Obedzinski et al. 2017). Core rearing is supported throughout the Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed.

Guideline Reference:

Converting Forests to Vineyards

Guideline Reference:

UC Coho Salmon and Steelhead Monitoring Report; Winter 2015/2016.

Guideline Reference:

Status Review of West Coast Steelhead from Washington, Idaho, Oregon, and California

Guideline Reference:

UC Coho Salmon and Steelhead Monitoring Report: Spring 2017

Guideline Reference:

Status Review of Chinook Salmon from Washington, Idaho, Oregon and California

Guideline Reference:

Salmon, Steelhead, and Trout in California: Status of an Emblematic Fauna

Guideline Reference:

UC Coho Salmon and Steelhead Monitoring Report: Summer 2017

Spatial Representation:

Information pertains to the Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed.

Temporal Representation:

Data are reflective of current conditions in this water body.

Environmental Conditions:

QAPP Information:

Information is considered to be of adequate quality for the Integrated Report process.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156750, Temperature, water	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

101130

Pollutant:

Temperature, water

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:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) Green Valley Creek at Martinelli Road (114GV2455).

Temporal Representation:

The samples were collected between the dates of 10/6/2011.

Environmental Conditions:

There are no known environmental conditions (e.g., seasonality, land use practices, fire events, storms, etc.) that are related to these data.

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156750, Temperature, water	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

101158

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Fish Spawning

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 SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) Green Valley Creek at Martinelli Road (114GV2455).

Temporal Representation:

The samples were collected between the dates of 10/6/2011.

Environmental Conditions:

There are no known environmental conditions (e.g., seasonality, land use practices, fire events, storms, etc.) that are related to these data.

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156750, Temperature, water	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

317800

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed temperature data from parent project Proposition 1 Grant for Gold Ridge RCD and determined that 0 of the 1 sample exceeds the Water Quality Objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at station name: Atascadero @ Barnett Valley Road xing; station code: ATC-80

Temporal Representation:

This sample was collected on 2/26/2019.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679


DECISION ID	158522	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

Pollutant:	Trifloxystrobin
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 158522, Trifloxystrobin	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

329335

Pollutant:

Trifloxystrobin

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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Trifloxystrobin.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for trifloxystrobin is the USEPA Aquatic Life Benchmark of 2.76 ug/L for an invertebrate (chronic).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382619122531401 (GREEN VALLEY C A GRATON CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-19 and 2017-05-03

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158522, Trifloxystrobin	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

329336

Pollutant:

Trifloxystrobin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm 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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Trifloxystrobin.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for trifloxystrobin is the USEPA Aquatic Life Benchmark of 2.76 ug/L for an invertebrate (chronic).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382619122531401 (GREEN VALLEY C A GRATON CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-19 and 2017-05-03

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle


DECISION ID	157710	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

Pollutant:	Turbidity
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 157710, Turbidity	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

327316

Pollutant:

Turbidity

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 Proposition 1 Grant for Gold Ridge RCD data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Turbidity.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15, Division 4, Article 4, Section 64435 (Tables 2 and 3), and Section 64444.5 (Table 5), and listed in Table 3-2 of this Plan (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

California Maximum Contaminant Levels (MCLs) apply to ambient surface waters under the Basin Plan's 'Chemical Constituents' objective. The Secondary MCL for turbidity is 5 NTU. Calculation of a numeric objective for other beneficial uses requires comparison with upstream or other background data which may not be available as part of the data used for water quality assessment.

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: ATC-60 (Atascadero @ Watertrough Road xing).

Temporal Representation:

The samples were collected between the dates of 2019-01-16 and 2019-01-16

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 157710, Turbidity	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

327312

Pollutant:

Turbidity

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 Proposition 1 Grant for Gold Ridge RCD data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Turbidity.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

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: JOC-40 (Jonive Creek @ Sexton Road xing).

Temporal Representation:

The samples were collected between the dates of 2019-01-16 and 2019-01-16

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 157710, Turbidity	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

327294

Pollutant:

Turbidity

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 Proposition 1 Grant for Gold Ridge RCD data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Turbidity.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

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: ATC-40 (Atascadero @ Mill Station Road xing).

Temporal Representation:

The samples were collected between the dates of 2019-01-16 and 2019-01-16

Environmental Conditions:

QAPP Information:

Proposition 1 Grant for Gold Ridge RCD QAPP

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679


DECISION ID	100842	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3 of the Listing Policy. Under section 3 a single line of evidence are necessary to assess listing status. Six lines of evidence are available in the administrative record to assess this pollutant. None of the 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. 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. None of the samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 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:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 100842, Zinc	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

120043

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 100842, Zinc	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

120040

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 100842, Zinc	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

120048

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 100842, Zinc	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

120045

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

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 SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV5331)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2011-07-06

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 100842, Zinc	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

120046

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 100842, Zinc	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

120042

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

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 SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (114GV3469)

Temporal Representation:

The samples were collected between the dates of 2011-07-05 and 2011-07-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	158521	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

Pollutant:	Imidacloprid
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. Two lines of evidence are available in the administrative record to assess this pollutant. Three of four samples exceed the Cold Freshwater Habitat and Warm Freshwater Habitat beneficial use objectives. 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. Three of four samples exceed the Cold Freshwater Habitat and Warm Freshwater Habitat beneficial use objectives 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. This listing applies to Jonine Creek. LOEs 328423 and 328408 identify an "unnamed creek" that is named Jonine Creek on topographic maps.

