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

Supporting Information

Regional Board 1 - North Coast Region

Water Body Name:	Klamath River HU, Butte Valley HA
Water Body ID:	CAR1058103319990610123037
Water Body Type:	River & Stream


DECISION ID	157131	Region 1
Klamath River HU, Butte Valley HA

Pollutant:	Temperature, water
Final Listing Decision:	Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Delist from 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Reason for Delisting:	Flaws in original listing
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. Five lines of evidence are available in the administrative record to assess this pollutant. For ANTELOPE CREEK (LOEs 43972, 329273), 0 of 2 samples exceed the cold freshwater habitat beneficial use objective. For BUTTE CREEK (LOEs 44095, 326924), 0 of 3 samples exceed the cold freshwater habitat beneficial use objective. For SPRING CREEK (LOE 326991), 0 of 8 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 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 ANTELOPE CREEK (LOEs 43972, 329273), 0 of 2 samples exceed the cold freshwater habitat beneficial use objective; for BUTTE CREEK (LOEs 44095, 326924), 0 of 3 samples exceed the cold freshwater habitat beneficial use objective; for SPRING CREEK (LOE 326991), 0 of 8 samples exceed the cold freshwater habitat beneficial use objective. This is insufficient data to apply Table 3.2 or 4.2 in 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.

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 157131, Temperature, water	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

3672

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Not Specified

Fraction:

None

Beneficial Use:

Wetland Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.

Data Reference:

Placeholder reference pre-2006 303(d)

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Unknown

Temporal Representation:

Unknown

Environmental Conditions:

Unknown

QAPP Information:

Unknown

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 157131, Temperature, water	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

43972

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:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Klamath River HU, Butte Valley HA to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Water Temperature.

Data Reference:

Statewide Perennial Streams Assessment 2008

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2011): 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:

Per "Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids" (Carter 2008): The lethal temperature evaluation guideline for adult migration & holding and juvenile growth & rearing of 24°C applies in this water body July - September 15th. The lethal temperature evaluation guideline for trout spawning, egg incubation & fry emergence is 20C and applies September 16th - June. See LOE ID 31536 for more information on natural temperature alterations and trout presence and periodicity in this water body.

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:

Data for this line of evidence for Klamath River HU, Butte Valley HA was collected at 1 monitoring site [ Antelope Creek 92 - 105PS0092 ]

Temporal Representation:

Data was collected on a single day 8/11/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 157131, Temperature, water	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

326991

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:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP Reference Condition Management Plan data for Klamath River HU, Butte Valley HA to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Temperature.

Data Reference:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

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 (Basin Plan, North Coast Region).

Objective/Criterion Reference:

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

Evaluation Guideline:

According to Carter (2008) the lethal temperature evaluation guideline for salmonid spawning, egg incubation & fry emergence is 20C.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 105PS0540 (Butte Creek ~1.5mi below Spring Creek).

Temporal Representation:

The samples were collected between the dates of 2015-08-03 and 2022-06-15

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 157131, Temperature, water	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

44095

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:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Klamath River HU, Butte Valley HA to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Water Temperature.

Data Reference:

Statewide Perennial Streams Assessment 2008

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:

Data for this line of evidence for Klamath River HU, Butte Valley HA was collected at 1 monitoring site [ Butte Creek 28 - 105PS0028 ]

Temporal Representation:

Data was collected over the time period 8/12/2008-8/26/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 157131, Temperature, water	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

326924

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:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP Perennial Stream Surveys data for Klamath River HU, Butte Valley HA to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature.

Data Reference:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program 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:

According to Carter (2008) the lethal temperature evaluation guideline for salmonid spawning, egg incubation & fry emergence is 20C.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 105PS1564 (Butte Creek ~10.3mi above E. Ball Mtn. Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-08-17 and 2015-08-17

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 157131, Temperature, water	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

329273

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:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed EPA National Aquatic Resources Survey (NARS) data for Klamath River HU, Butte Valley HA to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Temperature.

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:

According to Carter (2008) the lethal temperature evaluation guideline for salmonid spawning, egg incubation & fry emergence is 20C.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: NARS_WQX-CALS-1120 (Antelope Creek).

Temporal Representation:

The samples were collected between the dates of 2014-07-30 and 2014-07-30

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Generic SWAMP QAPrP


DECISION ID	157133	Region 1
Klamath River HU, Butte Valley HA

Pollutant:	Alkalinity as CaCO3
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 157133, Alkalinity as CaCO3	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

118153

Pollutant:

Alkalinity as CaCO3

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 Perennial Stream Surveys .

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) (105PS0540)

Temporal Representation:

The samples were collected between the dates of 2010-09-15 and 2010-09-15

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 157133, Alkalinity as CaCO3	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

322942

Pollutant:

Alkalinity as CaCO3

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

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:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

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:

The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 105PS1564 (Butte Creek ~10.3mi above E. Ball Mtn. Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-08-17 and 2015-08-17

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 157133, Alkalinity as CaCO3	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

322941

Pollutant:

Alkalinity as CaCO3

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program 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:

The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 105PS1564 (Butte Creek ~10.3mi above E. Ball Mtn. Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-08-17 and 2015-08-17

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 157133, Alkalinity as CaCO3	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

322924

Pollutant:

Alkalinity as CaCO3

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP Reference Condition Management Plan data for Klamath River HU, Butte Valley HA to determine beneficial use support and results are as follows: 0 of 7 samples exceeded the water quality threshold for Alkalinity as CaCO3.

Data Reference:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program 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:

The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 105PS0540 (Butte Creek ~1.5mi below Spring Creek).

Temporal Representation:

The samples were collected between the dates of 2015-08-03 and 2021-09-20

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 157133, Alkalinity as CaCO3	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

322885

Pollutant:

Alkalinity as CaCO3

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

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 SWAMP Reference Condition Management Plan data for Klamath River HU, Butte Valley HA to determine beneficial use support and results are as follows: 0 of 7 samples exceeded the water quality threshold for Alkalinity as CaCO3.

Data Reference:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

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:

The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 105PS0540 (Butte Creek ~1.5mi below Spring Creek).

