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, Lost River HA, Tule Lake and Mt Dome HSAs
Water Body ID:	CAR1059101019990217163525
Water Body Type:	River & Stream


DECISION ID	168712	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

Pollutant:	Arsenic
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	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 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. Ten of 16 samples from the Klamath Straits Drain and 10 of 16 samples from pumping plant D (which drains Tule Lake) exceed the objective for the protection of the MUN beneficial use. 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. Ten of 16 samples from the Klamath Straits Drain and 10 of 16 samples from pumping plant D (which drains Tule Lake) exceed the objective for the protection of the MUN beneficial use. This exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. This listing applies to the entire waterbody. This listing applies to the entire waterbody.

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:	This listing applies to the entire waterbody.

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 168712, Arsenic	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

122917

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Ten of 16 samples exceeded the objective of 10 ug/L. Samples ranged from 7.3 ug/L to 16.8 ug/L.

Data Reference:

Data for pesticides collected by the Tule Lake Pesticide program, Apr. 2007-Oct. 2007 and data for metals and nutrients by the Klamath Water Quality program, Mar. 2006-Dec. 2009

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Basin (NCRWQCB 2011): Waters designated as domestic or municipal (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15 for Inorganic Chemicals and Organic Chemicals and listed in Table 3-2 of the Basin Plan. Footnote 2 from Table 3-2 states "Other water quality objectives (e.g. taste and odor threshold or other secondary MCLs)?that are more stringent may apply." The following provisions of Title 22, Chapter 15 of the California Code of Regulations contain the most updated information on MCLs and Secondary MCLs: Table 64431-A of Section 64431 (Inorganic Chemicals), Table 64444-A of Section 64444 (Organic Chemicals), Table 64449-A of Section 64449 (Secondary Maximum Contaminant Levels-Ranges). The maximum contaminant level listed in Table 64431-A for arsenic is 0.01 mg/L (10 ug/L).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from K-3 (Pumping Plant D).

Temporal Representation:

Samples were collected quarterly during the months of March, June, October, and December between the years 2006-2009.

Environmental Conditions:

QAPP Information:

Samples were collected and analyzed in accordance with the Klamath Water Quality Quarterly Sampling Quality Assurance Project Plan, prepared by the U.S. Bureau of Reclamation, Mid-Pacific Region Environmental Monitoring Branch, MP-157 on April 22, 2008 (Review Number 1).

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 168712, Arsenic	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

122916

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Ten of the 16 samples exceeded the objective of 10 ug/L. Sample values ranged from 5.3 ug/L to 56.6 ug/L.

Data Reference:

Data for pesticides collected by the Tule Lake Pesticide program, Apr. 2007-Oct. 2007 and data for metals and nutrients by the Klamath Water Quality program, Mar. 2006-Dec. 2009

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

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

Guideline Reference:

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

Spatial Representation:

Samples were collected from K-2 (Klamath Straits Drain @ Stateline).

Temporal Representation:

Samples were collected quarterly during the months of March, June, October, and December between the years 2006-2009.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):


DECISION ID	168714	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

Pollutant:	Mercury
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Sources:	A Source Unknown
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the CWA section 303(d) List under section 4.1 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. Four lines of evidence (LOE) are available in the administrative record to assess this pollutant. Data from Pumping Plant D, which receives its water from Tule Lake, reflect zero of 16 samples exceeding the evaluation guideline for the protectino of COLD and MUN. Data from the Klamath Straits Drain at Stateline reflect zero of 16 samples exceed the evaluation guideline for the protetion of MUN. Data from the Klamath Straits Drain at Stateline reflect five of 16 samples exceed the evaluation guideline for the protection of COLD. 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. Data from the Klamath Straits Drain at Stateline reflect five of 16 samples exceed the evaluation guideline for the protection of COLD and this exceeds the allowable frequency listed in Table 4.1 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met. This listing applies only to the Klamath Straits Drain. This listing applies only to the Klamath Straits Drain.

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

State Board Review of Regional Board Conclusion and Recommendation:	This listing applies only to the Klamath Straits Drain.

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 168714, Mercury	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

122925

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

None of the 16 samples exceeded the objective of 2 ug/L. Sample values ranged from <0.1 ug/L to <0.2 ug/L.

Data Reference:

Data for pesticides collected by the Tule Lake Pesticide program, Apr. 2007-Oct. 2007 and data for metals and nutrients by the Klamath Water Quality program, Mar. 2006-Dec. 2009

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2011): Waters designated as domestic or municipal (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in Table 3-2 of the water quality control plan. The mercury MCL is 0.002 mg/L (2 ug/L).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from K-3 (Pumping Plant D).

Temporal Representation:

Samples were collected quarterly during the months of March, June, October, and December between the years 2006-2009.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 168714, Mercury	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

122924

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

None of the 16 samples exceeded the objective of 2 ug/L. Sample values ranged from <0.1 ug/L to 1.59 ug/L.

Data Reference:

Data for pesticides collected by the Tule Lake Pesticide program, Apr. 2007-Oct. 2007 and data for metals and nutrients by the Klamath Water Quality program, Mar. 2006-Dec. 2009

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

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

Guideline Reference:

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

Spatial Representation:

Samples were collected from K-2 (Klamath Straits Drain @ Stateline).

Temporal Representation:

Samples were collected quarterly during the months of March, June, October, and December between the years 2006-2009.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 168714, Mercury	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

32408

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

None of the 16 samples exceeded the evaluation guideline of 0.77 ug/L. Sample values ranged from <0.1 ug/L to <0.2 ug/L.

Data Reference:

Data for pesticides collected by the Tule Lake Pesticide program, Apr. 2007-Oct. 2007 and data for metals and nutrients by the Klamath Water Quality program, Mar. 2006-Dec. 2009

SWAMP Data:

Non-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:

National Recommended Water Quality Criteria Continuous Concentrations are intended protect freshwater aquatic organisms from chronic exposures and are expressed as 4-day average concentrations. Criterion are derived from data for inorganic mercury (II), but is applied to total mercury. The criteria for mercury is 0.77 ug/L.

Guideline Reference:

Spatial Representation:

Samples were collected from K-3 (Pumping Plant D).

Temporal Representation:

Samples were collected quarterly during the months of March, June, October, and December between the years 2006-2009

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Klamath Water Quality Quarterly Sampling. Quality Assurance Project Plan. USBR Mid-Pacific Region. Environmental Monitoring Branch, MP-157. April 22, 2008. Review number1.

Line of Evidence (LOE) for Decision ID 168714, Mercury	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

31676

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five (5) of the 16 samples exceeded the evaluation guideline of 0.77 ug/L. Sample values ranged from <0.1 ug/L to 1.59 ug/L.

Data Reference:

Data for pesticides collected by the Tule Lake Pesticide program, Apr. 2007-Oct. 2007 and data for metals and nutrients by the Klamath Water Quality program, Mar. 2006-Dec. 2009

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:

Samples were collected from K-2 (Klamath Straits Drain @ Stateline).

Temporal Representation:

Samples were collected quarterly during the months of March, June, October, and December between the years 2006-2009.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Klamath Water Quality Quarterly Sampling. Quality Assurance Project Plan. USBR Mid-Pacific Region. Environmental Monitoring Branch, MP-157. April 22, 2008. Review number1.