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:	LOEs 328423 and 328408 identify an "unnamed creek" that is named Jonine Creek on topographic maps.

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 158521, Imidacloprid	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328423

Pollutant:

Imidacloprid

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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 3 of 4 samples exceeded the water quality threshold for Imidacloprid.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382346122521201 (UNNAMED TRIB A MONTGOMERY RD NR SEBASTOPOL CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-05 and 2017-05-03

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158521, Imidacloprid	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

328408

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm 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 USGS California Water Science Center data for Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed to determine beneficial use support and results are as follows: 3 of 4 samples exceeded the water quality threshold for Imidacloprid.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-382346122521201 (UNNAMED TRIB A MONTGOMERY RD NR SEBASTOPOL CA).

Temporal Representation:

The samples were collected between the dates of 2017-04-05 and 2017-05-03

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle


DECISION ID	163055	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

Pollutant:	Specific Conductivity
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. Eighteen lines of evidence are available in the administrative record to assess this pollutant. Twelve of 42 samples exceed the Cold Freshwater Habitat beneficial use guideline and 3 of 4 samples exceed the Municipal & Domestic Supply beneficial use guideline. 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. Twelve of 42 samples exceed the Cold Freshwater Habitat beneficial use guideline 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. This listing applies to Atascadero Creek. ***COLD FRESHWATER HABITAT BENEFICIAL USE: ATASCADERO CREEK has seven lines of evidence (LOEs 317799, 317804, 317808, 317812, 317816, 317820, 317824) and 11 of 23 samples exceed the guideline, which exceeds the allowable frequency in Table 3.2 of the Listing Policy. GREEN VALLEY CREEK has four lines of evidence (LOEs 318114, 318144, 318451, 318851) and 1 of 8 samples exceed the guideline. JONIVE CREEK has three lines of evidence (LOEs 318164, 318168, 318172) and 0 of 7 samples exceed the guideline. LAKE GRATON has one line of evidence (LOE 318239) and 0 of 1 sample exceeds the guideline. REDWOOD CREEK has one line of evidence (LOE 318439) and 0 of 2 samples exceed the guideline. UNNAMED TRIBUTARY AT MONTGOMERY ROAD has one line of evidence (LOE 319022) and 0 of 1 sample exceeds the guideline. This listing applies to Atascadero Creek.

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:	***COLD FRESHWATER HABITAT BENEFICIAL USE: ATASCADERO CREEK has seven lines of evidence (LOEs 317799, 317804, 317808, 317812, 317816, 317820, 317824) and 11 of 23 samples exceed the guideline, which exceeds the allowable frequency in Table 3.2 of the Listing Policy. GREEN VALLEY CREEK has four lines of evidence (LOEs 318114, 318144, 318451, 318851) and 1 of 8 samples exceed the guideline. JONIVE CREEK has three lines of evidence (LOEs 318164, 318168, 318172) and 0 of 7 samples exceed the guideline. LAKE GRATON has one line of evidence (LOE 318239) and 0 of 1 sample exceeds the guideline. REDWOOD CREEK has one line of evidence (LOE 318439) and 0 of 2 samples exceed the guideline. UNNAMED TRIBUTARY AT MONTGOMERY ROAD has one line of evidence (LOE 319022) and 0 of 1 sample exceeds the guideline. This listing applies to Atascadero Creek.

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 163055, Specific Conductivity	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

26084

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:

Three of the 4 specific conductivity samples collected in the Green Valley Creek Watershed exceed the specific conductivity water quality objective. The sample concentrations range from 220 to 473 uS. The samples were collected as part of the Russian River First Flush sampling event. Data are summarized by Katznelson et al. (2003).

Data Reference:

2002 Russian River First Flush Summary Report. Clean Water Team, Citizen Monitoring Program of the State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Per the Basin Plan (NCRWQCB 2007): The 90% upper limit specific conductance objective at 77 F is 375 micromhos (or uS/cm2). The 50% upper limit specific conductance objective at 77 F is 285 micromhos (or uS/cm2). The 90% and 50% upper limits represent the 90/50 percentile values of the monthly means for a calendar year. 90% or 50% or more of the values must be less than or equal to the upper limit.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - North Coast Region (Region 1)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected from 4 sites in the Green Valley Creek Watershed as follows: (1) in Green Valley Creek at Martinelli Road; (2) in Atascadero Creek at the Green Valley Road bridge; (3) in Graton Gulch at Railroad Avenue; and (4) in Atascadero Creek at Mill Station Road.

Temporal Representation:

The samples were collected on November 7, 2002. At each site, 1 to 3 instantaneous grab samples were collected over half hour increments. The data are averaged for each site when multiple samples were collected..

Environmental Conditions:

Samples were collected during the first runoff event of the rainy season.

QAPP Information:

Samples were collected in accordance with the study plan and quality control procedures described by Katznelson et al. (2003).

QAPP Information Reference(s):

2002 Russian River First Flush Summary Report. Clean Water Team, Citizen Monitoring Program of the State Water Resources Control Board

Line of Evidence (LOE) for Decision ID 163055, Specific Conductivity	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

318239

Pollutant:

Specific Conductivity

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 specific conductivity data for Proposition 1 Grant for Gold Ridge RCD and determined that 0 of 1 samples exceed the water quality objective for calendar year 2019.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Per the Basin Plan (NCRWQCB 2007): The 90% upper limit specific conductance objective at 77 F is 375 micromhos (or mS/cm2). The 50% upper limit specific conductance objective at 77 F is 285 micromhos (or mS/cm2). The 90% and 50% upper limits represent the 90/50 percentile values for a calendar year. 90% or 50% or more of the values must be less than or equal to the upper limit.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at sampling station name: Lake Graton inside southeast berm; station code: LKG-10.