Temporal Representation:

The samples were collected between the dates of 2015-08-03 and 2021-09-20

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Generic SWAMP QAPrP


DECISION ID	161409	Region 1
Klamath River HU, Butte Valley HA

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 161409, Ammonia	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

323428

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:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

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: 105PS1564 (Butte Creek ~10.3mi above E. Ball Mtn. Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-08-17 and 2015-08-17

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 161409, Ammonia	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

323427

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:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program 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:

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: 105PS1564 (Butte Creek ~10.3mi above E. Ball Mtn. Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-08-17 and 2015-08-17

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 161409, Ammonia	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

323300

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 SWAMP Reference Condition Management Plan data for Klamath River HU, Butte Valley HA to determine beneficial use support and results are as follows: 0 of 6 samples exceeded the water quality threshold for Ammonia as N.

Data Reference:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

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: 105PS0540 (Butte Creek ~1.5mi below Spring Creek).

Temporal Representation:

The samples were collected between the dates of 2015-08-03 and 2021-09-20

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 161409, Ammonia	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

323551

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 SWAMP Reference Condition Management Plan data for Klamath River HU, Butte Valley HA to determine beneficial use support and results are as follows: 0 of 6 samples exceeded the water quality threshold for Ammonia as N.

Data Reference:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

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: 105PS0540 (Butte Creek ~1.5mi below Spring Creek).

Temporal Representation:

The samples were collected between the dates of 2015-08-03 and 2021-09-20

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 161409, Ammonia	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

323566

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 SWAMP Reference Condition Management Plan data for Klamath River HU, Butte Valley HA to determine beneficial use support and results are as follows: 0 of 6 samples exceeded the water quality threshold for Ammonia as N.

Data Reference:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program 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:

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: 105PS0540 (Butte Creek ~1.5mi below Spring Creek).

Temporal Representation:

The samples were collected between the dates of 2015-08-03 and 2021-09-20

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 161409, Ammonia	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

323383

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

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: 105PS1564 (Butte Creek ~10.3mi above E. Ball Mtn. Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-08-17 and 2015-08-17

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Generic SWAMP QAPrP


DECISION ID	169283	Region 1
Klamath River HU, Butte Valley HA

Pollutant:	Benthic Community Effects
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:	Benthic Community Effects are being considered for placement on the CWA section 303(d) List under sections 3.9 of the Listing Policy. Under section 3.9, additional lines of evidence (LOEs) associating the Benthic Community Effects decision with a water or sediment concentration of pollutants other than benthic-macroinvertebrate bioassessment or habitat assessment LOEs are necessary to place a water body on the 303(d) List for Benthic Community Effects. Six lines of evidence evaluating benthic-macroinvertebrate bioassessment data are available in the administrative record to assess this indicator. Zero of fifteen benthic-macroinvertebrate samples exceed the California Stream Condition Index (CSCI) impairment threshold. These data indicate that the waterbody is likely unimpaired for Benthic Community Effects and therefore no other pollutant LOEs need be associated with this decision at this time. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing Benthic Community Effects in this waterbody segment on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of fifteen benthic-macroinvertebrate bioassessment samples had CSCI scores below 0.79. Therefore, this water body is not exceeding the water quality threshold for the protection of the COLD beneficial use. The available information indicates that the waterbody/pollutant combination should not be placed on the 303(d) List of impaired waters at this time. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 169283, Benthic Community Effects	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

352531

Pollutant:

Benthic-Macroinvertebrate Bioassessments

LOE Subgroup:

Population/Community Degradation

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Benthic macroinvertebrate surveys

Data Used to Assess Water Quality:

Water Board staff assessed data for 105PS0540 to determine beneficial use support and the results are as follows: 0 of 7 samples exceeded the water quality standard. CSCI scores were from 0.82175115096 to 1.179520963 .

Data Reference:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

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. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, bioassays of appropriate duration, or other appropriate methods as specified by the Regional Water Board (NCRWQCB 2018).

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:

The samples were collected at 1 monitoring site: 105PS0540 (Butte Creek ~1.5mi below Spring Creek).

Temporal Representation:

Samples were collected from 2015-08-03 to 2021-09-20.

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 169283, Benthic Community Effects	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

132736

Pollutant:

Habitat Assessment (Streams)

LOE Subgroup:

Ancillary Line of Evidence

Matrix:

-N/A

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

HABITAT ASSESSMENT

Data Used to Assess Water Quality:

The site had an IPI score of 1.12 which indicates the habitat is Likely Intact.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP Perennial Stream Surveys .

SWAMP Data:

SWAMP

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:

Physical characteristics of a site vary due to both natural factors and human disturbance. Statistical models based on a large statewide reference data set can help distinguish natural variability from anthropogenic stress. These models work across the diverse stream types found in California. The Index of Physical Habitat Integrity (IPI) is a multimetric Index developed based on these models to characterize physical habitat condition for streams in California. Index scores near 1 indicate physical habitat conditions similar to reference, whereas lower scores indicate degradation. For the purposes of making statewide assessments, three thresholds (analogous to those used for the CSCI) were established based on the 30th; 10th; and 1st percentiles of IPI scores at reference sites. These three thresholds divide the IPI scoring range into 4 categories of physical condition as follows: greater than or equal to 0.94 = likely intact condition; 0.93 to 0.84 = possibly altered condition; 0.83 to 0.71 = likely altered condition; less than or equal to 0.70 = very likely altered condition. Scores of 0.83 or lower indicate that the physical habitat has been altered and low CSCI scores from this site may be due to impacts to the physical habitat.

Guideline Reference:

An Index to Measure the Quality of Physical Habitat in California Wadeable Streams

Spatial Representation:

These samples were collected at the following station: 105PS0540

Temporal Representation:

These samples were collected on: 9/15/2010

Environmental Conditions:

QAPP Information:

Data collected following SWAMP QA protocols. QAPP for SWAMP Perennial Stream Surveys.

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 169283, Benthic Community Effects	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

96294

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 0.967881422. Therefore, this site is not exceeding the water quality objective for the aquatic life beneficial use.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for DFW_ABL_Monitoring.

SWAMP Data:

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

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: 105FC1120

Temporal Representation:

These samples were collected on: 7/30/2014

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

Line of Evidence (LOE) for Decision ID 169283, Benthic Community Effects	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

96330

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 1.012162038 & 0.812842491. Therefore, this site is not exceeding the water quality objective for the aquatic life beneficial use.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP Perennial Stream Surveys .

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:

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

Spatial Representation:

These samples were collected at the following station: 105PS1564 & 105PS0540

Temporal Representation:

These samples were collected on: 8/17/2015 & 9/15/2010

Environmental Conditions:

QAPP Information:

Data collected following SWAMP QA protocols. QAPP for SWAMP Perennial Stream Surveys.

