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

Supporting Information

Regional Board 8 - Santa Ana Region

Water Body Name:	Mountain Home Creek, East Fork
Water Body ID:	CAR8015800019990211111904
Water Body Type:	River & Stream


DECISION ID	149161	Region 8
Mountain Home Creek, East Fork

Pollutant:	Indicator Bacteria
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:	Medium
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the CWA section 303(d) List under sections 4.2 and 4.3 of the Listing Policy. Under these sections a single line of evidence is necessary to assess listing status. The State Water Board’s Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California (the “ISWEBE Plan”) contains two bacteria water quality objectives applicable to the REC-1 beneficial use, which were adopted on August 7, 2018. Because the salinity level of this waterbody is equal to or less than 1 part per thousand 95 percent or more of the time, the E. coli bacteria objective applies. Therefore, this waterbody is being considered for removal from the CWA section 303(d) List under section 4.3 of the Listing Policy using the E. coli objective. Three (3) lines of evidence are available in the administrative record to assess this pollutant for the REC-1 beneficial use. Zero (0) of 5 samples exceed the 6-week E.coli Geomean objective. Zero (0) of 6 samples exceed the E.coli Statistical Threshold Value (STV). 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 for impairment of REC-1 beneficial uses. 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 (0) of 5 samples exceed the 6-week E.coli Geomean objective and zero (0) of 6 samples exceed the E.coli Statistical Threshold Value (STV) and this this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 26 samples is needed to determine if a beneficial use is fully supported using Table 3.2 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met. 303(d) listing decisions made prior to 2006 were not held in an assessment database. The Regional Boards will update this decision when new data and information become available and are assessed.

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:	303(d) listing decisions made prior to 2006 were not held in an assessment database. The Regional Boards will update this decision when new data and information become available and are assessed.

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 149161, Indicator Bacteria	Region 8
Mountain Home Creek, East Fork

LOE ID:

300993

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

STV

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Water Quality Monitoring Program data for Mountain Home Creek, East Fork to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.

Data Reference:

Field, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 8.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The bacteria water quality objective to protect the REC-1 beneficial use where the salinity is less than 1 parts per thousand 95 percent or more of the time applies a statistical threshold value to E. coli of 320 cfu/100 mL, not to be exceeded by more than 10 percent of samples within a calendar month (ISWEBE 2018).

Objective/Criterion Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): EFMNTCR1 (East Fork Mountain Home Creek 1).

Temporal Representation:

The samples were collected between the days of 2016-12-04 and 2016-12-30 .

Environmental Conditions:

QAPP Information:

SWRCB. 2020. The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence..

QAPP Information Reference(s):

Water Quality Monitoring of 303(D) Listed Streams on the San Bernardino National Forest

Line of Evidence (LOE) for Decision ID 149161, Indicator Bacteria	Region 8
Mountain Home Creek, East Fork

LOE ID:

300975

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

GeoMean

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Water Quality Monitoring Program data for Mountain Home Creek, East Fork to determine beneficial use support and the results are as follows: 0 of the 5 samples exceeded the geomean water quality threshold for E. coli. This is a six week rolling geomean that is calculated weekly.

Data Reference:

Field, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 8.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The bacteria water quality objective to protect the REC-1 beneficial use for waters where the salinity is equal to or less than 1 part per thousand 95 percent or more of the time applies a rolling six-week geometric mean of E. coli, not to exceed 100 cfu/100 mL (ISWEBE 2018).

Objective/Criterion Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): EFMNTCR2 (East Fork Mountain Home Creek 2).

Temporal Representation:

The samples were collected between the days of 2017-01-08 and 2017-05-05 .

Environmental Conditions:

QAPP Information:

SWRCB. 2020. The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence..

QAPP Information Reference(s):

Water Quality Monitoring of 303(D) Listed Streams on the San Bernardino National Forest

Line of Evidence (LOE) for Decision ID 149161, Indicator Bacteria	Region 8
Mountain Home Creek, East Fork

LOE ID:

4425

Pollutant:

Pathogens

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Unspecified--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:

Unspecified

Objective/Criterion Reference:

Placeholder reference pre-2006 303(d)

Evaluation Guideline:

Unspecified

Guideline Reference:

Placeholder reference pre-2006 303(d)

Spatial Representation:

Unspecified

Temporal Representation:

Unspecified

Environmental Conditions:

Unspecified

QAPP Information:

Unspecified

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 149161, Indicator Bacteria	Region 8
Mountain Home Creek, East Fork

LOE ID:

300989

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

STV

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Water Quality Monitoring Program data for Mountain Home Creek, East Fork to determine beneficial use support and the results are as follows: 0 of the 5 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.

Data Reference:

Field, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 8.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): EFMNTCR2 (East Fork Mountain Home Creek 2).

Temporal Representation:

The samples were collected between the days of 2017-01-08 and 2017-05-05 .

Environmental Conditions:

QAPP Information:

SWRCB. 2020. The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence..