Temporal Representation:

These samples were collected from 1/10/2019-6/5/2019.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 163055, Specific Conductivity	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

318851

Pollutant:

Specific Conductivity

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 specific conductivity data for USGS California Water Science Center and determined that calendar year 2017 does not exceed the 90% or 50% upper limit, so that 0 of 1 sample exceeds the water quality objective.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at sampling station name: GREEN VALLEY C A GRATON CA; station code: USGS-382619122531401.

Temporal Representation:

These samples were collected from 4/5/2017-5/3/2017.

Environmental Conditions:

QAPP Information:

QAPP for USGS California Water Science Center

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 163055, Specific Conductivity	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

318144

Pollutant:

Specific Conductivity

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 specific conductivity data for parent project Proposition 1 Grant for Gold Ridge RCD and determined that calendar year 2020 does not exceed either the 90% or 50% upper limit, so that 0 of 1 sample exceeds the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Per the Basin Plan (NCRWQCB 2007): The 90% upper limit specific conductance objective at 77 F is 150 micromhos (or mS/cm2). The 50% upper limit specific conductance objective at 77 F is 125 micromhos (or mS/cm2). The 90% and 50% upper limits represent the 90/50 percentile values for a calendar year. 90% or 50% or more of the values must be less than or equal to the upper limit.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

This sample was collected at sampling station name: Hwy 116 crossing over Green Valley Creek; station code: GVC-45.

Temporal Representation:

This sample was collected on 1/16.2020.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 163055, Specific Conductivity	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

317804

Pollutant:

Specific Conductivity

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 data from parent project Proposition 1 Grant for Gold Ridge RCD and determined that calendar years 2018, 2019, 2020, and 2021 do not exceed either the 90% or 50% upper limit, so that 0 of 4 samples exceed the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at station name: Atascadero @ Mill Station Road xing; station code: ATC-40

Temporal Representation:

These samples were collected from 11/29/2018-3/18/2021

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 163055, Specific Conductivity	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

317820

Pollutant:

Specific Conductivity

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 data from parent project Proposition 1 Grant for Gold Ridge RCD and determined calendar years 2018, 2019, and 2021 do not exceed either the 90% or 50% upper limit and calendar year 2020 exceeds both the 90% and 50% upper limit, so that 1 of the 4 samples exceed the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at station name: Atascadero Creek @ Graton Road xing; station code: ATC-20.

Temporal Representation:

These samples were collected from 11/29/2018-3/18/2021.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 163055, Specific Conductivity	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

317824

Pollutant:

Specific Conductivity

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 data from parent project Proposition 1 Grant for Gold Ridge RCD and determined that calendar year 2018 exceeds the 50% upper limit, calendar year 2019 exceeds the 90% upper limit, calendar year 2020 exceeds both the 90% and 50% upper limits, and calendar year 2021 exceeds the 50% upper limit, so that 4 of the 4 samples exceed the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Per the Basin Plan (NCRWQCB 2007): The 90% upper limit specific conductance objective at 77 F is 285 micromhos (or mS/cm2). The 50% upper limit specific conductance objective at 77 F is 375 micromhos (or mS/cm2). The 90% and 50% upper limits represent the 90/50 percentile values for a calendar year. 90% or 50% or more of the values must be less than or equal to the upper limit.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at station name: Atascadero Creek @ Graton Road xing; station code: ATC-20.

Temporal Representation:

These samples were collected from 1/9/2019-3/19/2021.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 163055, Specific Conductivity	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

317799

Pollutant:

Specific Conductivity

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 data from parent project Proposition 1 Grant for Gold Ridge RCD and determined that 0 of 1 sample exceeds the 90% or 50% upper limit, so that 0 of 1 sample exceeds the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at station name: Atascadero @ Barnett Valley Road xing; station code: ATC-80

Temporal Representation:

This sample was collected on 2/26/2019.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 163055, Specific Conductivity	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

317808

Pollutant:

Specific Conductivity

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 data from parent project Proposition 1 Grant for Gold Ridge RCD and determined that calendar years 2018, 2019, and 2021 do not exceed either the 90% or 50% upper limit and that calendar year 2020 exceeds the 50% upper limit, so that 1 of 4 samples exceed the water quality objec

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at station name: Atascadero @ Occidental Road xing; station code: ATC-30.

Temporal Representation:

These samples were collected from 11/29/2018-3/18/2021.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 163055, Specific Conductivity	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

318114

Pollutant:

Specific Conductivity

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 specific conductivity data for parent project Proposition 1 Grant for Gold Ridge RCD and determined that calendar year 2020 exceeds the 50% upper limit and calendar years 2020 and 2022 do not exceed either the 90% or 50% upper limit, so that 1 of 3 samples exceed the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at sampling station name: Green Valley Creek at Green Valley Road crossing (lower); station code: GVC-60.

Temporal Representation:

These samples were collected from 5/14/2019-3/18/2021.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 163055, Specific Conductivity	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

319022

Pollutant:

Specific Conductivity

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 specific conductivity data for USGS California Water Science Center and determined that calendar year 2017 does not exceed either the 90% or 50% upper limit, so tha 0 of 1 sample exceeds the water quality objective.

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at sampling station name: UNNAMED TRIB A MONTGOMERY RD NR SEBASTOPOL CA; station code: USGS-382346122521201.