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 169283, Benthic Community Effects	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

352532

Pollutant:

Benthic-Macroinvertebrate Bioassessments

LOE Subgroup:

Population/Community Degradation

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Benthic macroinvertebrate surveys

Data Used to Assess Water Quality:

Water Board staff assessed data for 105PS1564 to determine beneficial use support and the results are as follows: 0 of 1 samples exceeded the water quality standard. CSCI scores were from 0.809323309 to 0.809323309 .

Data Reference:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program 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:

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

Spatial Representation:

The samples were collected at 1 monitoring site: 105PS1564 (Butte Creek ~10.3mi above E. Ball Mtn. Rd.).

Temporal Representation:

Samples were collected from 2015-08-17 to 2015-08-17.

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 169283, Benthic Community Effects	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

96314

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 1.001300079, 0.967881, 1.009293

Therefore, this site is not exceeding the water quality objective for the aquatic life beneficial use. Additionally, this water body passed several screening criteria and was identified as a reference water body for the purposes of developing the CSCI. Reference sites where human disturbance is absent or minimal are used to set benchmark expectations for healthy streams. A large set of nearly 600 reference sites representing the broad diversity of natural stream types found across California was used to develop the CSCI.

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:

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

Spatial Representation:

These samples were collected at the following stations:
105FC1120
105SED077
105PS0540

Temporal Representation:

These samples were collected on: 8/3/2015, 7/30/2014, 9/16/2008

Environmental Conditions:

QAPP Information:

Data collected following SWAMP QA protocols. QAPP for SWAMP Reference Condition Management Plan.

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 169283, Benthic Community Effects	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

96324

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 1.001300079. Therefore, this site is not exceeding the water quality objective for the aquatic life beneficial use.

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:

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

Spatial Representation:

These samples were collected at the following station: 105PS0540

Temporal Representation:

These samples were collected on: 8/3/2015

Environmental Conditions:

QAPP Information:

Data collected following SWAMP QA protocols.. QAPP for SWAMP Reference Condition Management Plan.

QAPP Information Reference(s):

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


DECISION ID	157127	Region 1
Klamath River HU, Butte Valley HA

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 157127, Chloride	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

114854

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 DFW_ABL_Monitoring data for Klamath River HU, Butte Valley HA to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for Chloride.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for DFW_ABL_Monitoring.

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 secondary maximum contaminant level listed in Table 64449-B for chloride is 250 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) (105FC1120)

Temporal Representation:

The samples were collected between the dates of 2014-07-30 and 2014-07-30

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 157127, Chloride	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

44112

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Klamath River HU, Butte Valley HA to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Chloride.

Data Reference:

Statewide Perennial Streams Assessment 2008

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2011): 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 chloride is 250 mg/L.

Objective/Criterion Reference:

Secondary Maximum Contaminant Levels and Compliance. CCR Title 22 section 64449.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Klamath River HU, Butte Valley HA was collected at 1 monitoring sites [ Butte Creek 28 - 105PS0028 ]

Temporal Representation:

Data was collected over the time period 8/12/2008-8/26/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 157127, Chloride	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

104390

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 Perennial Stream Surveys .

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) (105PS0540)

Temporal Representation:

The samples were collected between the dates of 2010-09-15 and 2010-09-15

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 157127, Chloride	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

328161

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:

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: NARS_WQX-CALS-1120 (Antelope Creek).

Temporal Representation:

The samples were collected between the dates of 2014-07-30 and 2014-07-30

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 157127, Chloride	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

328129

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:

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: NARS_WQX-CALS-1120 (Antelope Creek).

Temporal Representation:

The samples were collected between the dates of 2014-07-30 and 2014-07-30

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 157127, Chloride	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

324013

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:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program 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:

The samples were collected at 1 monitoring site: 105PS1564 (Butte Creek ~10.3mi above E. Ball Mtn. Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-08-17 and 2015-08-17

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 157127, Chloride	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

324094

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 SWAMP Reference Condition Management Plan data for Klamath River HU, Butte Valley HA to determine beneficial use support and results are as follows: 0 of 7 samples exceeded the water quality threshold for Chloride.

Data Reference:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program 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:

The samples were collected at 1 monitoring site: 105PS0540 (Butte Creek ~1.5mi below Spring Creek).

Temporal Representation:

The samples were collected between the dates of 2015-08-03 and 2021-09-20

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 157127, Chloride	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

44113

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Klamath River HU, Butte Valley HA to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Chloride.

Data Reference:

Statewide Perennial Streams Assessment 2008

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Secondary Maximum Contaminant Levels and Compliance. CCR Title 22 section 64449.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Klamath River HU, Butte Valley HA was collected at 1 monitoring sites [ Antelope Creek 92 - 105PS0092 ]

Temporal Representation:

Data was collected on a single day 8/11/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 157127, Chloride	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

324083

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 SWAMP Reference Condition Management Plan data for Klamath River HU, Butte Valley HA to determine beneficial use support and results are as follows: 0 of 7 samples exceeded the water quality threshold for Chloride.

Data Reference:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program 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:

The samples were collected at 1 monitoring site: 105PS0540 (Butte Creek ~1.5mi below Spring Creek).

Temporal Representation:

The samples were collected between the dates of 2015-08-03 and 2021-09-20

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 157127, Chloride	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

324060

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:

Data Reference:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program 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:

The samples were collected at 1 monitoring site: 105PS1564 (Butte Creek ~10.3mi above E. Ball Mtn. Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-08-17 and 2015-08-17

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Generic SWAMP QAPrP


DECISION ID	155240	Region 1
Klamath River HU, Butte Valley HA

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

Regional Board Conclusion:	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 155240, Hardness as CaCO3	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

317940

Pollutant:

Hardness as CaCO3

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 the hardness data and determined that 0 of 1 sample for 2015, 0 of 1 sample for 2016, 1 of 1 sample for 2017, 0 of 0 samples for 2018, 0 of 0 samples for 2019, 0 of 1 sample for 2020, and 0 of 1 sample for 2021 exceed the 50% upper limit of 60 mg/L, so that 1 of 7 samples exceed the water quality objective.

Data Reference:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program 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 hardness shall conform to the values listed in Table 3-1 which states that the 50% upper limit hardness 30 mg/L. The 50% upper limit represents the 50 percentile values for a calendar year so that 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: Butte Creek ~1.5mi below Spring Creek; station code: 105PS0540.

Temporal Representation:

These samples were collected from 8/3/2015-9/20/2021.