QAPP Information Reference(s):

Water Quality Monitoring of 303(D) Listed Streams on the San Bernardino National Forest


DECISION ID	133036	Region 8
Mountain Home Creek, East Fork

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 133036, Alkalinity as CaCO3	Region 8
Mountain Home Creek, East Fork

LOE ID:

234969

Pollutant:

Alkalinity as CaCO3

LOE Subgroup:

Ancillary Line of Evidence

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 Water Quality Monitoring Program data for Mountain Home Creek, East Fork to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Alkalinity as CaCO3.

Data Reference:

Field, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 8.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The concentrations of toxic pollutants in the water column, sediments or biota shall not adversely affect beneficial uses (Water Quality Control Plan for the Santa Ana River Basin).

Objective/Criterion Reference:

Water Quality Control Plan, Santa Ana River Basin

Evaluation Guideline:

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

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: EFMNTCR1 (East Fork Mountain Home Creek 1).

Temporal Representation:

The samples were collected between the dates of 2016-12-08 and 2016-12-30

Environmental Conditions:

QAPP Information:

SWRCB. 2020. The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence..

QAPP Information Reference(s):

The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.

Line of Evidence (LOE) for Decision ID 133036, Alkalinity as CaCO3	Region 8
Mountain Home Creek, East Fork

LOE ID:

235008

Pollutant:

Alkalinity as CaCO3

LOE Subgroup:

Ancillary Line of Evidence

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 Water Quality Monitoring Program data for Mountain Home Creek, East Fork to determine beneficial use support and results are as follows: 0 of 10 samples exceeded the water quality threshold for Alkalinity as CaCO3.

Data Reference:

Field, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 8.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The concentrations of toxic pollutants in the water column, sediments or biota shall not adversely affect beneficial uses (Water Quality Control Plan for the Santa Ana River Basin).

Objective/Criterion Reference:

Water Quality Control Plan, Santa Ana River Basin

Evaluation Guideline:

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

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: EFMNTCR2 (East Fork Mountain Home Creek 2).

Temporal Representation:

The samples were collected between the dates of 2017-01-08 and 2017-05-05

Environmental Conditions:

QAPP Information:

SWRCB. 2020. The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence..

QAPP Information Reference(s):

The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.


DECISION ID	133033	Region 8
Mountain Home Creek, East Fork

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 133033, Oxygen, Dissolved	Region 8
Mountain Home Creek, East Fork

LOE ID:

236923

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Ancillary Line of Evidence

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 Water Quality Monitoring Program data for Mountain Home Creek, East Fork to determine beneficial use support and results are as follows: 0 of 17 samples exceeded the water quality threshold for Oxygen, Dissolved.

Data Reference:

Field, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 8.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The dissolved oxygen content of surface waters shall not be depressed below 6 mg/L for waters designated COLD as a result of controllable water quality factors (Water Quality Control Plan, Santa Ana Basin, Chapter 4 Water Quality Objectives, Inland Surface Waters).

Objective/Criterion Reference:

Water Quality Control Plan, Santa Ana River Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: EFMNTCR2 (East Fork Mountain Home Creek 2).

Temporal Representation:

The samples were collected between the dates of 2017-01-06 and 2017-05-05

Environmental Conditions:

QAPP Information:

SWRCB. 2020. The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence..

QAPP Information Reference(s):

The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.

Line of Evidence (LOE) for Decision ID 133033, Oxygen, Dissolved	Region 8
Mountain Home Creek, East Fork

LOE ID:

237016

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Ancillary Line of Evidence

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 8.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan, Santa Ana River Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: EFMNTCR1 (East Fork Mountain Home Creek 1).

Temporal Representation:

The samples were collected between the dates of 2016-12-29 and 2016-12-30

Environmental Conditions:

QAPP Information:

SWRCB. 2020. The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence..

QAPP Information Reference(s):

The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.


DECISION ID	133035	Region 8
Mountain Home Creek, East Fork

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 133035, Total Dissolved Solids	Region 8
Mountain Home Creek, East Fork

LOE ID:

239870

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Ancillary Line of Evidence

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Groundwater Recharge

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Water Quality Monitoring Program data for Mountain Home Creek, East Fork to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for Total Dissolved Solids.

Data Reference:

Field, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 8.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Site-Specific Objective: The concentration of Total Dissolved Solids shall not exceed 200 mg/L in this waterbody (Water Quality Control Plan for the Santa Ana River Basin).

Objective/Criterion Reference:

Water Quality Control Plan, Santa Ana River Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (EFMNTCR1)

Temporal Representation:

The samples were collected between the dates of 2016-12-30 and 2016-12-30

Environmental Conditions:

QAPP Information:

USFS WQ monitoring

QAPP Information Reference(s):

The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.

Line of Evidence (LOE) for Decision ID 133035, Total Dissolved Solids	Region 8
Mountain Home Creek, East Fork

LOE ID:

239872

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Ancillary Line of Evidence

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 Water Quality Monitoring Program data for Mountain Home Creek, East Fork to determine beneficial use support and results are as follows: 0 of 9 samples exceeded the water quality standard for Total Dissolved Solids.