DECISION ID	158414	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

Pollutant:	Oxygen, Dissolved
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (being addressed by USEPA approved TMDL)(2018)
Revision Status	Revised
Sources:	Agricultural Return Flows \| Agriculture \| Agriculture-irrigation tailwater \| Internal Nutrient Cycling (primarily lakes) \| Natural Sources
TMDL Name:	Lower Lost River
TMDL Project Code:	99
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the CWA section 303(d) List under section 4.2 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. Twelve lines of evidence are available in the administrative record to assess this pollutant. ***For the COLD beneficial use, there are 6 LOEs and 39 of 151 samples exceed the guideline. For Klamath Straights Drain (LOEs 32874, 32887), there are two lines of evidence and 15 of 56 samples exceed the guideline. For Lost River (LOE 328896), there is one line of evidence and 13 of 48 samples exceed the guideline. For Pumping Plant D (LOE 32875), there is one line of evidence and 3 of 16 samples exceed the guideline. For Sheepy Ridge Pumping Station (LOE 328784), there is one line of evidence and 8 of 31 samples exceed the guideline. ***For the SPWN beneficial use, there are 3 LOEs and 54 of 119 samples exceed the guideline. For Klamath Straights Drain (LOE 328788), there is one line of evidence and 23 of 40 samples exceed the guideline. For Lost River (LOE 328877), there is one line of evidence and 18 of 48 samples exceed the guideline. For Sheepy Ridge Pumping Station (LOE 328824), there is one line of evidence and 13 of 31 samples exceed the guideline. ***For the WARM beneficial use, there are three lines of evidence and 23 of 119 samples exceed the guideline. For Klamath Straights Drain (LOE 328854), there is one line of evidence and 8 of 40 samples exceed the guideline. For Lost River (LOE 328817), there is one line of evidence and 9 of 48 samples exceed the guideline. For Sheepy Ridge Pumping Station (LOE 328873), there is one line of evidence and 6 of 31 samples exceed the guideline. 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 the COLD beneficial use, 39 of 151 samples exceed the guideline. For the SPWN beneficial use, 54 of 119 samples exceed the guideline. For the SPWN beneficial use, 54 of 119 samples exceed the guideline. All three of these exceed the allowable frequency listed in Table 4.2 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met. This listing applies to the entire waterbody. ***For the COLD beneficial use, there are 6 LOEs and 39 of 151 samples exceed the guideline. For Klamath Straights Drain (LOEs 32874, 32887), there are two lines of evidence and 15 of 56 samples exceed the guideline. For Lost River (LOE 328896), there is one line of evidence and 13 of 48 samples exceed the guideline. For Pumping Plant D (LOE 32875), there is one line of evidence and 3 of 16 samples exceed the guideline. For Sheepy Ridge Pumping Station (LOE 328784), there is one line of evidence and 8 of 31 samples exceed the guideline. ***For the SPWN beneficial use, there are 3 LOEs and 54 of 119 samples exceed the guideline. For Klamath Straights Drain (LOE 328788), there is one line of evidence and 23 of 40 samples exceed the guideline. For Lost River (LOE 328877), there is one line of evidence and 18 of 48 samples exceed the guideline. For Sheepy Ridge Pumping Station (LOE 328824), there is one line of evidence and 13 of 31 samples exceed the guideline. ***For the WARM beneficial use, there are three lines of evidence and 23 of 119 samples exceed the guideline. For Klamath Straights Drain (LOE 328854), there is one line of evidence and 8 of 40 samples exceed the guideline. For Lost River (LOE 328817), there is one line of evidence and 9 of 48 samples exceed the guideline. For Sheepy Ridge Pumping Station (LOE 328873), there is one line of evidence and 6 of 31 samples exceed the guideline. This listing applies to the entire waterbody.

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

State Board Review of Regional Board Conclusion and Recommendation:	***For the COLD beneficial use, there are 6 LOEs and 39 of 151 samples exceed the guideline. For Klamath Straights Drain (LOEs 32874, 32887), there are two lines of evidence and 15 of 56 samples exceed the guideline. For Lost River (LOE 328896), there is one line of evidence and 13 of 48 samples exceed the guideline. For Pumping Plant D (LOE 32875), there is one line of evidence and 3 of 16 samples exceed the guideline. For Sheepy Ridge Pumping Station (LOE 328784), there is one line of evidence and 8 of 31 samples exceed the guideline. ***For the SPWN beneficial use, there are 3 LOEs and 54 of 119 samples exceed the guideline. For Klamath Straights Drain (LOE 328788), there is one line of evidence and 23 of 40 samples exceed the guideline. For Lost River (LOE 328877), there is one line of evidence and 18 of 48 samples exceed the guideline. For Sheepy Ridge Pumping Station (LOE 328824), there is one line of evidence and 13 of 31 samples exceed the guideline. ***For the WARM beneficial use, there are three lines of evidence and 23 of 119 samples exceed the guideline. For Klamath Straights Drain (LOE 328854), there is one line of evidence and 8 of 40 samples exceed the guideline. For Lost River (LOE 328817), there is one line of evidence and 9 of 48 samples exceed the guideline. For Sheepy Ridge Pumping Station (LOE 328873), there is one line of evidence and 6 of 31 samples exceed the guideline. This listing applies to the entire waterbody.

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 158414, Oxygen, Dissolved	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

46845

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 Lower Lost River TMDL titled "Lost River, California Total Maximum Daily Loads: Nitrogen and Biochemical Oxygen Demand to address Dissolved Oxygen and pH Impairments" states that based upon a review of data, the Lost River (from Malone Dam in Oregon to the outlet at Klamath Straits Drain) is impaired for low dissolved oxygen (USEPA 2008, p.40). Nearly half of the samples from the Klamath Straits Drain fall below the dissolved oxygen objective.

Data Reference:

Lost River, California Total Maximum Daily Loads: Nitrogen and Biochemical Oxygen Demand to address Dissolved Oxygen and pH Impairments.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Per the Basin Plan (NCRWQCB 2011): The minimum level for dissolved oxygen in this water body is 5 mg/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The data were collected in the Tule Lake and Mount Dome HSAs.

Temporal Representation:

Data were collected during critical summer months (July - September) during the period from 1994 to 2004.

Environmental Conditions:

QAPP Information:

The data used in the USEPA TMDL is considered on adequate quality for Integrated Report purposes.

QAPP Information Reference(s):

Lost River, California Total Maximum Daily Loads: Nitrogen and Biochemical Oxygen Demand to address Dissolved Oxygen and pH Impairments.

Line of Evidence (LOE) for Decision ID 158414, Oxygen, Dissolved	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

328896

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 USGS California Water Science Center data for Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs to determine beneficial use support and results are as follows: 13 of 48 samples exceeded the water quality threshold for Oxygen, Dissolved.

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: USGS-11488495 (LOST R NR HATFIELD CA).

Temporal Representation:

The samples were collected between the dates of 2013-03-11 and 2015-03-24

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158414, Oxygen, Dissolved	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

328873

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:

Water Board staff assessed USGS California Water Science Center data for Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs to determine beneficial use support and results are as follows: 6 of 31 samples exceeded the water quality threshold for Oxygen, Dissolved.

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: USGS-11488510 (TULELAKE CN A SHEEPY RIDGE PUMPING STA NR HATFIELD).

Temporal Representation:

The samples were collected between the dates of 2013-03-11 and 2018-09-24

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158414, Oxygen, Dissolved	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

328854

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:

Water Board staff assessed USGS California Water Science Center data for Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs to determine beneficial use support and results are as follows: 8 of 40 samples exceeded the water quality threshold for Oxygen, Dissolved.

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: USGS-415950121463701 (KLAMATH STR DR A HY 161 NR DORRIS CA).