Environmental Conditions:

QAPP Information:

QAPP for SWAMP Reference Condition Management Plan

QAPP Information Reference(s):

Generic SWAMP QAPrP


DECISION ID	157128	Region 1
Klamath River HU, Butte Valley HA

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:	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 157128, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

103816

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:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for DFW_ABL_Monitoring.

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(s) (105FC1120)

Temporal Representation:

The samples were collected between the dates of 2014-07-30 and 2014-07-30

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 157128, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

43968

Pollutant:

Nitrate/Nitrite (Nitrite + Nitrate as N)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Klamath River HU, Butte Valley HA to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Nitrate/Nitrite as N.

Data Reference:

Statewide Perennial Streams Assessment 2008

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2011): 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 nitrate+nitrite (sum as nitrogen) is 10.0 mg/L.

Objective/Criterion Reference:

Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Klamath River HU, Butte Valley HA was collected at 1 monitoring sites [ Butte Creek 28 - 105PS0028 ]

Temporal Representation:

Data was collected over the time period 8/12/2008-8/26/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 157128, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

43969

Pollutant:

Nitrate/Nitrite (Nitrite + Nitrate as N)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Statewide Perennial Streams Assessment 2008

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2011): 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 nitrate+nitrite (sum as nitrogen) is 10.0 mg/L.

Objective/Criterion Reference:

Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Klamath River HU, Butte Valley HA was collected at 1 monitoring sites [ Antelope Creek 92 - 105PS0092 ]

Temporal Representation:

Data was collected on a single day 8/11/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 157128, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

325810

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 SWAMP Reference Condition Management Plan data for Klamath River HU, Butte Valley HA to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Nitrate + Nitrite as N.

Data Reference:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program 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:

The samples were collected at 1 monitoring site: 105PS0540 (Butte Creek ~1.5mi below Spring Creek).

Temporal Representation:

The samples were collected between the dates of 2017-08-15 and 2018-09-18

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 157128, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

325827

Pollutant:

Nitrate/Nitrite (Nitrite + Nitrate as N)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program 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:

The samples were collected at 1 monitoring site: 105PS1564 (Butte Creek ~10.3mi above E. Ball Mtn. Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-08-17 and 2015-08-17

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 157128, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

107213

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:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP Perennial Stream Surveys .

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) (105PS0540)

Temporal Representation:

The samples were collected between the dates of 2010-09-15 and 2010-09-15

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 157128, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

325834

Pollutant:

Nitrate/Nitrite (Nitrite + Nitrate as N)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP Reference Condition Management Plan data for Klamath River HU, Butte Valley HA to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Nitrate + Nitrite as N.

Data Reference:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program 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:

The samples were collected at 1 monitoring site: 105PS0540 (Butte Creek ~1.5mi below Spring Creek).

Temporal Representation:

The samples were collected between the dates of 2015-08-03 and 2021-09-20

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Generic SWAMP QAPrP


DECISION ID	161367	Region 1
Klamath River HU, Butte Valley HA

Pollutant:	Nitrogen, 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)(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 161367, Nitrogen, Nitrate	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

325945

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 SWAMP Reference Condition Management Plan data for Klamath River HU, Butte Valley HA to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Nitrate as N.

Data Reference:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

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: 105PS0540 (Butte Creek ~1.5mi below Spring Creek).

Temporal Representation:

The samples were collected between the dates of 2018-09-18 and 2020-09-14

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 161367, Nitrogen, Nitrate	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

107694

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:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for DFW_ABL_Monitoring.

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(s) (105FC1120)

Temporal Representation:

The samples were collected between the dates of 2014-07-30 and 2014-07-30

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	161448	Region 1
Klamath River HU, Butte Valley HA

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 161448, Nitrogen, Nitrite	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

103527

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 DFW_ABL_Monitoring.

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(s) (105FC1120)

Temporal Representation:

The samples were collected between the dates of 2014-07-30 and 2014-07-30

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 161448, Nitrogen, Nitrite	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

326021

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 SWAMP Reference Condition Management Plan data for Klamath River HU, Butte Valley HA to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Nitrite as N.

Data Reference:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

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: 105PS0540 (Butte Creek ~1.5mi below Spring Creek).

Temporal Representation:

The samples were collected between the dates of 2018-09-18 and 2019-08-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 161448, Nitrogen, Nitrite	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

103130

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 Perennial Stream Surveys .

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) (105PS0540)

Temporal Representation:

The samples were collected between the dates of 2010-09-15 and 2010-09-15

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	105055	Region 1
Klamath River HU, Butte Valley HA

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

Regional Board Conclusion:	"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 three 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 105055, Nitrogen, ammonia (Total Ammonia)	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

34533

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

None of the samples exceed the water USEPA Temperature and pH-Dependent values of the CCC (Chronic Criterion) for Fish Early Life Stages Present for ammonia. Both data are reported as quantitation limits. These quantitation limits are less than or equal to the water quality standard, the value will be considered as meeting the water quality standard, objective, criterion, or evaluation guideline.

Data Reference:

Statewide Perennial Streams Assessment 2008

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2011): 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:

Update of Ambient Water Quality Criteria for Ammonia (USEPA 1999): Where salmonids and fish early life stages are present, the 30-day average concentration (criterion continuous concentration or CCC) of total ammonia (as mg N/L) in freshwater are not to be exceeded more than once every three years on average. The CCC values are based on pH, temperature, and the presence of early life stages of fish. The CCC formula is found on p.83 and the table of CCC values are found on p.87.

Guideline Reference:

1999 Update of Ambient Water Quality Criteria for Ammonia

Spatial Representation:

Samples were collected at 105PS0028 (Butte Creek 28).

Temporal Representation:

Samples were collected on 8/12/2008 and 8/26/2008.

Environmental Conditions:

QAPP Information:

SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 105055, Nitrogen, ammonia (Total Ammonia)	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

119348

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:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP Perennial Stream Surveys .

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) (105PS0540)

Temporal Representation:

The samples were collected between the dates of 2010-09-15 and 2010-09-15

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 105055, Nitrogen, ammonia (Total Ammonia)	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

117396

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:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for DFW_ABL_Monitoring.

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(s) (105FC1120)

Temporal Representation:

The samples were collected between the dates of 2014-07-30 and 2014-07-30

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 105055, Nitrogen, ammonia (Total Ammonia)	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

119650

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:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP Perennial Stream Surveys .

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) (105PS0540)

Temporal Representation:

The samples were collected between the dates of 2010-09-15 and 2010-09-15

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 105055, Nitrogen, ammonia (Total Ammonia)	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

103086

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:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP Perennial Stream Surveys .