Temporal Representation:

These samples were collected from 4/5/2017-5/3/2017.

Environmental Conditions:

QAPP Information:

QAPP for USGS California Water Science Center

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 163055, Specific Conductivity	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

318451

Pollutant:

Specific Conductivity

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 specific conductivity data for QAPP for Proposition 1 Grant for Gold Ridge RCD and determined that calendar years 2019, 2020, and 2021 did not exceed either the 90% upper limit of 375 micromhos or the 50% upper limit of 285 micromhos, so that 0 of 3 samples exceed the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at sampling station name: Ross Station Road crossing over Green Valley Creek; station code: GVC-50.

Temporal Representation:

These samples were collected from 5/14/2019-3/18/2021.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 163055, Specific Conductivity	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

318172

Pollutant:

Specific Conductivity

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 specific conductivity data and determined that 0 of 1 sample for 2018, 0 of 1 sample for 2019, 0 of 1 sample for 2020, and 0 of 1 sample for 2021 exceed the 90% upper limit of 375 micromhos or the 50% upper limit of 285 micromhos, so that 0 of 4 samples exceed the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at sampling station name: Jonive Creek @ Sexton Road xing; station code: JOC-40.

Temporal Representation:

These samples were collected from 11/29/2018-3/28/2021.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 163055, Specific Conductivity	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

318168

Pollutant:

Specific Conductivity

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 specific conductivity data for parent project Proposition 1 Grant for Gold Ridge RCD and determined that calendar years 2018 and 2019 do not exceed either the 90% or 50% upper limit, so that 0 of 2 samples exceed the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at sampling station name: Jonive Creek @ Furlong Road xing; station code: JOC-50.

Temporal Representation:

These samples were collected from 11/29/2018-2/26/2019.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 163055, Specific Conductivity	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

318439

Pollutant:

Specific Conductivity

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 specific conductivity data for Proposition 1 Grant for Gold Ridge RCD and determined that calendar years 2019 and 2021 did not exceed either the 90% upper limit of 375 micromhos or the 50% upper limit of 285 micromhos, so that 0 of 2 samples exceed the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Per the Basin Plan (NCRWQCB 2007): The 90% upper limit specific conductance objective at 77 F is 285 micromhos (or mS/cm2). The 50% upper limit specific conductance objective at 77 F is 250 micromhos (or mS/cm2). The 90% and 50% upper limits represent the 90/50 percentile values for a calendar year. 90% or 50% or more of the values must be less than or equal to the upper limit.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected from sampling station name: Redwood Creek @ Furlong Road xing; station code: REC-20.

Temporal Representation:

These samples were collected from 1/9/2019-3/18/2021.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 163055, Specific Conductivity	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

317812

Pollutant:

Specific Conductivity

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 data from parent project Proposition 1 Grant for Gold Ridge RCD and determined that in calendar year 2018 exceeds the 50% upper limit, calendar year 2019 exceeds the 90% upper limit, calendar year 2020 exceeds both the 90% and 50% upper limits, and calendar year 2021 does not exceed either the 90% or 50% upper limit, so that 3 of 4 samples exceed the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at station name: Atascadero @ Watertrough Road xing; station code: ATC-60.

Temporal Representation:

These samples were collected from 11/29/2018-3/18/2021.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 163055, Specific Conductivity	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

317816

Pollutant:

Specific Conductivity

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 data from parent project Proposition 1 Grant for Gold Ridge RCD and determined that calendar years 2019 and 2020 exceed the 90% upper limit, so that 2 of 2 samples exceed the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at station name: Atascadero Creek @ Atascadero Creek Ecological Reserve southwest/Atascadero Creek frontage berm; station code: ATC-08.

Temporal Representation:

These samples were collected from 2/13/2019-6/4/2020.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 163055, Specific Conductivity	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

318164

Pollutant:

Specific Conductivity

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:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at sampling station name: Jonive Creek @ Ferguson Road xing; station code: JOC-20.

Temporal Representation:

These samples were collected on 5/18/2020-12/17/2020.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679


DECISION ID	156749	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

Pollutant:	pH
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. Sixteen lines of evidence are available in the administrative record to assess this pollutant. ATASCADERO CREEK (73 exceedances out of 286 samples) Atascadero Creek @ Atascadero Creek Ecological Reserve Southwest/Atascadero Creek frontage berm: LOE 317815 (72/239) Atascadero Creek @ Barnett Valley Road Crossing: LOE 317798 (0/1) Atascadero Creek @ Graton Road Xing: LOE 317819 (1/13); 317823 (1/14) Atascadero @ Mill Station Road Xing: LOE 317803 (0/10) Atascadero Creek @ Occidental Road Xing: LOE 317807 (0/10) Atascadero Creek @ Watertrough Road Xing: LOE 317811 (0/10) Atascadero Creek at the Green Valley Bridge: LOE 26085 (0/1) Atascadero Creek at Mill Station Road: LOE 26805 (0/1) GREEN VALLEY CREEK (0 exceedances out of 99 samples) Green Valley Creek: LOE 26093 (0/86) Green Valley Creek at Green Valley Road crossing (lower): LOE 318113 (0/6) Ross Station Road crossing over Green Valley Creek: LOE 318450 (0/7) JONIVE CREEK (0 exceedances out of 17 samples) Jonive Creek @ Ferguson Road Xing: LOE 318163 (0/3) Jonive Creek @ Furlong Road Xing: LOE 318167 (0/3) Jonive Creek @ Sexton Road Xing: LOE 318171 (0/11) LAKE GRATON (42 exceedances out of 133) samples) Lake Graton inside southeast berm: LOE 318238 (42/133) REDWOOD CREEK (0 exceedances out of 4 samples) *Redwood Creek @ Furlong Road Xing: LOE 318438 (0/4) 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. Seventy-two of 239 samples exceed the objective at Atascadero Creek Marsh Ecological Reserve and 42 of 133 samples exceed the objective at Lake Graton, 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. This listing only applies to Atascadero Creek Marsh Ecological Reserve and Lake Graton.