Temporal Representation:

The samples were collected between the dates of 2012-03-27 and 2018-04-02

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158414, Oxygen, Dissolved	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

328824

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 USGS California Water Science Center data for Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs to determine beneficial use support and results are as follows: 13 of 31 samples exceeded the water quality threshold for Oxygen, Dissolved.

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: USGS-11488510 (TULELAKE CN A SHEEPY RIDGE PUMPING STA NR HATFIELD).

Temporal Representation:

The samples were collected between the dates of 2013-03-11 and 2018-09-24

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158414, Oxygen, Dissolved	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

328784

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 USGS California Water Science Center data for Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs to determine beneficial use support and results are as follows: 8 of 31 samples exceeded the water quality threshold for Oxygen, Dissolved.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-11488510 (TULELAKE CN A SHEEPY RIDGE PUMPING STA NR HATFIELD).

Temporal Representation:

The samples were collected between the dates of 2013-03-11 and 2018-09-24

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158414, Oxygen, Dissolved	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

32875

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:

Three of the 16 samples had a dissolved oxygen level below 5 mg/L.

Data Reference:

Data for pesticides collected by the Tule Lake Pesticide program, Apr. 2007-Oct. 2007 and data for metals and nutrients by the Klamath Water Quality program, Mar. 2006-Dec. 2009

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Per the Basin Plan (NCRWQCB 2011): The minimum level for dissolved oxygen in this water body is 5 mg/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected at PPD- K-3 (Pumping Plant D).

Temporal Representation:

Samples were collected quarterly between 3/22/2006 and 12/7/2009.

Environmental Conditions:

QAPP Information:

Data included a Quality Assurance Project Plan titled 'Klamath Water Quality Quarterly Monitoring Quality Assurance Project Plan'.

QAPP Information Reference(s):

Klamath Water Quality Quarterly Sampling. Quality Assurance Project Plan. USBR Mid-Pacific Region. Environmental Monitoring Branch, MP-157. April 22, 2008. Review number1.

Line of Evidence (LOE) for Decision ID 158414, Oxygen, Dissolved	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

32874

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:

Six of the 16 samples had a dissolved oxygen level below 5 mg/L.

Data Reference:

Data for pesticides collected by the Tule Lake Pesticide program, Apr. 2007-Oct. 2007 and data for metals and nutrients by the Klamath Water Quality program, Mar. 2006-Dec. 2009

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Per the Basin Plan (NCRWQCB 2011): The minimum level for dissolved oxygen in this water body is 5 mg/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected at K-2 (Klamath Straits Drain @ Stateline).

Temporal Representation:

Samples were collected quarterly between 3/22/2006 and 12/7/2009.

Environmental Conditions:

QAPP Information:

Data included a Quality Assurance Project Plan titled 'Klamath Water Quality Quarterly Monitoring Quality Assurance Project Plan'.

QAPP Information Reference(s):

Klamath Water Quality Quarterly Sampling. Quality Assurance Project Plan. USBR Mid-Pacific Region. Environmental Monitoring Branch, MP-157. April 22, 2008. Review number1.

Line of Evidence (LOE) for Decision ID 158414, Oxygen, Dissolved	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

328788

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 USGS California Water Science Center data for Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs to determine beneficial use support and results are as follows: 23 of 40 samples exceeded the water quality threshold for Oxygen, Dissolved.

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: USGS-415950121463701 (KLAMATH STR DR A HY 161 NR DORRIS CA).

Temporal Representation:

The samples were collected between the dates of 2012-03-27 and 2018-04-02

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158414, Oxygen, Dissolved	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

328817

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:

Water Board staff assessed USGS California Water Science Center data for Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs to determine beneficial use support and results are as follows: 9 of 48 samples exceeded the water quality threshold for Oxygen, Dissolved.

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: USGS-11488495 (LOST R NR HATFIELD CA).

Temporal Representation:

The samples were collected between the dates of 2013-03-11 and 2015-03-24

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158414, Oxygen, Dissolved	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

328877

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 USGS California Water Science Center data for Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs to determine beneficial use support and results are as follows: 18 of 48 samples exceeded the water quality threshold for Oxygen, Dissolved.

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: USGS-11488495 (LOST R NR HATFIELD CA).

Temporal Representation:

The samples were collected between the dates of 2013-03-11 and 2015-03-24

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158414, Oxygen, Dissolved	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

328887

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 USGS California Water Science Center data for Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs to determine beneficial use support and results are as follows: 9 of 40 samples exceeded the water quality threshold for Oxygen, Dissolved.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-415950121463701 (KLAMATH STR DR A HY 161 NR DORRIS CA).

Temporal Representation:

The samples were collected between the dates of 2012-03-27 and 2018-04-02

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle


DECISION ID	168715	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

Pollutant:	Nutrients
Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)(2018)
Revision Status	Revised
Sources:	Agricultural Return Flows \| Agricultural Water Diversion \| Agriculture \| Agriculture-irrigation tailwater \| Agriculture-subsurface drainage \| Drainage/Filling Of Wetlands \| Habitat Modification \| Natural Sources \| Nonpoint Source \| Removal of Riparian Vegetation \| Specialty Crop Production \| Water Diversions
TMDL Name:	Lower Lost River
TMDL Project Code:	99
Date TMDL Approved by USEPA:	12/30/2008
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the section 303(d) list under section 4.1 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess the Cold Freshwater Habitat (COLD) beneficial use, and two lines of evidence are available to assess each of the Spawning, Reproduction, and/or Early Development (SPWN)and Municipal and Domestic Supply (MUN) beneficial uses. 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 section 303(d) list (i.e., sufficient justification to not delist). 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 32 samples exceed the SPWN ammonia evaluation guideline and this exceeds the allowable frequency listed in Table 4.1 of the Listing Policy. (4) Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met. This listing applies to the entire waterbody. This listing applies to the entire waterbody.

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

State Board Review of Regional Board Conclusion and Recommendation:	This listing applies to the entire waterbody.

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 168715, Nutrients	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

122927

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:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

None of the 16 samples exceed the water quality objective.

Data Reference:

Data for pesticides collected by the Tule Lake Pesticide program, Apr. 2007-Oct. 2007 and data for metals and nutrients by the Klamath Water Quality program, Mar. 2006-Dec. 2009

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Basin: Waters designated for MUN shall not contain concentrations of chemical constituents in excess of the MCL specified in Title 22 of the California Code of Regulations. The Nitrate/Nitrite as N MCL is 10 mg/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected at site K-3 (Pumping Plant D).

Temporal Representation:

Samples were collected from quarterly from March 2006 to December 2009.

Environmental Conditions:

QAPP Information:

Samples were collected as part of a monitoring program designed to determine baseline conditions of the water body. A unsigned QAPP was included with the data.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 168715, Nutrients	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

32389

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:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five of the 16 samples exceed the water quality objective.

Data Reference:

Data for pesticides collected by the Tule Lake Pesticide program, Apr. 2007-Oct. 2007 and data for metals and nutrients by the Klamath Water Quality program, Mar. 2006-Dec. 2009

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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 site K-3 (Pumping Plant D).

Temporal Representation:

Samples were collected from quarterly from March 2006 to December 2009.

Environmental Conditions:

QAPP Information:

Samples were collected as part of a monitoring program designed to determine baseline conditions of the water body. A unsigned QAPP was included with the data.

QAPP Information Reference(s):

Klamath Water Quality Quarterly Sampling. Quality Assurance Project Plan. USBR Mid-Pacific Region. Environmental Monitoring Branch, MP-157. April 22, 2008. Review number1.