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) (105PS0540)

Temporal Representation:

The samples were collected between the dates of 2010-09-15 and 2010-09-15

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 105055, Nitrogen, ammonia (Total Ammonia)	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

34534

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

The sample does not exceed the water USEPA Temperature and pH-Dependent values of the CCC (Chronic Criterion) for Fish Early Life Stages Present for ammonia. The datum was reported as a quantitation limit. This quantitation limit is less than or equal to the water quality standard, the value will be considered as meeting the water quality standard, objective, criterion, or evaluation guideline.

Data Reference:

Statewide Perennial Streams Assessment 2008

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:

1999 Update of Ambient Water Quality Criteria for Ammonia

Spatial Representation:

Samples were collected at 105PS0092 (Antelope Creek 92).

Temporal Representation:

The sample was collected on 8/11/2008.

Environmental Conditions:

QAPP Information:

SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	158411	Region 1
Klamath River HU, Butte Valley HA

Pollutant:	Sodium
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 158411, Sodium	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

329060

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:

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: NARS_WQX-CALS-1120 (Antelope Creek).

Temporal Representation:

The samples were collected between the dates of 2014-07-30 and 2014-07-30

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 158411, Sodium	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

118287

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:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for DFW_ABL_Monitoring.

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(s) (105FC1120)

Temporal Representation:

The samples were collected between the dates of 2014-07-30 and 2014-07-30

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 158411, Sodium	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

112292

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:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for DFW_ABL_Monitoring.

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(s) (105FC1120)

Temporal Representation:

The samples were collected between the dates of 2014-07-30 and 2014-07-30

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 158411, Sodium	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

329112

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:

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: NARS_WQX-CALS-1120 (Antelope Creek).

Temporal Representation:

The samples were collected between the dates of 2014-07-30 and 2014-07-30

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Generic SWAMP QAPrP


DECISION ID	163021	Region 1
Klamath River HU, Butte Valley HA

Pollutant:	Specific Conductivity
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 163021, Specific Conductivity	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

317942

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 for parent project SWAMP Reference Condition Management Plan and determined that calendar years 2015, 2016, 2017, 2018, 2019, 2020, 2021, and 2022 do not exceed either the 90% or 50% upper limit, so that 0 of 8 samples exceed the water quality objective.

Data Reference:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program 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 150 micromhos (or mS/cm2). The 50% upper limit specific conductance objective at 77 F is 100 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: Butte Creek ~1.5mi below Spring Creek; station code: 105PS0540.

Temporal Representation:

These samples were collected from 8/3/2015-9/20/2021.

Environmental Conditions:

QAPP Information:

QAPP for SWAMP Reference Condition Management Plan

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 163021, Specific Conductivity	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

317943

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 from parent project SWAMP Perennial Stream Surveys and determined that calendar year 2015 does not exceed the 90% or 50% upper limit, so that 0 of 1 sample exceeds the water quality objective.

Data Reference:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program 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:

This sample was collected at sampling station name: Butte Creek ~10.3mi above E. Ball Mtn. Rd.; station code: 105PS1564.

Temporal Representation:

This sample was collected on 8/17/2015.

Environmental Conditions:

QAPP Information:

QAPP for SWAMP Perennial Stream Surveys

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 163021, Specific Conductivity	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

318708

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 EPA National Aquatic Resources Survey (NARS) and determined that calendar year 2014 does not exceed either 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:

This sample was collected at sampling station name: Antelope Creek; station code: NARS_WQX-CALS-1120

Temporal Representation:

This sample was collected on 7/30/2014.

Environmental Conditions:

QAPP Information:

QAPP for EPA National Aquatic Resources Survey (NARS)

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 163021, Specific Conductivity	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

44473

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Klamath River HU, Butte Valley HA to determine beneficial use support and results are as follows: 0 of 1 samples exceed the objective for Specific Conductivity.

Data Reference:

Statewide Perennial Streams Assessment 2008

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2011): The site specific objective for Antelope Creek is a 90% upper limit of 150 uS. Therefore, 90% of the values in a calendar year must be lower than this limit. In addition the site specific objective of 50% upper limit of 100 uS which represents the 50 percentile values of the monthly means for a calendar year applies to this water body. Therefore, 50% or more of the monthly means in a calendar year must be less than or equal to an upper limit.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Klamath River HU, Butte Valley HA was collected at 1 monitoring site [Antelope Creek 92 - 105PS0092]

Temporal Representation:

Data was collected on a single day 8/11/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 163021, Specific Conductivity	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

100764

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed 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 specific conductivity. Data range from 224 uS/cm.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for DFW_ABL_Monitoring.

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 the following: Specific conductivity shall conform to Table 3-1 which states that water quality objective for specific conductivity has an 90% upper limit of 250 micromhos and a 50% upper limit of 150 micromhos.

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) Willow Creek, NF ~8.3mi above Boles Cr.
(105FC1116).

Temporal Representation:

The samples were collected between the dates 08/05/2014.

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 163021, Specific Conductivity	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

44462

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:

None of the values exceeded the objective,

Data Reference:

Statewide Perennial Streams Assessment 2008

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2011): The site specific objective for Butte Creek is a 90% upper limit of 150 uS. Therefore, 90% of the values in a calendar year must be lower than this limit. In addition the site specific objective of 50% upper limit of 100 uS which represents the 50 percentile values of the monthly means for a calendar year applies to this water body. Therefore, 50% or more of the monthly means in a calendar year must be less than or equal to an upper limit.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Klamath River HU, Butte Valley HA was collected at 1 monitoring site [Butte Creek 28 - 105PS0028]

Temporal Representation:

Data was collected over the time period 8/12/2008-8/26/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 163021, Specific Conductivity	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

100749

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed 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 specific conductance. Data range from 75.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP Perennial Stream Surveys .

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: Specific conductivity shall conform to Table 3-1 which states that water quality objective for specific conductivity has an 90% upper limit of 150 micromhos and a 50% upper limit of 100 micromhos.

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) Butte Creek ~1.5mi below Spring Creek
(105PS0540)

Temporal Representation:

The samples were collected between the dates 09/15/2010.

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


DECISION ID	157130	Region 1
Klamath River HU, Butte Valley HA

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 157130, Sulfates	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

44073

Pollutant:

Sulfates

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Klamath River HU, Butte Valley HA to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Sulfate.