Data Reference:

Field, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 8.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Site-Specific Objective: The concentration of Total Dissolved Solids shall not exceed 200 mg/L in this waterbody (Water Quality Control Plan for the Santa Ana River Basin).

Objective/Criterion Reference:

Water Quality Control Plan, Santa Ana River Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (EFMNTCR2)

Temporal Representation:

The samples were collected between the dates of 2017-01-08 and 2017-05-05

Environmental Conditions:

QAPP Information:

USFS WQ monitoring

QAPP Information Reference(s):

The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.

Line of Evidence (LOE) for Decision ID 133035, Total Dissolved Solids	Region 8
Mountain Home Creek, East Fork

LOE ID:

239869

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Ancillary Line of Evidence

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Groundwater Recharge

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 8.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Site-Specific Objective: The concentration of Total Dissolved Solids shall not exceed 200 mg/L in this waterbody (Water Quality Control Plan for the Santa Ana River Basin).

Objective/Criterion Reference:

Water Quality Control Plan, Santa Ana River Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (EFMNTCR2)

Temporal Representation:

The samples were collected between the dates of 2017-01-08 and 2017-05-05

Environmental Conditions:

QAPP Information:

USFS WQ monitoring

QAPP Information Reference(s):

The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.

Line of Evidence (LOE) for Decision ID 133035, Total Dissolved Solids	Region 8
Mountain Home Creek, East Fork

LOE ID:

239871

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Ancillary Line of Evidence

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 8.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Site-Specific Objective: The concentration of Total Dissolved Solids shall not exceed 200 mg/L in this waterbody (Water Quality Control Plan for the Santa Ana River Basin).

Objective/Criterion Reference:

Water Quality Control Plan, Santa Ana River Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (EFMNTCR1)

Temporal Representation:

The samples were collected between the dates of 2016-12-30 and 2016-12-30

Environmental Conditions:

QAPP Information:

USFS WQ monitoring

QAPP Information Reference(s):

The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.

Line of Evidence (LOE) for Decision ID 133035, Total Dissolved Solids	Region 8
Mountain Home Creek, East Fork

LOE ID:

239868

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Ancillary Line of Evidence

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 8.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Site-Specific Objective: The concentration of Total Dissolved Solids shall not exceed 200 mg/L in this waterbody (Water Quality Control Plan for the Santa Ana River Basin).

Objective/Criterion Reference:

Water Quality Control Plan, Santa Ana River Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (EFMNTCR2)

Temporal Representation:

The samples were collected between the dates of 2017-01-08 and 2017-05-05

Environmental Conditions:

QAPP Information:

USFS WQ monitoring

QAPP Information Reference(s):

The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.

Line of Evidence (LOE) for Decision ID 133035, Total Dissolved Solids	Region 8
Mountain Home Creek, East Fork

LOE ID:

239867

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Ancillary Line of Evidence

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 8.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Site-Specific Objective: The concentration of Total Dissolved Solids shall not exceed 200 mg/L in this waterbody (Water Quality Control Plan for the Santa Ana River Basin).

Objective/Criterion Reference:

Water Quality Control Plan, Santa Ana River Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (EFMNTCR1)

Temporal Representation:

The samples were collected between the dates of 2016-12-30 and 2016-12-30

Environmental Conditions:

QAPP Information:

USFS WQ monitoring

QAPP Information Reference(s):

The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.


DECISION ID	133034	Region 8
Mountain Home Creek, East Fork

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 133034, pH	Region 8
Mountain Home Creek, East Fork

LOE ID:

237502

Pollutant:

LOE Subgroup:

Ancillary Line of Evidence

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 8.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The pH of inland surface waters shall not be raised above 8.5 or depressed below 6.5 as a result of controllable water quality factors (The Water Quality Control Plan, Santa Ana Basin, Chapter 4 Water Quality Objectives, Inland Surface Waters).

Objective/Criterion Reference:

Water Quality Control Plan, Santa Ana River Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: EFMNTCR1 (East Fork Mountain Home Creek 1).

Temporal Representation:

The samples were collected between the dates of 2016-12-30 and 2016-12-30

Environmental Conditions:

QAPP Information:

SWRCB. 2020. The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence..

QAPP Information Reference(s):

The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.

Line of Evidence (LOE) for Decision ID 133034, pH	Region 8
Mountain Home Creek, East Fork

LOE ID:

237178

Pollutant:

LOE Subgroup:

Ancillary Line of Evidence

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 8.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan, Santa Ana River Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: EFMNTCR2 (East Fork Mountain Home Creek 2).

Temporal Representation:

The samples were collected between the dates of 2017-01-08 and 2017-05-05

Environmental Conditions:

QAPP Information:

SWRCB. 2020. The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence..

QAPP Information Reference(s):

The data included in this LOE does not have a QAPP, but was collected after the QAPP requirements had been developed, and thus was assessed as an ancillary line of evidence.