Line of Evidence (LOE) for Decision ID 168715, Nutrients	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

3673

Pollutant:

Nutrients

LOE Subgroup:

Pollutant-Water

Matrix:

Not Specified

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:

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 168715, Nutrients	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

31716

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:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Two of the 16 samples exceed the evaluation guideline.

Data Reference:

Data for pesticides collected by the Tule Lake Pesticide program, Apr. 2007-Oct. 2007 and data for metals and nutrients by the Klamath Water Quality program, Mar. 2006-Dec. 2009

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:

1999 Update of Ambient Water Quality Criteria for Ammonia

Spatial Representation:

Samples were collected at site K-2 (Klamath Straits Drain at Stateline).

Temporal Representation:

Samples were collected from quarterly from March 2006 to December 2009.

Environmental Conditions:

QAPP Information:

Samples were collected as part of a monitoring program designed to determine baseline conditions of the water body. A unsigned QAPP was included with the data.

QAPP Information Reference(s):

Klamath Water Quality Quarterly Sampling. Quality Assurance Project Plan. USBR Mid-Pacific Region. Environmental Monitoring Branch, MP-157. April 22, 2008. Review number1.

Line of Evidence (LOE) for Decision ID 168715, Nutrients	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

122926

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:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

None of the 16 samples exceed the water quality objective.

Data Reference:

Data for pesticides collected by the Tule Lake Pesticide program, Apr. 2007-Oct. 2007 and data for metals and nutrients by the Klamath Water Quality program, Mar. 2006-Dec. 2009

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:

Samples were collected at site K-2 (Klamath Straits Drain at Stateline).

Temporal Representation:

Samples were collected from quarterly from March 2006 to December 2009.

Environmental Conditions:

QAPP Information:

Samples were collected as part of a monitoring program designed to determine baseline conditions of the water body. A unsigned QAPP was included with the data.

QAPP Information Reference(s):


DECISION ID	79038	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

Pollutant:	pH (high)
Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (being addressed by USEPA approved TMDL)(2016)
Revision Status	Revised
Sources:	Agricultural Return Flows \| Agriculture \| Agriculture-irrigation tailwater \| Internal Nutrient Cycling (primarily lakes) \| Natural Sources
TMDL Name:	Lower Lost River
TMDL Project Code:	99
Date TMDL Approved by USEPA:	12/30/2008
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Three lines of evidence are available in the administrative record to assess this pollutant. 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 section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: (1) The data used satisfies the data quality requirements of section 6.1.4 of the Policy. (2) The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. (3) Nine of 16 samples from Pumping Plant D (LOE 32409) exceed the pH objective and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. Additionally LOE 46831 describes the findings of the "Lost River, California Total Maximum Daily Loads: Nitrogen and Biochemical Oxygen Demand to address Dissolved Oxygen and pH Impairments", which confirms the impairments in the Tule Lake and Mt Dome HSAs. (4) Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. This listing applies to the entire waterbody., This listing applies to the entire waterbody.,

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

State Board Review of Regional Board Conclusion and Recommendation:	This listing applies to the entire waterbody.,

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 79038, pH (high)	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

46831

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 Lower Lost River TMDL titled "Lost River, California Total Maximum Daily Loads: Nitrogen and Biochemical Oxygen Demand to address Dissolved Oxygen and pH Impairments" states that pH impairments occur within the Tule Lake and Mount Dome HSAs, and specifically states that pH values in the upstream Klamath Straits Drain exceed the maximum pH objective.

Data Reference:

Lost River, California Total Maximum Daily Loads: Nitrogen and Biochemical Oxygen Demand to address Dissolved Oxygen and pH Impairments.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Per the Basin Plan (NCRWQCB 2011): The maximum pH objective is 9.0. The minimum pH objective is 7.0.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The data were collected in the Tule Lake and Mount Dome HSAs.

Temporal Representation:

Data were collected during critical summer months (July - September) during the period from 1994 to 2004.

Environmental Conditions:

QAPP Information:

The data used in the USEPA TMDL is considered on adequate quality for Integrated Report purposes.

QAPP Information Reference(s):

Lost River, California Total Maximum Daily Loads: Nitrogen and Biochemical Oxygen Demand to address Dissolved Oxygen and pH Impairments.

Line of Evidence (LOE) for Decision ID 79038, pH (high)	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

32059

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:

Two of the 16 samples had a pH above the objective of 9. Sample values ranged from 7.36 to 9.24.

Data Reference:

Data for pesticides collected by the Tule Lake Pesticide program, Apr. 2007-Oct. 2007 and data for metals and nutrients by the Klamath Water Quality program, Mar. 2006-Dec. 2009

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Per the Basin Plan (NCRWQCB 2011): The maximum pH objective is 9. The minimum pH objective is 7.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected at K-2 (Klamath Straits Drain @ Stateline).

Temporal Representation:

Samples were collected quarterly between 3/22/2006 and 12/7/2009.

Environmental Conditions:

QAPP Information:

Data included a Quality Assurance Project Plan titled 'Klamath Water Quality Quarterly Monitoring Quality Assurance Project Plan'.

QAPP Information Reference(s):

Klamath Water Quality Quarterly Sampling. Quality Assurance Project Plan. USBR Mid-Pacific Region. Environmental Monitoring Branch, MP-157. April 22, 2008. Review number1.

Line of Evidence (LOE) for Decision ID 79038, pH (high)	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

32409

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Nine of the 16 samples exceeded the pH objective of 9. Samples ranged from 8.19 to 9.85.

Data Reference:

Data for pesticides collected by the Tule Lake Pesticide program, Apr. 2007-Oct. 2007 and data for metals and nutrients by the Klamath Water Quality program, Mar. 2006-Dec. 2009

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Per the Basin Plan (NCRWQCB 2011): The maximum pH objective is 9. The minimum pH objective is 7.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected at K-3 (Pumping Plant D).

Temporal Representation:

Samples were collected quarterly between 3/22/2006 and 12/7/2009.

Environmental Conditions:

QAPP Information:

Data included a Quality Assurance Project Plan titled 'Klamath Water Quality Quarterly Monitoring Quality Assurance Project Plan'.

QAPP Information Reference(s):

Klamath Water Quality Quarterly Sampling. Quality Assurance Project Plan. USBR Mid-Pacific Region. Environmental Monitoring Branch, MP-157. April 22, 2008. Review number1.


DECISION ID	79109	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

Pollutant:	Boron
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Four lines of evidence are available in the administrative record to assess this pollutant. Zero of 16 samples from the Klamath Straits Drain and Pumping Plant D (which drains Tule Lake) exceed the objective for the protection of the MUN and AGR beneficial uses. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of 16 samples from the Klamath Straits Drain and Pumping Plant D (which drains Tule Lake) exceed the objective for the protection of the MUN and AGR beneficial uses and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 79109, Boron	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

122923

Pollutant:

Boron

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

None of the 16 samples analyzed exceeded the evaluation guideline of 1000 ug/L. Sample values ranged from 10 ug/L to 150 ug/L.