Data Reference:

Statewide Perennial Streams Assessment 2008

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Secondary Maximum Contaminant Levels and Compliance. CCR Title 22 section 64449.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Klamath River HU, Butte Valley HA was collected at 1 monitoring sites [ Antelope Creek 92 - 105PS0092 ]

Temporal Representation:

Data was collected on a single day 8/11/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 157130, Sulfates	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

329229

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:

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: NARS_WQX-CALS-1120 (Antelope Creek).

Temporal Representation:

The samples were collected between the dates of 2014-07-30 and 2014-07-30

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 157130, Sulfates	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

326885

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 SWAMP Reference Condition Management Plan data for Klamath River HU, Butte Valley HA to determine beneficial use support and results are as follows: 0 of 7 samples exceeded the water quality threshold for Sulfate.

Data Reference:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program 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:

The samples were collected at 1 monitoring site: 105PS0540 (Butte Creek ~1.5mi below Spring Creek).

Temporal Representation:

The samples were collected between the dates of 2015-08-03 and 2021-09-20

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 157130, Sulfates	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

112108

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 DFW_ABL_Monitoring.

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(s) (105FC1120)

Temporal Representation:

The samples were collected between the dates of 2014-07-30 and 2014-07-30

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 157130, Sulfates	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

44056

Pollutant:

Sulfates

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Klamath River HU, Butte Valley HA to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Sulfate.

Data Reference:

Statewide Perennial Streams Assessment 2008

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Secondary Maximum Contaminant Levels and Compliance. CCR Title 22 section 64449.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Klamath River HU, Butte Valley HA was collected at 1 monitoring sites [ Butte Creek 28 - 105PS0028 ]

Temporal Representation:

Data was collected over the time period 8/12/2008-8/26/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 157130, Sulfates	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

102869

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 Perennial Stream Surveys .

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) (105PS0540)

Temporal Representation:

The samples were collected between the dates of 2010-09-15 and 2010-09-15

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 157130, Sulfates	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

326821

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:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program 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:

The samples were collected at 1 monitoring site: 105PS1564 (Butte Creek ~10.3mi above E. Ball Mtn. Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-08-17 and 2015-08-17

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Generic SWAMP QAPrP


DECISION ID	157132	Region 1
Klamath River HU, Butte Valley HA

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 157132, Turbidity	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

327308

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:

Data Reference:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

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: 105PS0540 (Butte Creek ~1.5mi below Spring Creek).

Temporal Representation:

The samples were collected between the dates of 2015-08-03 and 2022-06-15

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 157132, Turbidity	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

329367

Pollutant:

Turbidity

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:

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:

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: NARS_WQX-CALS-1120 (Antelope Creek).

Temporal Representation:

The samples were collected between the dates of 2014-07-30 and 2014-07-30

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 157132, Turbidity	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

327263

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:

Data Reference:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program 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:

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: 105PS1564 (Butte Creek ~10.3mi above E. Ball Mtn. Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-08-17 and 2015-08-17

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Generic SWAMP QAPrP


DECISION ID	157129	Region 1
Klamath River HU, Butte Valley HA

Pollutant:	Oxygen, Dissolved
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. Fourteen lines of evidence are available in the administrative record to assess this pollutant. For the COLD beneficial use, there are seven LOEs and 2 of 14 samples exceed the guideline. For the SPWN beneficial use, there are three LOEs and 8 of 10 samples exceed the guideline. For the WARM beneficial use, there are four LOEs and 1 of 11 samples exceed the 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. For the COLD beneficial use, 2 of 14 samples, and for the WARM beneficial use, 1 of 11 samples exceed the guideline. For both, there is insufficient data to determine beneficial use support. For the SPWN beneficial use, 8 of 10 samples exceed the 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 only applies to Butte Creek. **FOR THE FISH SPAWNING BENEFICIAL USE: ANTELOPE CREEK has one LOE (328801) and 0 of 1 sample exceeds the guideline. *BUTTE CREEK has two LOEs (326294, 326295) and 8 of 9 samples exceed the guideline.

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:	**FOR THE FISH SPAWNING BENEFICIAL USE: ANTELOPE CREEK has one LOE (328801) and 0 of 1 sample exceeds the guideline. *BUTTE CREEK has two LOEs (326294, 326295) and 8 of 9 samples exceed the guideline.

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 157129, Oxygen, Dissolved	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

101345

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

If DO concentrations fall below the numeric objectives set forth by the Basin Plan (2018). If NO, then the waterbody is supporting that beneficial use, if YES, then that waterbody is considered impaired.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Dissolved oxygen (DO) concentrations shall conform to the numeric objectives expressed in section 3.3.5.

Objective/Criterion Reference:

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

Evaluation Guideline:

EVIDENCE OF SALMONID PRESENCE & LIFE CYCLE USE: Rainbow Trout, Brown Trout, and Brook Trout are all present in the Butte Valley HU (UC Davis 1993). Spawning, incubation and emergence for these trout species occurrs mid- September through June (Moyle 2002). Rearing occurrs year round.

Guideline Reference:

Inland Fishes of California

Spatial Representation:

Klamath River HU, Lower HA, Butte Valley HA

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 157129, Oxygen, Dissolved	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

328801

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial 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:

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: NARS_WQX-CALS-1120 (Antelope Creek).

Temporal Representation:

The samples were collected between the dates of 2014-07-30 and 2014-07-30

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 157129, Oxygen, Dissolved	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

328822

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

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:

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 WARM beneficial use waters to be a daily minimum of 5.0 mg/L and a 7-day moving average of 6.0 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: NARS_WQX-CALS-1120 (Antelope Creek).

Temporal Representation:

The samples were collected between the dates of 2014-07-30 and 2014-07-30

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 157129, Oxygen, Dissolved	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

328892

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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 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 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 1 monitoring site: NARS_WQX-CALS-1120 (Antelope Creek).

Temporal Representation:

The samples were collected between the dates of 2014-07-30 and 2014-07-30

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 157129, Oxygen, Dissolved	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

326258

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP Reference Condition Management Plan data for Klamath River HU, Butte Valley HA to determine beneficial use support and results are as follows: 1 of 8 samples exceeded the water quality threshold for Oxygen, Dissolved.

Data Reference:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program 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 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 1 monitoring site: 105PS0540 (Butte Creek ~1.5mi below Spring Creek).

Temporal Representation:

The samples were collected between the dates of 2015-08-03 and 2022-06-15

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 157129, Oxygen, Dissolved	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

326294

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial 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 SWAMP Perennial Stream Surveys data for Klamath River HU, Butte Valley HA to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Oxygen, Dissolved.