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 156749, pH	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

318167

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 the pH data and determined that 0 samples were less than pH 6.5 and 0 samples were greater than pH 8.5, so that 0 of 3 samples exceed the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Basin, Chapter III, General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: The pH shall conform to the values listed in Table 3-1 which states that the water quality objective for pH shall not be depressed below 6.5 or raised above 8.5.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at sampling station name: Jonive Creek @ Furlong Road xing; station code: JOC-50.

Temporal Representation:

These samples were collected from 11/29/2018-2/26/2019.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156749, pH	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

318171

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 the pH data and determined that 0 samples were less than pH 6.5 and 0 samples were greater than pH 8.5, so that 0 of 11 samples exceed the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at sampling station name: Jonive Creek @ Sexton Road xing; station code: JOC-40.

Temporal Representation:

These samples were collected from 11/29/2018-3/28/2021.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156749, pH	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

318238

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

133

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed pH data for Proposition 1 Grant for Gold Ridge RCD and determined that 1940 samples are less than pH 6.5 and 0 samples are greater than pH 8.5, so that 1940 of 8159 samples exceed the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at sampling station name: Lake Graton inside southeast berm; station code: LKG-10.

Temporal Representation:

These samples were collected from 1/10/2019-6/5/2019.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156749, pH	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

26085

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

None of the 2 pH samples collected in the Green Valley Creek Watershed exceed the pH water quality objective. The sample pH concentrations range from 6.5 to 7. The samples were collected as part of the Russian River First Flush sampling event. Data are summarized by Katznelson et al. (2003).

Data Reference:

2002 Russian River First Flush Summary Report. Clean Water Team, Citizen Monitoring Program of the State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Per the Basin Plan (NCRWQCB 2007): The maximum pH objective is 8.5. The minimum pH objective is 6.5.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - North Coast Region (Region 1)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected from 2 sites in the Green Valley Creek Watershed as follows: (1) in Atascadero Creek at the Green Valley Road bridge, and (2) in Atascadero Creek at Mill Station Road.

Temporal Representation:

Environmental Conditions:

Samples were collected during the first runoff event of the rainy season.

QAPP Information:

Samples were collected in accordance with the study plan and quality control procedures described by Katznelson et al. (2003).

QAPP Information Reference(s):

2002 Russian River First Flush Summary Report. Clean Water Team, Citizen Monitoring Program of the State Water Resources Control Board

Line of Evidence (LOE) for Decision ID 156749, pH	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

26093

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

None of the 86 samples for pH collected in Green Valley Creek exceeded the pH water quality objective. The pH values ranged from 6.6 to 8.1. These samples were collected by the Community Clean Water Institute¿s Volunteer Water Quality Monitoring Program (CCWI 2006, CCWI 2007).

Data Reference:

Community Clean Water Institute Master Data for 2005. Downloaded from http://ccwi.org/issues/data.htm on August 25, 2008

Community Clean Water Institute Master Data for 2006. Downloaded from http://ccwi.org/issues/data.htm on August 25, 2008

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Per the Basin Plan (NCRWQCB 2007): The maximum pH objective is 8.5. The minimum pH objective is 6.5.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - North Coast Region (Region 1)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 7 sites along the entire mainstem of Green Valley Creek: from Harrison Grade and Green Valley Road to the Russian River confluence.

Temporal Representation:

The pH samples were collected during 86 site visits from July 2005 to December 2006. The pH samples were collected as instantaneous measurements and do not represent diurnal conditions.

Environmental Conditions:

There are no known environmental conditions (e.g., seasonality, land use practices, fire events, storms, etc.) that are related to these data.

QAPP Information:

Samples were collected in accordance with the "Community Clean Water Institute Volunteer Water Quality Monitoring Program Sampling and Analysis Methods" (CCWI 2007).

QAPP Information Reference(s):

Community Clean Water Institute Volunteer Water Quality Monitoring Program Sampling and Analysis Methods. Updated April 12, 2007

Line of Evidence (LOE) for Decision ID 156749, pH	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

317807

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 data from parent project Proposition 1 Grant for Gold Ridge RCD and determined that 0 of 10 sample exceeds the Water Quality Objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at station name: Atascadero @ Occidental Road xing; station code: ATC-30.

Temporal Representation:

These samples were collected from 1/9/2019-3/18/2021.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156749, pH	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

317811

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 data from parent project Proposition 1 Grant for Gold Ridge RCD and determined that 0 of 10 sample exceeds the Water Quality Objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at station name: Atascadero @ Watertrough Road xing; station code: ATC-60.

Temporal Representation:

These samples were collected from 11/29/2018-3/18/2021.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156749, pH	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

317815

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

239

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed pH data from parent project Proposition 1 Grant for Gold Ridge RCD and determined that 72 samples are less than pH 6.5 and 0 samples are greater than pH 8.5, so that 72 of 239 samples exceed the Water Quality Objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at station name: Atascadero Creek @ Atascadero Creek Ecological Reserve southwest/Atascadero Creek frontage berm; station code: ATC-08.

Temporal Representation:

These samples were collected from 1/29/2019-6/4/2020.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156749, pH	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

317819

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 data from parent project Proposition 1 Grant for Gold Ridge RCD and determined that 1 of 13 samples was less than pH 6.5 and 0 of 13 samples were greater than 8.5, so that 1 of 13 samples exceeded the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at station name: Atascadero Creek @ Graton Road xing; station code: ATC-20.

Temporal Representation:

These samples were collected from 11/29/2018-3/18/2021.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156749, pH	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

317823

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 data from parent project Proposition 1 Grant for Gold Ridge RCD and determined that 1 of 14 samples was less than pH 6.5 and 0 of 14 samples were greater than 8.5, so that 1 of 14 samples exceeded the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at station name: Atascadero Creek @ Graton Road xing; station code: ATC-20.

Temporal Representation:

These samples were collected from 1/9/2019-3/19/2021.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156749, pH	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

317798

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 pH data from parent project Proposition 1 Grant for Gold Ridge RCD and determined that 0 of the 1 sample exceeds the Water Quality Objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at station name: Atascadero @ Barnett Valley Road xing; station code: ATC-80

Temporal Representation:

This sample was collected on 2/26/2019.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156749, pH	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

317803

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 data from parent project Proposition 1 Grant for Gold Ridge RCD and determined that 1 of the 6 samples exceed the Water Quality Objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at station name: Atascadero @ Mill Station Road xing; station code: ATC-40

Temporal Representation:

These samples were collected from 11/29/2018-3/18/2021

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156749, pH	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

318438

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 pH data for Proposition 1 Grant for Gold Ridge RCD and determined that 0 samples are less than pH 6.5 and 0 samples are greater than pH 8.5, so that 0 of 4 samples exceed the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected from sampling station name: Redwood Creek @ Furlong Road xing; station code: REC-20.

Temporal Representation:

These samples were collected from 1/9/2019-3/18/2021.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156749, pH	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

318450

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 pH data for QAPP for Proposition 1 Grant for Gold Ridge RCD and determined that 0 samples are less than pH 6.5 and 0 samples are greater than pH 8.5, so that 0 of 7 samples exceed the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at sampling station name: Ross Station Road crossing over Green Valley Creek; station code: GVC-50.

Temporal Representation:

These samples were collected from 5/14/2019-3/18/2021.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156749, pH	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

318113

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 the data and determined that 0 samples were less than pH 6.5 and 0 samples were greater than pH 8.5, so that 0 of 6 samples exceed the water quality objective for pH.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at sampling station name: Green Valley Creek at Green Valley Road crossing (lower); station code: GVC-60.

Temporal Representation:

These samples were collected from 5/14/2019-3/18/2021.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679

Line of Evidence (LOE) for Decision ID 156749, pH	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

318163

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 the pH data and determined that 0 samples were less than pH 6.5 and 0 samples were greater than pH 8.5, so that 0 of 3 samples exceed the water quality objective.

Data Reference:

Field, WQ from the Proposition 1 for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

These samples were collected at sampling station name: Jonive Creek @ Ferguson Road xing; station code: JOC-20.

Temporal Representation:

These samples were collected on 5/18/2020-12/17/2020.

Environmental Conditions:

QAPP Information:

QAPP for Proposition 1 Grant for Gold Ridge RCD

QAPP Information Reference(s):

Gold Ridge Resource Conservation District - QA doc (2010) - Proposition 1 Grant for Gold Ridge RCD - 402679


DECISION ID	168952	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

Pollutant:	Indicator Bacteria
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)(2018)
Revision Status	Original
Sources:	A Source Unknown
TMDL Priority:	High
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	The State Water Board’s Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California (the “ISWEBE Plan”) was adopted on August 7, 2018, and contains bacteria water quality objectives applicable to the REC-1 beneficial use. This has resulted in a change from assessing fecal coliform to assessing E. coli in fresh water and Enterococcus in saline water. Fecal coliform and freshwater enterococcus lines of evidence used in previous REC-1 beneficial use indicator bacteria decisions in the North Coast Region are not included in the 2026 Integrated Report assessment. The pollutant will again be considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. In accordance with section 6.1.5.3 of the Listing Policy, data should be representative of the critical timing that the pollutant is expected to impact the waterbody. Lacking constant inputs, indicator bacteria do not persist in the environment for a long period and effects are of relatively short duration. As a result, the historic levels of E. coli in the waterbody may be a poor indicator of current risks to human health, particularly when more recent data are available to sufficiently assess the water quality standard. Historic lines of evidence for data collected prior to October 21, 2012 (i.e., data collected more than 10 years from the 2026 data solicitation cutoff date) were evaluated pursuant to these considerations and, when more recent data were available, the pre-October 21, 2012, data were not used to assess water quality standards attainment because they do not meet the temporal representation requirements of section 6.1.5.3 of the Listing Policy. When no data after the October 21, 2012, timeframe were available, the historic data were evaluated to represent water quality conditions. Two lines of evidence are available in the administrative record to assess this pollutant. ATASCADERO CREEK AT GREEN VALLEY ROAD has one LOE (352452) and 2 of 2 geometric means exceed the E. coli objective. GREEN VALLEY CREEK AT MARTINELLI ROAD has one LOE (352453) and 6 of 17 geometric means exceed the E. coli objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from 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. Six of 17 geometric means exceed the E. coli objective at Green Valley Creek at Martinelli Road and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met. This listing applies to the mainstem of Green Valley Creek.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded. This listing applies to the mainstem of Green Valley Creek.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 168952, Indicator Bacteria	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

352453

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

GeoMean

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

6 of 17 geometric means exceed the E. coli objective.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation utilized in the RWQCB1 Russian River TMDL .

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California - Bacteria Provisions and a Water Quality Standards Variance Policy: The bacteria water quality objective for all waters where the salinity is equal to or less than 1 part per thousand (ppth) 95 percent or more of the time during the CALENDAR YEAR is: a STATISTICAL THRESHOLD VALUE (STV) of Escherichia coli of 320 cfu/100 mL not to be exceeded by more than 10 percent of the samples collected in a CALENDAR MONTH, calculated in a static manner.

Objective/Criterion Reference:

Amendment to the Water Quality Control Plan for Ocean Waters of California - Bacteria Provisions and a Water Quality Standards Variance Policy

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected at Green Valley Creek at Martinelli Road (114GV2455).

Temporal Representation:

Samples were collected from 12/19/2008 to 3/2/2012.

Environmental Conditions:

QAPP Information:

Data were collected in accordance with the Russian River Pathogen Indicator Bacteria TMDL QAPP (Version 1.0), Russian River Pathogen Indicator Bacteria TMDL - Supplemental Sampling Plan QAPP (Version 1.0), and/or the Russian River Pathogen Project QAPP.

QAPP Information Reference(s):

Russian River Pathogen Indicator Bacteria TMDL Quality Assurance Project Plan.

QAPP Information Reference(s):

Quality Assurance Project Plan - Russian River Pathogen Project.

QAPP Information Reference(s):

Russian River Pathogen Indicator Bacteria TMDL - Supplemental Sampling Plan Quality Assurance Project Plan.

Line of Evidence (LOE) for Decision ID 168952, Indicator Bacteria	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

352452

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

GeoMean

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

2 of 2 geometric means exceed the E. coli objective.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation utilized in the RWQCB1 Russian River TMDL .

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Amendment to the Water Quality Control Plan for Ocean Waters of California - Bacteria Provisions and a Water Quality Standards Variance Policy

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected at Atascadero Creek at Green Valley Road (114AT0714).

Temporal Representation:

Samples were collected from 11/7/2002 to 5/19/2009.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Russian River Pathogen Indicator Bacteria TMDL Quality Assurance Project Plan.

QAPP Information Reference(s):

Quality Assurance Project Plan - Russian River Pathogen Project.

QAPP Information Reference(s):

Russian River Pathogen Indicator Bacteria TMDL - Supplemental Sampling Plan Quality Assurance Project Plan.


DECISION ID	74844	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

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

Regional Board Conclusion:	Regional Water Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous Integrated Report cycle. No new information was reviewed for this current Integrated Report cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the Section 303(d) List under Section 3.2 of the Listing Policy. Under Section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. The weight of evidence indicates that there is insufficient information available to determine if it is appropriate to place this water segment-pollutant combination on the Section 303(d) List in the Water Quality Limited Segments category. One of the 3 diazinon samples exceed the evaluation guideline used to interpret the water quality objective, and this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of 5 samples are needed for application of Table 3.2, and only 3 samples are available. This conclusion is also based on the staff findings that: (1) The data used satisfies the data quality requirements of Section 6.1.4 of the Policy. (2) 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:	This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 74844, Diazinon	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

26091

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

One of the 3 diazinon samples collected from the Green Valley Creek Watershed exceeds the evaluation guideline. The sample concentrations range from non-detect to 23 ug/l. The samples were collected as part of the Russian River First Flush sampling event. Data are summarized by Katznelson et al. (2003).

Data Reference:

2002 Russian River First Flush Summary Report. Clean Water Team, Citizen Monitoring Program of the State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Per the Basin Plan (NCRWQCB 2007): 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.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - North Coast Region (Region 1)

Evaluation Guideline:

Per the National Recommended Water Quality Criteria (UEEPA 2006): The 1-hour average maximum concentration criterion for freshwater aquatic life protection if 0.08 ug/l.

Guideline Reference:

Spatial Representation:

The samples were collected from 3 sites in the Green Valley Creek Watershed as follows: (1) in Green Valley Creek at Martinelli Road; (2) in Atascadero Creek at the Green Valley Road bridge; and (3) in Graton Gulch at Railroad Avenue.

Temporal Representation:

The samples were collected on November 7, 2002. At each site, 3 instantaneous grab samples were collected over half hour increments. The data are averaged for each site.

Environmental Conditions:

Samples were collected during the first runoff event of the rainy season.

QAPP Information:

Samples were collected in accordance with the study plan and quality control procedures described by Katznelson et al. (2003).

QAPP Information Reference(s):

2002 Russian River First Flush Summary Report. Clean Water Team, Citizen Monitoring Program of the State Water Resources Control Board


DECISION ID	74883	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

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

Regional Board Conclusion:	Regional Water Board conclusion: This pollutant was considered for placement on the section 303(d) List in a previous Integrated Report cycle. No new information was reviewed for this current Integrated Report cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the Section 303(d) List under Section 3.1 of the Listing Policy. Under Section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. It is unknown if any of the phosphorus samples exceed the water quality objective as there is insufficient information available to determine exceedance. Specifically, the samples cannot be compared to the objective because diel samples for dissolved oxygen (DO), pH, and/or chlorophyll-a are not available. Nutrients such as phosphorus do not impair beneficial uses by themselves, or cause non-attainment of the objective. Rather, they cause indirect impacts through algal growth and extreme diel patterns for DO and pH, which then impair uses. Waterbody-specific factors such as riparian cover, flow conditions, and stream channel configuration also affect how nutrients are processed within the stream and play a large role in determining whether or not nuisance algal conditions will prevail. For these reasons, comparing a single nutrient value to the biostimulatory objective is not recommended. Instead, nutrient-related indicator parameters, such as diel measurements of DO, pH, and/or chlorophyll-a, should be evaluated to determine attainment of the objective and protection of beneficial uses. When nutrient-related indicator parameters exceed targets, nutrient concentrations will then be analyzed to determine whether phosphorus should be added to a possible listing under the 303(d) List. Therefore, the weight of evidence indicates that there is insufficient information available to determine if it is appropriate to place this water segment-pollutant combination on the Section 303(d) List in the Water Quality Limited Segments category. This conclusion is also 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) 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:	This region was not assessed this cycle. All decisions have been carried over from the previous cycle and remain the same.

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 74883, Phosphorus	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

26095

Pollutant:

Phosphorus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

It is unknown whether any of the 61 phosphorus samples collected in Green Valley Creek exceed the objective as there is insufficient information available to determine exceedance. Specifically, the samples cannot be compared to the objective because diel samples for dissolved oxygen (DO), pH, and/or chlorophyll-a are not available. Nutrients, such as phosphorus, alone do not impair beneficial uses or cause non-attainment of the objective. Rather, they cause indirect impacts through algal growth and extreme diel patterns for DO and pH, which then impair uses. Waterbody-specific factors such as riparian cover, flow conditions, and stream channel configuration also affect how nutrients are processed within the stream and play a large role in determining whether or not nuisance algal conditions will prevail. For these reasons, comparing a single nutrient value to the biostimulatory objective is not recommended. Instead, nutrient-related indicator parameters, such as diel measurements of DO, pH, and/or chlorophyll-a, should be evaluated to determine attainment of the objective and protection of beneficial uses. When nutrient-related indicator parameters exceed targets, nutrient concentrations will then be analyzed to determine whether phosphorus should be added to a possible listing under the 303(d) List. The sample concentrations range from non-detect (reporting limits of 0.03 mg/L and 0.1 mg/L) to 0.27 mg/L. These samples were collected by the Community Clean Water Institute¿s Volunteer Water Quality Monitoring Program (CCWI 2005, CCWI 2006, and CCWI 2007).

Data Reference:

Community Clean Water Institute Master Data for 2005. Downloaded from http://ccwi.org/issues/data.htm on August 25, 2008

Community Clean Water Institute Master Data for 2006. Downloaded from http://ccwi.org/issues/data.htm on August 25, 2008

Community Clean Water Institute Master Data for 2004. Downloaded from http://ccwi.org/issues/data.htm on October 1, 2008

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Per the Basin Plan (NCRWQCB 2007): Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - North Coast Region (Region 1)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 7 sites along the entire mainstem of Green Valley Creek: from Harrison Grade and Green Valley Road to the Russian River confluence.

Temporal Representation:

The samples were collected from July 2005 to December 2006.

Environmental Conditions:

There are no known environmental conditions (e.g., seasonality, land use practices, fire events, storms, etc.) that are related to these data.

QAPP Information:

Samples were collected in accordance with the "Community Clean Water Institute Volunteer Water Quality Monitoring Program Sampling and Analysis Methods" (CCWI 2007).

QAPP Information Reference(s):

Community Clean Water Institute Volunteer Water Quality Monitoring Program Sampling and Analysis Methods. Updated April 12, 2007

Line of Evidence (LOE) for Decision ID 74883, Phosphorus	Region 1
Russian River HU, Lower Russian River HA, Guerneville HSA, Green Valley Creek watershed

LOE ID:

26087

Pollutant:

Phosphorus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

It is unknown whether any of the 5 phosphorus samples collected in the Green Valley Creek Watershed exceed the objective as there is insufficient information available to determine exceedance. Specifically, the samples cannot be compared to the objective because diel samples for dissolved oxygen (DO), pH, and/or chlorophyll-a are not available. Nutrients, such as phosphorus, alone do not impair beneficial uses or cause non-attainment of the objective. Rather, they cause indirect impacts through algal growth and extreme diel patterns for DO and pH, which then impair uses. Waterbody-specific factors such as riparian cover, flow conditions, and stream channel configuration also affect how nutrients are processed within the stream and play a large role in determining whether or not nuisance algal conditions will prevail. For these reasons, comparing a single nutrient value to the biostimulatory objective is not recommended. Instead, nutrient-related indicator parameters, such as diel measurements of DO, pH, and/or chlorophyll-a, should be evaluated to determine attainment of the objective and protection of beneficial uses. When nutrient-related indicator parameters exceed targets, nutrient concentrations will then be analyzed to determine whether phosphorus should be added to a possible listing under the 303(d) List. Sample concentrations ranged from 0.21 to 0.86 mg/l. The samples were collected as part of the Russian River First Flush sampling event. Data are summarized by Katznelson et al. (2003).

Data Reference:

2002 Russian River First Flush Summary Report. Clean Water Team, Citizen Monitoring Program of the State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - North Coast Region (Region 1)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

Environmental Conditions:

Samples were collected during the first runoff event of the rainy season.

QAPP Information:

Samples were collected in accordance with the study plan and quality control procedures described by Katznelson et al. (2003).

QAPP Information Reference(s):

2002 Russian River First Flush Summary Report. Clean Water Team, Citizen Monitoring Program of the State Water Resources Control Board