Data Reference:

Data for pesticides collected by the Tule Lake Pesticide program, Apr. 2007-Oct. 2007 and data for metals and nutrients by the Klamath Water Quality program, Mar. 2006-Dec. 2009

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

Notification levels (formerly called "action levels")are published by the California Department of Public Health (CDPH) for chemicals for which there is no drinking water MCL. Notification levels are based mainly on health effects -- in most cases an incremental cancer risk estimate of 10(-6) for carcinogens and a threshold toxicity limit for other constituents. As with MCLs, the ability to quantify the amount of the constituent in a water sample using readily available analytical methods may cause notification levels to be set at somewhat higher concentrations than purely health-based values. Notification levels are advisory to water suppliers. If a notification level is exceeded, local government notification is required and customer notification is recommended. At a higher level, called the response level, the drinking water source is recommended to be taken out of service. The criteria for boron is 1000 ug/L (1 mg/L).

Guideline Reference:

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

Spatial Representation:

Samples were collected from K-3 (Pumping Plant D).

Temporal Representation:

Samples were collected quarterly during the months of March, June, October, and December between the years 2006-2009

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 79109, Boron	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

122918

Pollutant:

Boron

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

None of the 16 samples analyzed exceeded the evaluation guideline of 1000 ug/L. Sample values ranged from 140 ug/L to 540 ug/L.

Data Reference:

Data for pesticides collected by the Tule Lake Pesticide program, Apr. 2007-Oct. 2007 and data for metals and nutrients by the Klamath Water Quality program, Mar. 2006-Dec. 2009

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:

Samples were collected from K-2 (Klamath Straits Drain @ Stateline).

Temporal Representation:

Samples were collected quarterly during the months of March, June, October, and December between the years 2006-2009.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 79109, Boron	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

32407

Pollutant:

Boron

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Agricultural Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

None of the 16 samples exceeded the evaluation guideline of 700 ug/L. Sample values ranged from 10 ug/L to 150 ug/L.

Data Reference:

Data for pesticides collected by the Tule Lake Pesticide program, Apr. 2007-Oct. 2007 and data for metals and nutrients by the Klamath Water Quality program, Mar. 2006-Dec. 2009

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Basin (NCRWQCB 2011): Waters designated for use as agricultural supply (AGR) shall not contain concentrations of chemical constituents in amounts which adversely affect such beneficial use.

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 limits presented in the Water Quality Goals tables, agricultural uses of water should not be limited. These criteria were used to translate narrative water quality objectives for chemical constituents that prohibit chemicals in concentrations that would impair agricultural uses of water. The criteria for boron is 700 ug/L (0.7 mg/L).

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:

Samples were collected from K-3 (Pumping Plant D).

Temporal Representation:

Samples were collected quarterly during the months of March, June, October, and December between the years 2006-2009.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Klamath Water Quality Quarterly Sampling. Quality Assurance Project Plan. USBR Mid-Pacific Region. Environmental Monitoring Branch, MP-157. April 22, 2008. Review number1.

Line of Evidence (LOE) for Decision ID 79109, Boron	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

31675

Pollutant:

Boron

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Agricultural Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

None of the 16 samples analyzed exceeded the evaluation guideline of 700 ug/L. Sample values ranged from 140 ug/L to 540 ug/L.

Data Reference:

Data for pesticides collected by the Tule Lake Pesticide program, Apr. 2007-Oct. 2007 and data for metals and nutrients by the Klamath Water Quality program, Mar. 2006-Dec. 2009

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:

Samples were collected from K-2 (Klamath Straits Drain @ Stateline).

Temporal Representation:

Samples were collected quarterly during the months of March, June, October, and December between the years 2006-2009.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Klamath Water Quality Quarterly Sampling. Quality Assurance Project Plan. USBR Mid-Pacific Region. Environmental Monitoring Branch, MP-157. April 22, 2008. Review number1.


DECISION ID	158413	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 158413, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

328666

Pollutant:

Nitrate/Nitrite (Nitrite + Nitrate as N)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed USGS California Water Science Center data for Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs to determine beneficial use support and results are as follows: 0 of 16 samples exceeded the water quality threshold for Nitrate + Nitrite as N.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-11488510 (TULELAKE CN A SHEEPY RIDGE PUMPING STA NR HATFIELD).

Temporal Representation:

The samples were collected between the dates of 2013-05-21 and 2017-03-07

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158413, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

328643

Pollutant:

Nitrate/Nitrite (Nitrite + Nitrate as N)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed USGS California Water Science Center data for Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs to determine beneficial use support and results are as follows: 0 of 19 samples exceeded the water quality threshold for Nitrate + Nitrite as N.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-415950121463701 (KLAMATH STR DR A HY 161 NR DORRIS CA).

Temporal Representation:

The samples were collected between the dates of 2013-01-02 and 2018-04-02

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158413, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

328663

Pollutant:

Nitrate/Nitrite (Nitrite + Nitrate as N)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed USGS California Water Science Center data for Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs to determine beneficial use support and results are as follows: 0 of 37 samples exceeded the water quality threshold for Nitrate + Nitrite as N.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-11488495 (LOST R NR HATFIELD CA).

Temporal Representation:

The samples were collected between the dates of 2013-03-26 and 2015-02-24

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle


DECISION ID	163023	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

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:	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. Five lines of evidence are available in the administrative record to assess this pollutant. FOR THE COLD FRESHWATER HABITAT BENEFICIAL USE: KLAMATH STRAITS DRAIN has one LOE (318874) and 4 of 4 samples exceed the objective; LOST RIVER has one LOE (318883) and 1 of 3 samples exceed the objective; TULELAKE CANYON DRAIN has one LOE (319020) and 0 of 6 samples exceed the objective. FOR THE MUNICIPAL & DOMESTIC SUPPLY BENEFICIAL USE: KLAMATH STRAITS DRAIN has one LOE (122933) and 2 of 4 samples exceed the objective and PUMPING PLANT D has one LOE (122932) and 0 of 4 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. FOR THE COLD FRESHWATER HABITAT BENEFICIAL USE: KLAMATH STRAITS DRAIN has one LOE (318874) and 4 of 4 samples exceed the objective; LOST RIVER has one LOE (318883) and 1 of 3 samples exceed the objective; TULELAKE CANYON DRAIN has one LOE (319020) and 0 of 6 samples exceed the objective. FOR THE MUNICIPAL & DOMESTIC SUPPLY BENEFICIAL USE: KLAMATH STRAITS DRAIN has one LOE (122933) and 2 of 4 samples exceed the objective and PUMPING PLANT D has one LOE (122932) and 0 of 4 samples exceed the objective. This does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. **FOR THE COLD FRESHWATER HABITAT BENEFICIAL USE: KLAMATH STRAITS DRAIN has one LOE (318874) and 4 of 4 samples exceed the objective. LOST RIVER has one LOE (318883) and 1 of 3 samples exceed the objective. TULELAKE CANYON DRAIN has one LOE (319020) and 0 of 6 samples exceed the objective. **FOR THE MUNICIPAL & DOMESTIC SUPPLY BENEFICIAL USE: KLAMATH STRAITS DRAIN has one LOE (122933) and 2 of 4 samples exceed the objective. *PUMPING PLANT D has one LOE (122932) and 0 of 4 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 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:	**FOR THE COLD FRESHWATER HABITAT BENEFICIAL USE: KLAMATH STRAITS DRAIN has one LOE (318874) and 4 of 4 samples exceed the objective. LOST RIVER has one LOE (318883) and 1 of 3 samples exceed the objective. TULELAKE CANYON DRAIN has one LOE (319020) and 0 of 6 samples exceed the objective. **FOR THE MUNICIPAL & DOMESTIC SUPPLY BENEFICIAL USE: KLAMATH STRAITS DRAIN has one LOE (122933) and 2 of 4 samples exceed the objective. *PUMPING PLANT D has one LOE (122932) and 0 of 4 samples exceed the objective.

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 163023, Specific Conductivity	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

122932

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 4 calendar years exceeded the objective.

Data Reference:

Data for pesticides collected by the Tule Lake Pesticide program, Apr. 2007-Oct. 2007 and data for metals and nutrients by the Klamath Water Quality program, Mar. 2006-Dec. 2009

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Per the Basin Plan (NCRWQCB 2011): 50% or more of the monthly means for a calendar year must be less than or equal to 900 micromhos, and 90% or more of the monthly means for a calendar year must be less than or equal to 1300 micromhos.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected at K-3 (Pumping Plant D).

Temporal Representation:

Samples were collected quarterly between 3/22/2006 and 12/7/2009.

Environmental Conditions:

QAPP Information:

Data included a Quality Assurance Project Plan titled 'Klamath Water Quality Quarterly Monitoring Quality Assurance Project Plan'.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 163023, Specific Conductivity	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

122933

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data in two of four calendar years exceeded the Basin Plan Objective. In 2006 and 2007 only 75% of the samples were less than 1150 micromhos, which violates the objective. Additionally, in 2007, only 25% of samples were less than 850 micromhos, which violates the objective. In 2008 and 2009 the Basin Plan objective for specific conductance was not violated.

Data Reference:

Data for pesticides collected by the Tule Lake Pesticide program, Apr. 2007-Oct. 2007 and data for metals and nutrients by the Klamath Water Quality program, Mar. 2006-Dec. 2009

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Per the Basin Plan (NCRWQCB 2011): 50% or more of the monthly means for a calendar year must be less than or equal to 850 micromhos, and 90% or more of the monthly means for a calendar year must be less than or equal to 1150 micromhos.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected at K-2 (Klamath Straits Drain @ Stateline).

Temporal Representation:

Samples were collected quarterly between 3/22/2006 and 12/7/2009.

Environmental Conditions:

QAPP Information:

Data included a Quality Assurance Project Plan titled 'Klamath Water Quality Quarterly Monitoring Quality Assurance Project Plan'.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 163023, Specific Conductivity	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

318883

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed specific conductivity data for USGS California Water Science Center and determined that calendar years 2013 and 2014 do not exceed either the 90% or 50% upper limit and calendar year 2015 exceeds the 50% upper limit, so that 1 of 3 samples exceed the water quality objective.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Per the Basin Plan (NCRWQCB 2007): The 90% upper limit specific conductance objective at 77 F is 1000 micromhos (or mS/cm2). The 50% upper limit specific conductance objective at 77 F is 700 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: LOST R NR HATFIELD CA; station code: USGS-11488495.

Temporal Representation:

These samples were collected from 3/11/2013-3/24/2015.

Environmental Conditions:

QAPP Information:

QAPP for USGS California Water Science Center

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 163023, Specific Conductivity	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

319020

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed specific conductivity data for USGS California Water Science Center and determined that calendar years 2013, 2014, 2015, 2016, 2017, and 2018 do not exceed either the 90% or 50% upper limit, so that 0 of 6 samples exceed the water quality objective.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Per the Basin Plan (NCRWQCB 2007): The 90% upper limit specific conductance objective at 77 F is 300 micromhos (or mS/cm2). The 50% upper limit specific conductance objective at 77 F is 150 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: TULELAKE CN A SHEEPY RIDGE PUMPING STA NR HATFIELD; USGS-11488510.

Temporal Representation:

These samples were collected from 3/11/2013-9/24/2018.

Environmental Conditions:

QAPP Information:

QAPP for USGS California Water Science Center

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 163023, Specific Conductivity	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

318874

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed specific conductivity data for USGS California Water Science Center and determined that calendar years 2012, 2013, 2017, and 2018 exceed both the 905 and 50% upper limits, so that 4 of 4 samples exceed the water quality objective.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Per the Basin Plan (NCRWQCB 2007): The 90% upper limit specific conductance objective at 77 F is 250 micromhos (or mS/cm2). The 50% upper limit specific conductance objective at 77 F is 150 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 the sampling station name: KLAMATH STR DR A HY 161 NR DORRIS CA; station code: USGS-415950121463701.

Temporal Representation:

These samples were collected from 3/27/2012-4/2/2018.

Environmental Conditions:

QAPP Information:

QAPP for USGS California Water Science Center

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle


DECISION ID	158412	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Four lines of evidence are available in the administrative record to assess this pollutant. Six of ten samples exceed the Warm Freshwater Habitat beneficial use objective and six of ten 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 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. Six of ten samples exceed the Warm Freshwater Habitat beneficial use objective and six of ten samples exceed the Cold Freshwater Habitat beneficial use objective, and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. This listing only applies to the Tulelake Canyon drain. **FOR THE COLD BENEFICIAL USE: KLAMATH STRAITS DRAIN has one LOE (328223) and 1 of 2 samples exceed the objective. TULELAKE CANYON DRAIN has one LOE (328232) and 5 of 8 samples exceed the objective. *FOR THE WARM BENEFICIAL USE: KLAMATH STRAITS DRAIN has one LOE (328207) and 1 of 2 samples exceed the objective. *TULELAKE CANYON DRAIN has one LOE (328222) and 5 of 8 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:	**FOR THE COLD BENEFICIAL USE: KLAMATH STRAITS DRAIN has one LOE (328223) and 1 of 2 samples exceed the objective. TULELAKE CANYON DRAIN has one LOE (328232) and 5 of 8 samples exceed the objective. *FOR THE WARM BENEFICIAL USE: KLAMATH STRAITS DRAIN has one LOE (328207) and 1 of 2 samples exceed the objective. *TULELAKE CANYON DRAIN has one LOE (328222) and 5 of 8 samples exceed the objective.

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 158412, Chlorophyll-a	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

328222

Pollutant:

Chlorophyll-a

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed USGS California Water Science Center data for Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs to determine beneficial use support and results are as follows: 5 of 8 samples exceeded the water quality threshold for Chlorophyll a.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses. (Basin Plan, 2018)

Objective/Criterion Reference:

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

Evaluation Guideline:

North Carolina Administrative code (NCAC), Title 15ANAEnvironmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.

Guideline Reference:

North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-11488510 (TULELAKE CN A SHEEPY RIDGE PUMPING STA NR HATFIELD).

Temporal Representation:

The samples were collected between the dates of 2016-02-18 and 2018-09-24

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158412, Chlorophyll-a	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

328207

Pollutant:

Chlorophyll-a

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed USGS California Water Science Center data for Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs to determine beneficial use support and results are as follows: 1 of 2 samples exceeded the water quality threshold for Chlorophyll a.

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:

North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-415950121463701 (KLAMATH STR DR A HY 161 NR DORRIS CA).

Temporal Representation:

The samples were collected between the dates of 2017-03-24 and 2018-04-02

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158412, Chlorophyll-a	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

328232

Pollutant:

Chlorophyll-a

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed USGS California Water Science Center data for Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs to determine beneficial use support and results are as follows: 5 of 8 samples exceeded the water quality threshold for Chlorophyll a.

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:

North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-11488510 (TULELAKE CN A SHEEPY RIDGE PUMPING STA NR HATFIELD).

Temporal Representation:

The samples were collected between the dates of 2016-02-18 and 2018-09-24

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158412, Chlorophyll-a	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

328223

Pollutant:

Chlorophyll-a

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed USGS California Water Science Center data for Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs to determine beneficial use support and results are as follows: 1 of 2 samples exceeded the water quality threshold for Chlorophyll a.

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:

North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-415950121463701 (KLAMATH STR DR A HY 161 NR DORRIS CA).

Temporal Representation:

The samples were collected between the dates of 2017-03-24 and 2018-04-02

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle


DECISION ID	158415	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

Pollutant:	Temperature, water
Final Listing Decision:	List on 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
Sources:	A Source Unknown
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the CWA section 303(d) List under section 4.2 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. Seven lines of evidence are available in the administrative record to assess this pollutant. *LIST* For KLAMATH STRAIGHTS DRAIN (LOEs 32609, 329317), 10 of 56 samples exceed the cold freshwater habitat beneficial use objective. *DO NOT LIST - FULLY SUPPPORTING* For LOST RIVER (LOEs 32606, 329304), 9 of 72 samples exceed the cold freshwater habitat beneficial use objective. *DO NOT LIST - INSUFFICIENT INFORMATION* For TULE LAKE DISCHARGE, PUMPING PLANT D (LOE 32608), 0 of 16 samples exceed the cold freshwater habitat beneficial use objective. For TULE LAKE DISCHARGE, SHEEPY RIDGE PUMPING STATION, 3 of 31 samples exceed the cold freshwater habitat beneficial use objective. For KLAMATH RIVER HU, LOST RIVER HA, TULE LAKE AND MT DOME HSAs (LOE 1658), there is insufficient data to determine support of the warm 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 KLAMATH STRAIGHTS DRAIN (LOEs 32609, 329317), 10 of 56 samples exceed the cold freshwater habitat beneficial use objective and this exceeds the allowable frequency listed in Table 4.2 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 158415, Temperature, water	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

329317

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 USGS California Water Science Center data for Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs to determine beneficial use support and results are as follows: 10 of 40 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:

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:

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:

The samples were collected at 1 monitoring site: USGS-415950121463701 (KLAMATH STR DR A HY 161 NR DORRIS CA).

Temporal Representation:

The samples were collected between the dates of 2012-03-27 and 2018-04-02

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158415, Temperature, water	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

329304

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 USGS California Water Science Center data for Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs to determine beneficial use support and results are as follows: 8 of 48 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: USGS-11488495 (LOST R NR HATFIELD CA).

Temporal Representation:

The samples were collected between the dates of 2013-03-11 and 2015-03-24

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158415, Temperature, water	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

32609

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:

Zero of sixteen (16) samples from the Klamath Straits Drain exceeded the evaluation guideline. The sample values ranged from 3.9 degrees C to 25.8 degrees C.

Data Reference:

Data for pesticides collected by the Tule Lake Pesticide program, Apr. 2007-Oct. 2007 and data for metals and nutrients by the Klamath Water Quality program, Mar. 2006-Dec. 2009

SWAMP Data:

Non-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. Additionally, the "Water Quality Control Plan for Control of Temperature in the Coastal and Interstate Waters and Enclosed Bays and Estuaries of California" (Thermal Plan) objective for COLD applies as follows: elevated temperature waste discharges into cold interstate waters are prohibited.

Objective/Criterion Reference:

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

Evaluation Guideline:

The LC50 temperature threshold for suckers is 30.3 degrees C (NCRWBCB 2004).

Guideline Reference:

Total daily maximum load analysis-water temperature and nutrients. Upper Lost River and Clear Lake Reservoir Watershed. Santa Rosa, CA: North Coast RWQCB

Spatial Representation:

Grab samples were collected from K-2 (Klamath Straits Drain @ Stateline).

Temporal Representation:

Grab samples were collected quarterly between 3/22/2006 and 12/7/2009.

Environmental Conditions:

QAPP Information:

Data included a Quality Assurance Project Plan titled 'Klamath Water Quality Quarterly Monitoring Quality Assurance Project Plan'.

QAPP Information Reference(s):

Klamath Water Quality Quarterly Sampling. Quality Assurance Project Plan. USBR Mid-Pacific Region. Environmental Monitoring Branch, MP-157. April 22, 2008. Review number1.

Line of Evidence (LOE) for Decision ID 158415, Temperature, water	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

32608

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:

Zero of sixteen (16) samples from the Pumping Plant D site which drains water from Tule Lake exceeded the evaluation guideline. The sample values ranged from 2.4 degrees C to 20.3 degrees C.

Data Reference:

Data for pesticides collected by the Tule Lake Pesticide program, Apr. 2007-Oct. 2007 and data for metals and nutrients by the Klamath Water Quality program, Mar. 2006-Dec. 2009

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 LC50 temperature threshold for suckers is 30.3 degrees C (NCRWBCB 2004).

Guideline Reference:

Total daily maximum load analysis-water temperature and nutrients. Upper Lost River and Clear Lake Reservoir Watershed. Santa Rosa, CA: North Coast RWQCB

Spatial Representation:

Grab samples were collected from K-3 (Pumping Plant D).

Temporal Representation:

Grab samples were collected quarterly between 3/22/2006 and 12/7/2009.

Environmental Conditions:

QAPP Information:

Data included a Quality Assurance Project Plan titled 'Klamath Water Quality Quarterly Monitoring Quality Assurance Project Plan'.

QAPP Information Reference(s):

Klamath Water Quality Quarterly Sampling. Quality Assurance Project Plan. USBR Mid-Pacific Region. Environmental Monitoring Branch, MP-157. April 22, 2008. Review number1.

Line of Evidence (LOE) for Decision ID 158415, Temperature, water	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

329295

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 USGS California Water Science Center data for Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs to determine beneficial use support and results are as follows: 3 of 31 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: USGS-11488510 (TULELAKE CN A SHEEPY RIDGE PUMPING STA NR HATFIELD).

Temporal Representation:

The samples were collected between the dates of 2013-03-11 and 2018-09-24

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158415, Temperature, water	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

1658

Pollutant:

Temperature, water

LOE Subgroup:

Narrative Description Data

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

There was no site specific data or information to support the temperature listing for this water body. EPA's temperature listings for North Coast rivers in 1992 were based on evidence of salmonid habitat degradation due to elevated temperature conditions that did not specifically reference impairments in this water body. As this water body does not support salmonid habitat and the 1992 listing record does not support a finding of temperature impairment, this listing was in error. Review of the recent temperature data for this water body indicates there is insufficient evidence of temperature impairment to support this listing.

Data Reference:

Placeholder reference 2006 303(d)

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

Environmental Conditions:

QAPP Information:

QA Info Missing

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158415, Temperature, water	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

32606

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:

Zero of twenty-four (24) samples from the Lost River exceeded the evaluation guideline. The sample values ranged from 8.7 degrees C to 25.6 degrees C.

Data Reference:

Data for pesticides collected by the Tule Lake Pesticide program, Apr. 2007-Oct. 2007 and data for metals and nutrients by the Klamath Water Quality program, Mar. 2006-Dec. 2009

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 LC50 temperature threshold for suckers is 30.3 degrees C (NCRWBCB 2004).

Guideline Reference:

Total daily maximum load analysis-water temperature and nutrients. Upper Lost River and Clear Lake Reservoir Watershed. Santa Rosa, CA: North Coast RWQCB

Spatial Representation:

Grab samples were collected at varying depths (2 depths per date/location) from the Lost River @ East West Bridge (LREW).

Temporal Representation:

Grab samples were collected between 4/30/2007 and 10/22/2007.

Environmental Conditions:

QAPP Information:

Data included a Quality Assurance Project Plan titled 'Tule Lake Pesticide Monitoring 2007 Quality Assurance Project Plan'.

QAPP Information Reference(s):

Quality Assurance Project Plan for Tule Lake Pesticide Monitoring 2007.


DECISION ID	158416	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Three lines of evidence are available in the administrative record to assess this pollutant. Fifty-three of 63 samples exceed the objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Fifty-three of 63 samples exceed the objective and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. This listing applies to the entire waterbody. KLAMATH STRAITS DRAIN has one LOE (329344) and 12 of 14 samples exceed the objective. TULELAKE CANYON DRAIN has one LOE (329369) and 16 of 16 samples exceed the objective. LOST RIVER has one LOE (329364) and 25 of 33 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:	KLAMATH STRAITS DRAIN has one LOE (329344) and 12 of 14 samples exceed the objective. TULELAKE CANYON DRAIN has one LOE (329369) and 16 of 16 samples exceed the objective. LOST RIVER has one LOE (329364) and 25 of 33 samples exceed the objective.

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 158416, Turbidity	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

329344

Pollutant:

Turbidity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed USGS California Water Science Center data for Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs to determine beneficial use support and results are as follows: 12 of 14 samples exceeded the water quality threshold for Turbidity.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15, Division 4, Article 4, Section 64435 (Tables 2 and 3), and Section 64444.5 (Table 5), and listed in Table 3-2 of this Plan (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

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

Evaluation Guideline:

California Maximum Contaminant Levels (MCLs) apply to ambient surface waters under the Basin Plan's 'Chemical Constituents' objective. The Secondary MCL for turbidity is 5 NTU. Calculation of a numeric objective for other beneficial uses requires comparison with upstream or other background data which may not be available as part of the data used for water quality assessment.

Guideline Reference:

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

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-415950121463701 (KLAMATH STR DR A HY 161 NR DORRIS CA).

Temporal Representation:

The samples were collected between the dates of 2013-03-11 and 2013-09-10

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158416, Turbidity	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

329364

Pollutant:

Turbidity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed USGS California Water Science Center data for Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs to determine beneficial use support and results are as follows: 25 of 33 samples exceeded the water quality threshold for Turbidity.

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: USGS-11488495 (LOST R NR HATFIELD CA).

Temporal Representation:

The samples were collected between the dates of 2013-03-11 and 2014-08-26

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 158416, Turbidity	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

329369

Pollutant:

Turbidity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed USGS California Water Science Center data for Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs to determine beneficial use support and results are as follows: 16 of 16 samples exceeded the water quality threshold for Turbidity.

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: USGS-11488510 (TULELAKE CN A SHEEPY RIDGE PUMPING STA NR HATFIELD).

Temporal Representation:

The samples were collected between the dates of 2013-03-11 and 2013-10-22

Environmental Conditions:

QAPP Information:

QAPP not required for USGS projects

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle


DECISION ID	168716	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Three lines of evidence are available in the administrative record to assess this pollutant. Eleven of the 32 samples exceed the objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Eleven of the 32 samples exceed the objective and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. This listing applies to the entire waterbody. KLAMATH STRAITS DRAIN has two LOEs (32059, 46831) and 2 of 16 samples exceed the objective, and the The Lower Lost River TMDL titled "Lost River, California Total Maximum Daily Loads: Nitrogen and Biochemical Oxygen Demand to address Dissolved Oxygen and pH Impairments" states that pH impairments occur within the Tule Lake and Mount Dome HSAs, and specifically states that pH values in the upstream Klamath Straits Drain exceed the maximum pH objective. PUMPING PLANT D has one LOE (32409) and 9 of 16 samples exceed the objective.

Regional Board Decision Recommendation:	This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.

State Board Review of Regional Board Conclusion and Recommendation:	KLAMATH STRAITS DRAIN has two LOEs (32059, 46831) and 2 of 16 samples exceed the objective, and the The Lower Lost River TMDL titled "Lost River, California Total Maximum Daily Loads: Nitrogen and Biochemical Oxygen Demand to address Dissolved Oxygen and pH Impairments" states that pH impairments occur within the Tule Lake and Mount Dome HSAs, and specifically states that pH values in the upstream Klamath Straits Drain exceed the maximum pH objective. PUMPING PLANT D has one LOE (32409) and 9 of 16 samples exceed the objective.

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 168716, pH	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

32409

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Nine of the 16 samples exceeded the pH objective of 9. Samples ranged from 8.19 to 9.85.

Data Reference:

Data for pesticides collected by the Tule Lake Pesticide program, Apr. 2007-Oct. 2007 and data for metals and nutrients by the Klamath Water Quality program, Mar. 2006-Dec. 2009

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Per the Basin Plan (NCRWQCB 2011): The maximum pH objective is 9. The minimum pH objective is 7.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected at K-3 (Pumping Plant D).

Temporal Representation:

Samples were collected quarterly between 3/22/2006 and 12/7/2009.

Environmental Conditions:

QAPP Information:

Data included a Quality Assurance Project Plan titled 'Klamath Water Quality Quarterly Monitoring Quality Assurance Project Plan'.

QAPP Information Reference(s):

Klamath Water Quality Quarterly Sampling. Quality Assurance Project Plan. USBR Mid-Pacific Region. Environmental Monitoring Branch, MP-157. April 22, 2008. Review number1.

Line of Evidence (LOE) for Decision ID 168716, pH	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

46831

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 Lower Lost River TMDL titled "Lost River, California Total Maximum Daily Loads: Nitrogen and Biochemical Oxygen Demand to address Dissolved Oxygen and pH Impairments" states that pH impairments occur within the Tule Lake and Mount Dome HSAs, and specifically states that pH values in the upstream Klamath Straits Drain exceed the maximum pH objective.

Data Reference:

Lost River, California Total Maximum Daily Loads: Nitrogen and Biochemical Oxygen Demand to address Dissolved Oxygen and pH Impairments.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Per the Basin Plan (NCRWQCB 2011): The maximum pH objective is 9.0. The minimum pH objective is 7.0.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The data were collected in the Tule Lake and Mount Dome HSAs.

Temporal Representation:

Data were collected during critical summer months (July - September) during the period from 1994 to 2004.

Environmental Conditions:

QAPP Information:

The data used in the USEPA TMDL is considered on adequate quality for Integrated Report purposes.

QAPP Information Reference(s):

Lost River, California Total Maximum Daily Loads: Nitrogen and Biochemical Oxygen Demand to address Dissolved Oxygen and pH Impairments.

Line of Evidence (LOE) for Decision ID 168716, pH	Region 1
Klamath River HU, Lost River HA, Tule Lake and Mt Dome HSAs

LOE ID:

32059

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:

Two of the 16 samples had a pH above the objective of 9. Sample values ranged from 7.36 to 9.24.

Data Reference:

Data for pesticides collected by the Tule Lake Pesticide program, Apr. 2007-Oct. 2007 and data for metals and nutrients by the Klamath Water Quality program, Mar. 2006-Dec. 2009

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Per the Basin Plan (NCRWQCB 2011): The maximum pH objective is 9. The minimum pH objective is 7.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected at K-2 (Klamath Straits Drain @ Stateline).

Temporal Representation:

Samples were collected quarterly between 3/22/2006 and 12/7/2009.

Environmental Conditions:

QAPP Information:

Data included a Quality Assurance Project Plan titled 'Klamath Water Quality Quarterly Monitoring Quality Assurance Project Plan'.

QAPP Information Reference(s):

Klamath Water Quality Quarterly Sampling. Quality Assurance Project Plan. USBR Mid-Pacific Region. Environmental Monitoring Branch, MP-157. April 22, 2008. Review number1.