Data Reference:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program 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:

The samples were collected at 1 monitoring site: 105PS1564 (Butte Creek ~10.3mi above E. Ball Mtn. Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-08-17 and 2015-08-17

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 157129, Oxygen, Dissolved	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

107885

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP Perennial Stream Surveys .

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 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 1 monitoring site(s) (105PS0540)

Temporal Representation:

The samples were collected between the dates of 2010-09-15 and 2010-09-15

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 157129, Oxygen, Dissolved	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

112120

Pollutant:

Oxygen, Dissolved

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 Perennial Stream Surveys .

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 WARM beneficial use waters to be a daily minimum of 5.0 mg/L and a 7-day moving average of 6.0 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) (105PS0540)

Temporal Representation:

The samples were collected between the dates of 2010-09-15 and 2010-09-15

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 157129, Oxygen, Dissolved	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

33869

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:

The sample collected did not exceed the objective.

Data Reference:

Statewide Perennial Streams Assessment 2008

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2011): The site specific objective for streams in the Butte Valley HA is a minimum value of 7.0 mg/L. In addition, the 50% lower limit of 9.0 mg/L which represents the 50 percentile values of the monthly means for a calendar year applies to this water body. Therefore, 50% or more of the monthly means in a calendar year must be less than or equal to an upper limit.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One sample was collected from the Antelope Creek 92 station (105PS0092).

Temporal Representation:

One sample was collected in August 2008.

Environmental Conditions:

QAPP Information:

SWAMP QAPP

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 157129, Oxygen, Dissolved	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

33867

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:

One of the 2 samples exceeded the objective.

Data Reference:

Statewide Perennial Streams Assessment 2008

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:

Samples were collected from the Butte Creek 28 station (105PS0028).

Temporal Representation:

Two Samples were collected in August 2008.

Environmental Conditions:

QAPP Information:

SWAMP QAPP

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 157129, Oxygen, Dissolved	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

326260

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

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:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program 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 WARM beneficial use waters to be a daily minimum of 5.0 mg/L and a 7-day moving average of 6.0 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: 105PS1564 (Butte Creek ~10.3mi above E. Ball Mtn. Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-08-17 and 2015-08-17

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 157129, Oxygen, Dissolved	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

326262

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

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:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program 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 WARM beneficial use waters to be a daily minimum of 5.0 mg/L and a 7-day moving average of 6.0 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: 105PS0540 (Butte Creek ~1.5mi below Spring Creek).

Temporal Representation:

The samples were collected between the dates of 2015-08-03 and 2022-06-15

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 157129, Oxygen, Dissolved	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

326236

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program 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 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 1 monitoring site: 105PS1564 (Butte Creek ~10.3mi above E. Ball Mtn. Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-08-17 and 2015-08-17

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 157129, Oxygen, Dissolved	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

326295

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial 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 SWAMP Reference Condition Management Plan data for Klamath River HU, Butte Valley HA to determine beneficial use support and results are as follows: 7 of 8 samples exceeded the water quality threshold for Oxygen, Dissolved.

Data Reference:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program 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:

The samples were collected at 1 monitoring site: 105PS0540 (Butte Creek ~1.5mi below Spring Creek).

Temporal Representation:

The samples were collected between the dates of 2015-08-03 and 2022-06-15

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Generic SWAMP QAPrP


DECISION ID	155239	Region 1
Klamath River HU, Butte Valley HA

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. Six lines of evidence are available in the administrative record to assess this pollutant. Seven of the 14 samples exceed the Objective. For Antelope Creek, there are three lines of evidence with 1 of 3 samples exceeding the Objective, which is insufficient data quantity to apply the binomial distribution. For Butte Creek, there are three lines of evidence with 6 of 11 samples exceeding the Objective, which exceeds the allowable frequency in the binomial distribution. 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. Seven of the 14 samples for Butte Creek exceed the Objective and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. This listing only applies to Butte Creek. ANTELOPE CREEK has three LOEs (33909, 100724, 318707) and 1 of 3 samples exceed the objective. BUTTE CREEK has three LOEs (33907, 100709, 317941) and 6 of 11 samples exceed the objective.

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:	ANTELOPE CREEK has three LOEs (33909, 100724, 318707) and 1 of 3 samples exceed the objective. BUTTE CREEK has three LOEs (33907, 100709, 317941) and 6 of 11 samples exceed the objective.

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 155239, pH	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

100709

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 SWAMP Perennial Stream Surveys data for Klamath River HU, Middle HA, Iron Gate Dam to Scott River to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for pH.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP Perennial Stream Surveys .

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 for water bodies in Butte Valley shall not be depressed below 7.0 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:

The samples were collected at 1 monitoring site(s) Butte Creek ~1.5mi below Spring Creek
(105PS0540)

Temporal Representation:

The samples were collected between the date 09/15/2010.

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 155239, pH	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

33907

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:

One of the 2 samples exceeded the objective.

Data Reference:

Statewide Perennial Streams Assessment 2008

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2011): Table 3-1 states that the lower limit pH for surface water bodies for this water body is 7.0, and the upper limit pH is 8.5.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from the Butte Creek 28 station (105PS0028).

Temporal Representation:

Samples were collected twice in August 2008.

Environmental Conditions:

QAPP Information:

SWAMP QAPP

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 155239, pH	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

33909

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:

The sample collected did not exceed the objective.

Data Reference:

Statewide Perennial Streams Assessment 2008

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2011): Table 3-1 states that the lower limit pH for surface water bodies for this water body is 7.0, and the upper limit pH is 8.5.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One sample was collected from the Antelope Creek 92 station (105PS0092).

Temporal Representation:

One sample was collected in August 2008.

Environmental Conditions:

QAPP Information:

SWAMP QAPP

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 155239, pH	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

100724

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 for this water body to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for pH. Data range from 6.7.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for DFW_ABL_Monitoring.

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 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 7.0 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:

The samples were collected at 1 monitoring site(s) Antelope Creek ~1.8mi above Tennant Rd.
(105FC1120)

Temporal Representation:

The samples were collected between the date 07/30/2014.

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 155239, pH	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

317941

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 for parent project SWAMP Reference Condition Management Plan and determined that 0 of 8 samples have less than pH 7.0 and 5 of the 8 samples have greater than pH 8.5, so that 5 of 8 samples exceed the water quality objective for pH.

Data Reference:

Benthic, Field, Habitat, WQ from the Surface Water Ambient Monitoring Program 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: Butte Creek ~1.5mi below Spring Creek; station code: 105PS0540.

Temporal Representation:

These samples were collected from 8/3/2015-9/20/2021.

Environmental Conditions:

QAPP Information:

QAPP for SWAMP Reference Condition Management Plan

QAPP Information Reference(s):

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 155239, pH	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

318707

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 EPA National Aquatic Resources Survey (NARS) and determined that 0 samples are less than pH 7.0 and 0 samples are greater than pH 8.5, 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:

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 7.0 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:

This sample was collected at sampling station name: Antelope Creek; station code: NARS_WQX-CALS-1120

Temporal Representation:

This sample was collected on 7/30/2014.

Environmental Conditions:

QAPP Information:

QAPP for EPA National Aquatic Resources Survey (NARS)

QAPP Information Reference(s):

Generic SWAMP QAPrP


DECISION ID	79716	Region 1
Klamath River HU, Butte Valley HA

Pollutant:	Nutrients
Final Listing Decision:	Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Delist from 303(d) list (TMDL required list)(2016)
Revision Status	Original
Reason for Delisting:	Flaws in original listing
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the section 303(d) list under section 4.11 of the Listing Policy. The "Klamath River" was first placed on the 303(d) List for temperature in 1992 by the USEPA, and for nutrients in 1996. The Butte Valley HA is not part of the Klamath River watershed, as its streams are not tributaries to the Klamath River. The 1998 303(d) List clarified the Klamath listings as follows: "...TMDLs will be developed for the area tributary to and including: 1) Clear Lake Reservoir Area, 2) Lost River/Tule Lake to Oregon border, 3) Oregon border to Iron Gate dam, 4) Iron Gate Dam to Scott River, 5) Scott River to Trinity River, and 6) Trinity River to the Ocean". The Butte Valley HA is not tributary to any of the Klamath HU water body areas specified above. The Butte Valley HA first appears (is first specifically named) on the 2002 303(d) List, however there was no temperature or nutrient data evaluated for the Butte Valley HA in the staff report for the 2002 303(d) List. It appears that the Butte Valley HA was incorrectly included on the 2002 (and subsequent) 303(d) Lists for nutrient and temperature impairment because it was part of the Klamath River HU and not because there were data or information available for the water body that reflected impairment. A limited amount of nutrient data for the Butte Valley HA were available for assessment in the 2012 Integrated Report, however there were an insufficient number of samples to determine with the power and confidence of the Listing Policy if beneficial uses are not being supported, as a minimum of either (1) 16 samples, or (2) greater than or equal 2 exceedances of the evaluation guideline with less than 16 samples is needed for application of Table 3.1. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of removing this water segment-pollutant combination from the section 303(d) List. This conclusion is based on the staff findings that the original listing of the Butte Valley HA was in error, and that the intent of the temperature and nutrient listings was to list water bodies tributary to the Klamath River including: 1) Clear Lake Reservoir Area, 2) Lost River/Tule Lake to Oregon border, 3) Oregon border to Iron Gate dam, 4) Iron Gate Dam to Scott River, 5) Scott River to Trinity River, and 6) Trinity River to the Ocean, which does not include the streams in the Butte Valley HA. Additionally, there are not enough nutrient samples for streams within the Butte Valley HA water body to make a listing determination at the present time.

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 79716, Nutrients	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

43968

Pollutant:

Nitrate/Nitrite (Nitrite + Nitrate as N)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Statewide Perennial Streams Assessment 2008

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2011): 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 nitrate+nitrite (sum as nitrogen) is 10.0 mg/L.

Objective/Criterion Reference:

Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Klamath River HU, Butte Valley HA was collected at 1 monitoring sites [ Butte Creek 28 - 105PS0028 ]

Temporal Representation:

Data was collected over the time period 8/12/2008-8/26/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 79716, Nutrients	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

44010

Pollutant:

Nitrite as Nitrite NO2

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Klamath River HU, Butte Valley HA to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Nitrite as N.

Data Reference:

Statewide Perennial Streams Assessment 2008

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2011): 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:

Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Klamath River HU, Butte Valley HA was collected at 1 monitoring sites [ Butte Creek 28 - 105PS0028 ]

Temporal Representation:

Data was collected over the time period 8/12/2008-8/26/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 79716, Nutrients	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

44028

Pollutant:

Nitrite as Nitrite NO2

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Klamath River HU, Butte Valley HA to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Nitrite as N.

Data Reference:

Statewide Perennial Streams Assessment 2008

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2011): 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:

Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Klamath River HU, Butte Valley HA was collected at 1 monitoring sites [ Antelope Creek 92 - 105PS0092 ]

Temporal Representation:

Data was collected on a single day 8/11/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 79716, Nutrients	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

34533

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Statewide Perennial Streams Assessment 2008

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:

1999 Update of Ambient Water Quality Criteria for Ammonia

Spatial Representation:

Samples were collected at 105PS0028 (Butte Creek 28).

Temporal Representation:

Samples were collected on 8/12/2008 and 8/26/2008.

Environmental Conditions:

QAPP Information:

SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 79716, Nutrients	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

43969

Pollutant:

Nitrate/Nitrite (Nitrite + Nitrate as N)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Statewide Perennial Streams Assessment 2008

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2011): 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 nitrate+nitrite (sum as nitrogen) is 10.0 mg/L.

Objective/Criterion Reference:

Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Klamath River HU, Butte Valley HA was collected at 1 monitoring sites [ Antelope Creek 92 - 105PS0092 ]

Temporal Representation:

Data was collected on a single day 8/11/2008.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 79716, Nutrients	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

3671

Pollutant:

Nutrients

LOE Subgroup:

Pollutant-Water

Matrix:

Not Specified

Fraction:

None

Beneficial Use:

Wetland Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.

Data Reference:

Placeholder reference pre-2006 303(d)

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Unknown

Temporal Representation:

Unknown

Environmental Conditions:

Unknown

QAPP Information:

Unknown

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 79716, Nutrients	Region 1
Klamath River HU, Butte Valley HA

LOE ID:

34534

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Statewide Perennial Streams Assessment 2008

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:

1999 Update of Ambient Water Quality Criteria for Ammonia

Spatial Representation:

Samples were collected at 105PS0092 (Antelope Creek 92).

Temporal Representation:

The sample was collected on 8/11/2008.

Environmental Conditions:

QAPP Information:

SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan