Draft California 2024 Integrated Report (303(d) List/305(b) Report)

Quality Criteria for Water 1986. United States Environmental Protection Agency. Office of Water. Regulations and Standards. Washington D.C. EPA 440/5-86-001.

Evaluation Guideline:

The USEPA National Recommended Water Quality Criteria (Gold Book) for freshwater aquatic life protection, chronic Lowest Observed Effect Level is 9,400 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2013-11-21 and 2019-01-12

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133777	Region 8
Temescal Creek, Reach 1a

Pollutant:	Acrolein
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 133777, Acrolein	Region 8
Temescal Creek, Reach 1a

LOE ID:

234910

Pollutant:

Acrolein

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Acrolein. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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:

Evaluation Guideline:

The USEPA recommended acrolein criterion for the protection of aquatic life in freshwater is 3 ug/L ( 4-day average).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

Data for this waterbody were collected over the date range 2013-11-21 to 2014-02-28

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133781	Region 8
Temescal Creek, Reach 1a

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133781, Aldrin	Region 8
Temescal Creek, Reach 1a

LOE ID:

234914

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support and results are as follows: 0 of 11 samples exceeded the water quality threshold for Aldrin.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The aldrin criterion maximum concentration (expressed as a 1-day average) to protect aquatic life in freshwater is 1.5 ug/L. The criterion of 3 ug/L provided in the California Toxics Rule is an instantaneous maximum concentration and was divided by 2 in order to better represent a criterion maximum concentration (CMC) value as specified in footnote (g) of Table (b)(1) of the California Toxics Rule (2000).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2013-11-21 and 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133783	Region 8
Temescal Creek, Reach 1a

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 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 133783, Alkalinity as CaCO3	Region 8
Temescal Creek, Reach 1a

LOE ID:

235066

Pollutant:

Alkalinity as CaCO3

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB8 Monitoring data for Temescal Creek, Reach 1a to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3.

Data Reference:

SWAMP Data:

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:

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

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: 801RB8262 (Temescal Wash Random Olsen Site 262).

Temporal Representation:

The samples were collected between the dates of 2012-06-26 and 2012-06-26

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):


DECISION ID	150629	Region 8
Temescal Creek, Reach 1a

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 150629, Ammonia	Region 8
Temescal Creek, Reach 1a

LOE ID:

240224

Pollutant:

Ammonia (Unionized)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support and results are as follows: 0 of 12 samples exceeded the water quality standard for Ammonia as N, Unionized.

Data Reference:

Field, Habitat, Toxicity, 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: To prevent chronic toxicity to aquatic life in the Santa Ana River, Reaches 2, 3, and 4, Chino Creek, Mill Creek (Prado Area), Temescal Creek and San Timoteo Creek, discharges to these waterbodies shall not cause the concentration of un-ionized ammonia (as nitrogen) to exceed 0.098 mg/L (NH3-N) as a 4-day average.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (801TMS746)

Temporal Representation:

The samples were collected between the dates of 2013-11-21 and 2020-03-10

Environmental Conditions:

QAPP Information:

RC NPDES MS4 MP

QAPP Information Reference(s):

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

Line of Evidence (LOE) for Decision ID 150629, Ammonia	Region 8
Temescal Creek, Reach 1a

LOE ID:

240223

Pollutant:

Ammonia (Unionized)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB8 Monitoring data for Temescal Creek, Reach 1a to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality standard for Ammonia as N, Unionized.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (801RB8262)

Temporal Representation:

The samples were collected between the dates of 2012-06-26 and 2012-06-26

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):


DECISION ID	133729	Region 8
Temescal Creek, Reach 1a

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133729, Antimony	Region 8
Temescal Creek, Reach 1a

LOE ID:

235435

Pollutant:

Antimony

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support and results are as follows: 0 of 13 samples exceeded the water quality threshold for Antimony.

Data Reference:

Field, Habitat, Toxicity, 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:

Quality Criteria for Water 1986. United States Environmental Protection Agency. Office of Water. Regulations and Standards. Washington D.C. EPA 440/5-86-001.

Evaluation Guideline:

The USEPA Quality Criteria for Water (Gold Book) states that for antimony toxicity to algae occurs at 610 ug/l. (USEPA, 1986)

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2013-11-21 and 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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

Line of Evidence (LOE) for Decision ID 133729, Antimony	Region 8
Temescal Creek, Reach 1a

LOE ID:

235412

Pollutant:

Antimony

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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:

Quality Criteria for Water 1986. United States Environmental Protection Agency. Office of Water. Regulations and Standards. Washington D.C. EPA 440/5-86-001.

Evaluation Guideline:

The USEPA Quality Criteria for Water (Gold Book) states that for antimony toxicity to algae occurs at 610 ug/l. (USEPA, 1986)

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2013-11-21 and 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133730	Region 8
Temescal Creek, Reach 1a

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133730, Arsenic	Region 8
Temescal Creek, Reach 1a

LOE ID:

235825

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support and results are as follows: 0 of 14 samples exceeded the water quality threshold for Arsenic.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The dissolved arsenic criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 150 ug/L. The conversion factor used to convert the total fraction criterion for arsenic to dissolved fraction criterion is 1. Therefore all data was considered to be representative of the dissolved fraction. (California Toxics Rule, 2000)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2013-11-21 and 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	151784	Region 8
Temescal Creek, Reach 1a

Pollutant:	Atrazine
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 151784, Atrazine	Region 8
Temescal Creek, Reach 1a

LOE ID:

307402

Pollutant:

Atrazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support and the results are as follows: 0 of the 2 samples exceeded the water quality threshold for Atrazine. Although a total of 6 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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:

Evaluation Guideline:

USEPA National Recommended Ambient Water Quality Criteria Aquatic Life Protection Instantaneous Max for atrazine: 1 ug/l.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (801TMS746).

Temporal Representation:

Data for this waterbody was collected over the date range 2013-11-21 to 2018-02-27

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133748	Region 8
Temescal Creek, Reach 1a

Pollutant:	Azinphos-methyl (Guthion)
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 133748, Azinphos-methyl (Guthion)	Region 8
Temescal Creek, Reach 1a

LOE ID:

235547

Pollutant:

Azinphos-methyl (Guthion)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Azinphos Methyl. Although a total of 14 samples were collected, 14 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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:

Evaluation Guideline:

The USEPA National Recommended Water Quality Criteria for azinphos methyl for freshwater aquatic life protection is 0.01 ug/l (instantaneous maximum)

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

Data for this waterbody were collected over the date range 2013-11-21 to 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 8.


DECISION ID	154030	Region 8
Temescal Creek, Reach 1a

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

Regional Board Conclusion:	Benthic Community Effects are being considered for placement on the CWA section 303(d) List under sections 3.9 of the Listing Policy. Under section 3.9, additional lines of evidence (LOEs) associating the Benthic Community Effects decision with a water or sediment concentration of pollutants other than benthic-macroinvertebrate bioassessment or habitat assessment LOEs are necessary to place a water body on the 303(d) List for Benthic Community Effects. One line(s) of evidence evaluating benthic-macroinvertebrate bioassessment data is/are available in the administrative record to assess this indicator. One of one benthic-macroinvertebrate samples exceed the California Stream Condition Index (CSCI) impairment threshold. However, a minimum of two benthic-macroinvertebrate samples are needed to assess listing status. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing Benthic Community Effects in this waterbody segment on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. One of one benthic-macroinvertebrate bioassessment samples had CSCI scores below 0.79. The available information is insufficient to determine whether the waterbody/pollutant combination should be placed on the 303(d) List of impaired waters at this time. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 154030, Benthic Community Effects	Region 8
Temescal Creek, Reach 1a

LOE ID:

314375

Pollutant:

Benthic-Macroinvertebrate Bioassessments

LOE Subgroup:

Population/Community Degradation

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Benthic macroinvertebrate surveys

Data Used to Assess Water Quality:

Water Board staff assessed data for SMC18169 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.45525596 to 0.45525596.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Inland surface water communities and populations, including vertebrate, invertebrate, and plant species, shall not be degraded as a result of the discharge of waste. Degradation is damage to an aquatic community or population with the result that balanced community no longer exists. The concentrations of toxic pollutants in the water column, sediments or biota shall not adversely affect beneficial uses.

Objective/Criterion Reference:

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

Evaluation Guideline:

The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.

Guideline Reference:

Spatial Representation:

Samples were collected from station SMC18169.

Temporal Representation:

Samples were collected from 6/20/2011 to 6/20/2011.

Environmental Conditions:

QAPP Information:

Data collected following SWAMP QA protocols.

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.


DECISION ID	133732	Region 8
Temescal Creek, Reach 1a

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133732, Beryllium	Region 8
Temescal Creek, Reach 1a

LOE ID:

235553

Pollutant:

Beryllium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, 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:

Quality Criteria for Water 1986. United States Environmental Protection Agency. Office of Water. Regulations and Standards. Washington D.C. EPA 440/5-86-001.

Evaluation Guideline:

The Gold Book states that beryllium chronic toxicity to freshwater aquatic life occur at concentrations as low as 5.3 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2013-11-21 and 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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

Line of Evidence (LOE) for Decision ID 133732, Beryllium	Region 8
Temescal Creek, Reach 1a

LOE ID:

235617

Pollutant:

Beryllium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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:

Quality Criteria for Water 1986. United States Environmental Protection Agency. Office of Water. Regulations and Standards. Washington D.C. EPA 440/5-86-001.

Evaluation Guideline:

The Gold Book states that beryllium chronic toxicity to freshwater aquatic life occur at concentrations as low as 5.3 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2013-11-21 and 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133733	Region 8
Temescal Creek, Reach 1a

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133733, Cadmium	Region 8
Temescal Creek, Reach 1a

LOE ID:

239989

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Site-Specific Objective: The Santa Ana River Basin Water Quality Control Plan lists site specific objectives (SSOs) to protect aquatic life in freshwater. The SSOs in freshwater are hardness dependent for each sample and vary based on the ambient hardness during sampling. Sections 4-11 through 4-13 in the Santa Ana River Basin Water Quality Control Plan contain the hardness dependent formula for the metals SSOs.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (801TMS746)

Temporal Representation:

The samples were collected between the dates of 2013-11-21 and 2020-03-10

Environmental Conditions:

QAPP Information:

RC NPDES MS4 MP

QAPP Information Reference(s):

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


DECISION ID	133734	Region 8
Temescal Creek, Reach 1a

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133734, Chlordane	Region 8
Temescal Creek, Reach 1a

LOE ID:

238025

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support and the results are as follows: 0 of the 6 samples exceeded the water quality threshold for Total Chlordane. Although a total of 9 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The chlordane criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0043 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (801TMS746).

Temporal Representation:

Data for this waterbody was collected over the date range 2014-11-01 to 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133735	Region 8
Temescal Creek, Reach 1a

Pollutant:	Chlorpyrifos
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 133735, Chlorpyrifos	Region 8
Temescal Creek, Reach 1a

LOE ID:

235893

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Chlorpyrifos. Although a total of 14 samples were collected, 14 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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 criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Evaluation Guideline:

The freshwater criterion continuous concentration to protect aquatic organisms is 0.015 ug/L (Siepmann and Finlayson 2000, with minor corrections to significant figures as described in Beaulaurier et al., 2005).

Guideline Reference:

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game (with minor corrections to significant figures as described in Beaulaurier et al., 2005).

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

Data for this waterbody were collected over the date range 2013-11-21 to 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133787	Region 8
Temescal Creek, Reach 1a

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133787, Chlorpyrifos, methyl	Region 8
Temescal Creek, Reach 1a

LOE ID:

235913

Pollutant:

Chlorpyrifos, methyl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support and the results are as follows: 0 of the 8 samples exceeded the water quality threshold for Chlorpyrifos Methyl. Although a total of 13 samples were collected, 5 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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:

Evaluation Guideline:

The evaluation guideline for chlorpyrifos methyl is the USEPA Aquatic Life Benchmark of 0.085 ug/L for an invertebrate (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (801TMS746).

Temporal Representation:

Data for this waterbody was collected over the date range 2013-11-21 to 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133789	Region 8
Temescal Creek, Reach 1a

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133789, Chromium	Region 8
Temescal Creek, Reach 1a

LOE ID:

236089

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The dissolved chromium (III) criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is is hardness dependent as described in Table 1 of paragraph (b)(1). The value calculated when using a default hardness of 100 mg/L is 180 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2013-11-21 and 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133736	Region 8
Temescal Creek, Reach 1a

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133736, Chromium, hexavalent	Region 8
Temescal Creek, Reach 1a

LOE ID:

235844

Pollutant:

Chromium, hexavalent

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The dissolved chromium (VI) criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 11 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2013-11-21 and 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133737	Region 8
Temescal Creek, Reach 1a

Pollutant:	Chromium, trivalent
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 133737, Chromium, trivalent	Region 8
Temescal Creek, Reach 1a

LOE ID:

236151

Pollutant:

Chromium, trivalent

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The dissolved chromium (III) criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 180 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2014-11-01 and 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133791	Region 8
Temescal Creek, Reach 1a

Pollutant:	Coumaphos
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 133791, Coumaphos	Region 8
Temescal Creek, Reach 1a

LOE ID:

235870

Pollutant:

Coumaphos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Coumaphos. Although a total of 14 samples were collected, 14 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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:

Evaluation Guideline:

The evaluation guideline for coumaphos is the USEPA Aquatic Life Benchmark of 0.0337 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

Data for this waterbody were collected over the date range 2013-11-21 to 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133739	Region 8
Temescal Creek, Reach 1a

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133739, Cyanide	Region 8
Temescal Creek, Reach 1a

LOE ID:

235873

Pollutant:

Cyanide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The cyanide criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 5.2 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2013-11-21 and 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	149278	Region 8
Temescal Creek, Reach 1a

Pollutant:	DDT (Dichlorodiphenyltrichloroethane)
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 149278, DDT (Dichlorodiphenyltrichloroethane)	Region 8
Temescal Creek, Reach 1a

LOE ID:

236351

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the water quality threshold for DDT(p,p'). Although a total of 5 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The DDT(4,4') criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.001 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (801TMS746).

Temporal Representation:

Data for this waterbody was collected over the date range 2013-11-21 to 2016-11-21

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133790	Region 8
Temescal Creek, Reach 1a

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133790, Demeton	Region 8
Temescal Creek, Reach 1a

LOE ID:

236172

Pollutant:

Demeton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support and the results are as follows: 0 of the 9 samples exceeded the water quality threshold for Demeton, Total. Although a total of 14 samples were collected, 5 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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:

Evaluation Guideline:

The USEPA National Recommended Water Quality criterion for demeton for freshwater aquatic life protection is 0.1 ug/l (4 day average)

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (801TMS746).

Temporal Representation:

Data for this waterbody was collected over the date range 2013-11-21 to 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133741	Region 8
Temescal Creek, Reach 1a

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133741, Diazinon	Region 8
Temescal Creek, Reach 1a

LOE ID:

236208

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support and the results are as follows: 0 of the 8 samples exceeded the water quality threshold for Diazinon. Although a total of 13 samples were collected, 5 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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 for diazinon. Memorandum to J. Karkoski, Central Valley RWQCB. Rancho Cordova, CA: Pesticide Investigation Unit, CA Department of Fish and Game

Evaluation Guideline:

The freshwater chronic value for diazinon is 0.10 ug/L (4 day average)(Finlayson, 2004).

Guideline Reference:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (801TMS746).

Temporal Representation:

Data for this waterbody was collected over the date range 2013-11-21 to 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133742	Region 8
Temescal Creek, Reach 1a

Pollutant:	Dichlorvos
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 133742, Dichlorvos	Region 8
Temescal Creek, Reach 1a

LOE ID:

236243

Pollutant:

Dichlorvos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Dichlorvos. Although a total of 13 samples were collected, 13 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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:

Evaluation Guideline:

The evaluation guideline for dichlorvos is the USEPA Aquatic Life Benchmark of 0.0058 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

Data for this waterbody were collected over the date range 2013-11-21 to 2019-12-04

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133743	Region 8
Temescal Creek, Reach 1a

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133743, Dieldrin	Region 8
Temescal Creek, Reach 1a

LOE ID:

236245

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Dieldrin.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The dieldrin criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.056 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2013-11-21 and 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133778	Region 8
Temescal Creek, Reach 1a

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133778, Dimethoate	Region 8
Temescal Creek, Reach 1a

LOE ID:

236261

Pollutant:

Dimethoate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support and the results are as follows: 0 of the 8 samples exceeded the water quality threshold for Dimethoate. Although a total of 13 samples were collected, 5 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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:

Evaluation Guideline:

The evaluation guideline for dimethoate is the USEPA Aquatic Life Benchmark of 0.5 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (801TMS746).

Temporal Representation:

Data for this waterbody was collected over the date range 2013-11-21 to 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	151785	Region 8
Temescal Creek, Reach 1a

Pollutant:	Disulfoton
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 151785, Disulfoton	Region 8
Temescal Creek, Reach 1a

LOE ID:

307404

Pollutant:

Disulfoton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support and the results are as follows: 0 of the 8 samples exceeded the water quality threshold for Disulfoton. Although a total of 13 samples were collected, 5 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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:

Evaluation Guideline:

USEPA National Recommended Water Quality Criteria Aquatic Life Protection Instantaneous Max for disulfoton: 0.05 ppb.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (801TMS746).

Temporal Representation:

Data for this waterbody was collected over the date range 2013-11-21 to 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133745	Region 8
Temescal Creek, Reach 1a

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133745, Dyfonate (Fonofos or Fonophos)	Region 8
Temescal Creek, Reach 1a

LOE ID:

236246

Pollutant:

Dyfonate (Fonofos or Fonophos)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support and the results are as follows: 0 of the 8 samples exceeded the water quality threshold for Fonofos. Although a total of 13 samples were collected, 5 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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:

OPP Pesticide Ecotoxicity Database.

Evaluation Guideline:

The evaluation guideline for fonofos is the maximum acceptable toxicant concentration (MATC) of 0.45 ug/L. The MATC is calculated as the geometric mean of the lowest observed effect concentration (LOEC) of 0.64 ug/L and the no observed effect concentration (NOEC) of 0.31 ug/L, as determined in a 21 day toxicity study with the water flea, Daphnia magna. Threshold values (LOEC and NOEC) are from USEPA Office of Pesticide Programs Ecotoxicity database.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (801TMS746).

Temporal Representation:

Data for this waterbody was collected over the date range 2013-11-21 to 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133746	Region 8
Temescal Creek, Reach 1a

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133746, Endosulfan sulfate	Region 8
Temescal Creek, Reach 1a

LOE ID:

236298

Pollutant:

Endosulfan sulfate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support and results are as follows: 0 of 9 samples exceeded the water quality threshold for Endosulfan Sulfate.

Data Reference:

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:

Evaluation Guideline:

The USEPA National Recommended Water Quality Criteria toxicity threshold for endosulfan sulfate for freshwater aquatic life protection is 0.056 ug/l (24 hour average)

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2013-11-21 and 2019-01-12

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133747	Region 8
Temescal Creek, Reach 1a

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133747, Endrin	Region 8
Temescal Creek, Reach 1a

LOE ID:

236301

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The endrin criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.036 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2013-11-21 and 2019-01-12

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133775	Region 8
Temescal Creek, Reach 1a

Pollutant:	Ethion
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 133775, Ethion	Region 8
Temescal Creek, Reach 1a

LOE ID:

236391

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 14 samples were collected, 14 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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:

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

Data for this waterbody were collected over the date range 2013-11-21 to 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133779	Region 8
Temescal Creek, Reach 1a

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133779, Ethoprop	Region 8
Temescal Creek, Reach 1a

LOE ID:

236411

Pollutant:

Ethoprop

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support and the results are as follows: 0 of the 8 samples exceeded the water quality threshold for Ethoprop. Although a total of 13 samples were collected, 5 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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:

Evaluation Guideline:

The evaluation guideline for ethoprop is the USEPA Aquatic Life Benchmark of 0.8 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (801TMS746).

Temporal Representation:

Data for this waterbody was collected over the date range 2013-11-21 to 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133776	Region 8
Temescal Creek, Reach 1a

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133776, Ethyl p-nitrophenyl (EPN)	Region 8
Temescal Creek, Reach 1a

LOE ID:

236318

Pollutant:

Ethyl p-nitrophenyl (EPN)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for EPN.

Data Reference:

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:

OPP Pesticide Ecotoxicity Database.

Evaluation Guideline:

The evaluation guideline for EPN is the LC50 of 6.8 ug/L for Gammarus fasciatus (Scud) (USEPA Office of Pesticide Programs Ecotoxicity database).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2013-11-21 and 2014-12-02

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133784	Region 8
Temescal Creek, Reach 1a

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133784, Fenitrothion	Region 8
Temescal Creek, Reach 1a

LOE ID:

236429

Pollutant:

Fenitrothion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support and the results are as follows: 0 of the 8 samples exceeded the water quality threshold for Fenitrothion. Although a total of 13 samples were collected, 5 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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:

Evaluation Guideline:

The evaluation guideline for fenitrothion is the USEPA Aquatic Life Benchmark of 0.087 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (801TMS746).

Temporal Representation:

Data for this waterbody was collected over the date range 2013-11-21 to 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133785	Region 8
Temescal Creek, Reach 1a

Pollutant:	Fenthion
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 133785, Fenthion	Region 8
Temescal Creek, Reach 1a

LOE ID:

236214

Pollutant:

Fenthion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenthion. Although a total of 14 samples were collected, 14 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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:

Evaluation Guideline:

The evaluation guideline for fenthion is the USEPA Aquatic Life Benchmark of 0.013 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

Data for this waterbody were collected over the date range 2013-11-21 to 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133749	Region 8
Temescal Creek, Reach 1a

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133749, Heptachlor	Region 8
Temescal Creek, Reach 1a

LOE ID:

236265

Pollutant:

Heptachlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support and the results are as follows: 0 of the 4 samples exceeded the water quality threshold for Heptachlor. Although a total of 9 samples were collected, 5 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The heptachlor criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0038 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (801TMS746).

Temporal Representation:

Data for this waterbody was collected over the date range 2013-11-21 to 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133750	Region 8
Temescal Creek, Reach 1a

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133750, Heptachlor epoxide	Region 8
Temescal Creek, Reach 1a

LOE ID:

236283

Pollutant:

Heptachlor epoxide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support and the results are as follows: 0 of the 6 samples exceeded the water quality threshold for Heptachlor Epoxide. Although a total of 10 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The heptachlor epoxide criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0038 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (801TMS746).

Temporal Representation:

Data for this waterbody was collected over the date range 2013-11-21 to 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133752	Region 8
Temescal Creek, Reach 1a

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133752, Lead	Region 8
Temescal Creek, Reach 1a

LOE ID:

239991

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support and results are as follows: 1 of 14 samples exceeded the water quality standard for Lead.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (801TMS746)

Temporal Representation:

The samples were collected between the dates of 2013-11-21 and 2020-03-10

Environmental Conditions:

QAPP Information:

RC NPDES MS4 MP

QAPP Information Reference(s):

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


DECISION ID	133753	Region 8
Temescal Creek, Reach 1a

Pollutant:	Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
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 133753, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 8
Temescal Creek, Reach 1a

LOE ID:

236249

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The gamma-BHC (Lindane, gamma-HCH) criterion maximum concentration to protect aquatic life in freshwater is 0.95 ug/L. (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2013-11-21 and 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	149108	Region 8
Temescal Creek, Reach 1a

Pollutant:	Mercury
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 149108, Mercury	Region 8
Temescal Creek, Reach 1a

LOE ID:

236739

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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:

Evaluation Guideline:

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

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2013-11-21 and 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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

Line of Evidence (LOE) for Decision ID 149108, Mercury	Region 8
Temescal Creek, Reach 1a

LOE ID:

236778

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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:

Evaluation Guideline:

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

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2013-11-21 and 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133754	Region 8
Temescal Creek, Reach 1a

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133754, Methyl Parathion	Region 8
Temescal Creek, Reach 1a

LOE ID:

237222

Pollutant:

Methyl Parathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support and the results are as follows: 0 of the 9 samples exceeded the water quality threshold for Parathion, Methyl. Although a total of 14 samples were collected, 5 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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:

Hazard Assessment of the Insecticide Methyl Parathion to Aquatic Organisms in the Sacramento River System

Evaluation Guideline:

The California Department of Fish and Game instantaneous aquatic life criterion for methyl parathion is 0.08 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (801TMS746).

Temporal Representation:

Data for this waterbody was collected over the date range 2013-11-21 to 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133782	Region 8
Temescal Creek, Reach 1a

Pollutant:	Naled
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 133782, Naled	Region 8
Temescal Creek, Reach 1a

LOE ID:

236526

Pollutant:

Naled

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Naled. Although a total of 14 samples were collected, 14 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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:

Evaluation Guideline:

The evaluation guideline for naled is the USEPA Aquatic Life Benchmark of 0.01 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

Data for this waterbody were collected over the date range 2013-11-21 to 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133755	Region 8
Temescal Creek, Reach 1a

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133755, Naphthalene	Region 8
Temescal Creek, Reach 1a

LOE ID:

236529

Pollutant:

Naphthalene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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:

Ambient Water Quality Criteria for Naphthalene

Evaluation Guideline:

The USEPA recommended naphthalene criterion for the protection of freshwater aquatic life is 620 ug/l. (EPA 440/5-80-059)

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2013-11-21 and 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133756	Region 8
Temescal Creek, Reach 1a

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

Regional Board Conclusion:	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 133756, Nickel	Region 8
Temescal Creek, Reach 1a

LOE ID:

236764

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The dissolved nickel criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 52 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2013-11-21 and 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133758	Region 8
Temescal Creek, Reach 1a

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:	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. Two of the 31 samples exceed the WARM dissolved oxygen 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. Two of 31 samples exceeded the WARM dissolved oxygen objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133758, Oxygen, Dissolved	Region 8
Temescal Creek, Reach 1a

LOE ID:

237120

Pollutant:

Oxygen, Dissolved

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 Santa Ana River Regional Monitoring Program data for Temescal Creek, Reach 1a to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Oxygen, Dissolved.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The dissolved oxygen content of surface waters shall not be depressed below 5 mg/L for waters designated WARM 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:

Santa Ana River Watershed Bacteria Monitoring Program

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: P4-RC2 (Temescal Creek at Lincoln Avenue).

Temporal Representation:

The samples were collected between the dates of 2018-06-21 and 2019-06-19

Environmental Conditions:

QAPP Information:

CDM Smith. 2019. Santa Ana River Watershed Bacteria Monitoring Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 133758, Oxygen, Dissolved	Region 8
Temescal Creek, Reach 1a

LOE ID:

237119

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, 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:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2012-12-13 and 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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

Line of Evidence (LOE) for Decision ID 133758, Oxygen, Dissolved	Region 8
Temescal Creek, Reach 1a

LOE ID:

236961

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana River Regional Monitoring Program data for Temescal Creek, Reach 1a to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Oxygen, Dissolved.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Santa Ana River Watershed Bacteria Monitoring Program

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: P4-RC1 (Temescal Creek at Main Street).

Temporal Representation:

The samples were collected between the dates of 2016-06-23 and 2016-10-03

Environmental Conditions:

QAPP Information:

CDM Smith. 2019. Santa Ana River Watershed Bacteria Monitoring Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 133758, Oxygen, Dissolved	Region 8
Temescal Creek, Reach 1a

LOE ID:

236856

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana River Regional Monitoring Program data for Temescal Creek, Reach 1a to determine beneficial use support and results are as follows: 1 of 6 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:

Objective/Criterion Reference:

Santa Ana River Watershed Bacteria Monitoring Program

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: P4-RC2 (Temescal Creek at Lincoln Avenue).

Temporal Representation:

The samples were collected between the dates of 2016-09-09 and 2017-06-22

Environmental Conditions:

QAPP Information:

CDM Smith. 2019. Santa Ana River Watershed Bacteria Monitoring Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 133758, Oxygen, Dissolved	Region 8
Temescal Creek, Reach 1a

LOE ID:

236997

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801RB8262 (Temescal Wash Random Olsen Site 262).

Temporal Representation:

The samples were collected between the dates of 2012-06-26 and 2012-06-26

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):


DECISION ID	133763	Region 8
Temescal Creek, Reach 1a

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133763, PCBs (Polychlorinated biphenyls)	Region 8
Temescal Creek, Reach 1a

LOE ID:

237243

Pollutant:

PCBs (Polychlorinated biphenyls)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support and the results are as follows: 0 of the 6 samples exceeded the water quality threshold for PCBs (Polychlorinated biphenyls). Although a total of 11 samples were collected, 5 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, 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 PCB, total aroclors criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.014 ug/L. This value corresponds to the sum of aroclors 1242, 1254, 1221, 1232, 1248, 1260, and 1016 (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (801TMS746).

Temporal Representation:

Data for this waterbody was collected over the date range 2013-11-21 to 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133760	Region 8
Temescal Creek, Reach 1a

Pollutant:	Parathion
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 133760, Parathion	Region 8
Temescal Creek, Reach 1a

LOE ID:

237220

Pollutant:

Parathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Parathion, Ethyl. Although a total of 14 samples were collected, 14 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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:

Evaluation Guideline:

The USEPA recommended freshwater aquatic life ambient water quality chronic criteria for parathion is 0.013 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

Data for this waterbody were collected over the date range 2013-11-21 to 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133761	Region 8
Temescal Creek, Reach 1a

Pollutant:	Pentachlorophenol (PCP)
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 133761, Pentachlorophenol (PCP)	Region 8
Temescal Creek, Reach 1a

LOE ID:

237268

Pollutant:

Pentachlorophenol (PCP)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The pentachlorophenol criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is pH dependent. The criterion using a default pH value of 7.8 (when pH data is not present) is 15 ug/L. (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2013-11-21 and 2019-11-27

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133780	Region 8
Temescal Creek, Reach 1a

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133780, Phorate	Region 8
Temescal Creek, Reach 1a

LOE ID:

237633

Pollutant:

Phorate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support and the results are as follows: 0 of the 8 samples exceeded the water quality threshold for Phorate. Although a total of 13 samples were collected, 5 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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:

Evaluation Guideline:

The evaluation guideline for phorate is the USEPA Aquatic Life Benchmark of 0.21 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (801TMS746).

Temporal Representation:

Data for this waterbody was collected over the date range 2013-11-21 to 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133786	Region 8
Temescal Creek, Reach 1a

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133786, Phosmet	Region 8
Temescal Creek, Reach 1a

LOE ID:

237637

Pollutant:

Phosmet

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support and the results are as follows: 0 of the 8 samples exceeded the water quality threshold for Phosmet. Although a total of 13 samples were collected, 5 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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:

Evaluation Guideline:

The evaluation guideline for phosmet is the USEPA Aquatic Life Benchmark of 0.75 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (801TMS746).

Temporal Representation:

Data for this waterbody was collected over the date range 2013-11-21 to 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133764	Region 8
Temescal Creek, Reach 1a

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

Regional Board Conclusion:	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 133764, Selenium	Region 8
Temescal Creek, Reach 1a

LOE ID:

237774

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The selenium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 5 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2013-11-21 and 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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

Line of Evidence (LOE) for Decision ID 133764, Selenium	Region 8
Temescal Creek, Reach 1a

LOE ID:

237532

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The selenium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 5 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2013-11-21 and 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133765	Region 8
Temescal Creek, Reach 1a

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

Regional Board Conclusion:	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 133765, Silver	Region 8
Temescal Creek, Reach 1a

LOE ID:

237715

Pollutant:

Silver

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The dissolved silver criterion maximum concentration (CMC) to protect aquatic life in freshwater is hardnesss dependent. The criterion when calculated using a default hardness of 100 mg/L is 3.4 ug/L. This criterion was divided by 2 in order to better represent a CMC value as specified in footnote (g) of Table (b)(1) of the California Toxics Rule, 2000.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2013-11-21 and 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	151786	Region 8
Temescal Creek, Reach 1a

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 151786, Simazine	Region 8
Temescal Creek, Reach 1a

LOE ID:

307407

Pollutant:

Simazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support and results are as follows: 0 of 6 samples exceeded the water quality threshold for Simazine.

Data Reference:

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:

Evaluation Guideline:

USEPA National Recommended Ambient Water Quality Criteria Aquatic Life Protection Instantaneous Max for simazine: 10 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2013-11-21 and 2018-02-27

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133767	Region 8
Temescal Creek, Reach 1a

Pollutant:	Temperature, water
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 3.2 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 conventional or other pollutants (Table 3.2 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 133767, Temperature, water	Region 8
Temescal Creek, Reach 1a

LOE ID:

238020

Pollutant:

Temperature, water

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:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The temperature of waters designated WARM shall not be raised above 90 degrees F June through October or above 78 degrees F during the rest of the year 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:

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801RB8262 (Temescal Wash Random Olsen Site 262).

Temporal Representation:

The samples were collected between the dates of 2012-06-26 and 2012-06-26

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 133767, Temperature, water	Region 8
Temescal Creek, Reach 1a

LOE ID:

237829

Pollutant:

Temperature, water

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 Santa Ana River Regional Monitoring Program data for Temescal Creek, Reach 1a to determine beneficial use support and results are as follows: 0 of 6 samples exceeded the water quality threshold for Temperature.

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:

Santa Ana River Watershed Bacteria Monitoring Program

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: P4-RC1 (Temescal Creek at Main Street).

Temporal Representation:

The samples were collected between the dates of 2016-06-23 and 2016-10-03

Environmental Conditions:

QAPP Information:

CDM Smith. 2019. Santa Ana River Watershed Bacteria Monitoring Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 133767, Temperature, water	Region 8
Temescal Creek, Reach 1a

LOE ID:

237676

Pollutant:

Temperature, water

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:

Data Reference:

Field, Habitat, Toxicity, 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:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2012-12-13 and 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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

Line of Evidence (LOE) for Decision ID 133767, Temperature, water	Region 8
Temescal Creek, Reach 1a

LOE ID:

237860

Pollutant:

Temperature, water

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:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Santa Ana River Watershed Bacteria Monitoring Program

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: P4-RC2 (Temescal Creek at Lincoln Avenue).

Temporal Representation:

The samples were collected between the dates of 2016-09-15 and 2019-06-19

Environmental Conditions:

QAPP Information:

CDM Smith. 2019. Santa Ana River Watershed Bacteria Monitoring Program.

QAPP Information Reference(s):


DECISION ID	133768	Region 8
Temescal Creek, Reach 1a

Pollutant:	Terbufos
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 133768, Terbufos	Region 8
Temescal Creek, Reach 1a

LOE ID:

238076

Pollutant:

Terbufos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Terbufos. Although a total of 14 samples were collected, 14 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, 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:

Evaluation Guideline:

The evaluation guideline for terbufos is the USEPA Aquatic Life Benchmark of 0.03 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

Data for this waterbody were collected over the date range 2013-11-21 to 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133769	Region 8
Temescal Creek, Reach 1a

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133769, Tetrachlorvinphos	Region 8
Temescal Creek, Reach 1a

LOE ID:

238096

Pollutant:

Tetrachlorvinphos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support and the results are as follows: 0 of the 8 samples exceeded the water quality threshold for Tetrachlorvinphos. Although a total of 13 samples were collected, 5 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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:

Evaluation Guideline:

The evaluation guideline for stirophos (tetrachlorvinphos) is the USEPA Aquatic Life Benchmark of 0.125 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (801TMS746).

Temporal Representation:

Data for this waterbody was collected over the date range 2013-11-21 to 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133770	Region 8
Temescal Creek, Reach 1a

Pollutant:	Thallium
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 133770, Thallium	Region 8
Temescal Creek, Reach 1a

LOE ID:

237992

Pollutant:

Thallium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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:

Quality Criteria for Water 1986. United States Environmental Protection Agency. Office of Water. Regulations and Standards. Washington D.C. EPA 440/5-86-001.

Evaluation Guideline:

The USEPA Quality Criteria for Water (Gold Book) states that thallium chronic toxicity to one species of fish occurs at concentrations as low as 20 ug/L after 2,600 hours of exposure. (USEPA, 1986)

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2013-11-21 and 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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

Line of Evidence (LOE) for Decision ID 133770, Thallium	Region 8
Temescal Creek, Reach 1a

LOE ID:

238117

Pollutant:

Thallium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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:

Quality Criteria for Water 1986. United States Environmental Protection Agency. Office of Water. Regulations and Standards. Washington D.C. EPA 440/5-86-001.

Evaluation Guideline:

The USEPA Quality Criteria for Water (Gold Book) states that thallium chronic toxicity to one species of fish occurs at concentrations as low as 20 ug/L after 2,600 hours of exposure. (USEPA, 1986)

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2013-11-21 and 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133771	Region 8
Temescal Creek, Reach 1a

Pollutant:	Toxaphene
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 133771, Toxaphene	Region 8
Temescal Creek, Reach 1a

LOE ID:

238040

Pollutant:

Toxaphene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Toxaphene. Although a total of 11 samples were collected, 11 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The toxaphene criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0002 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

Data for this waterbody were collected over the date range 2013-11-21 to 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133772	Region 8
Temescal Creek, Reach 1a

Pollutant:	Toxicity
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 133772, Toxicity	Region 8
Temescal Creek, Reach 1a

LOE ID:

238170

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

0 of the 1 samples collected by SWAMP RWB8 Monitoring for Temescal Creek, Reach 1a exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Ceriodaphnia dubia for Survival, Ceriodaphnia dubia for Young/female.

Data Reference:

SWAMP Data:

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, Santa Ana Basin, Chapter 4 Water Quality Objectives, Inland Surface Waters).

Objective/Criterion Reference:

Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013

Evaluation Guideline:

The sample is toxic when the response of the organisms exposed to the sample is significantly different (worse) than the response of the organisms exposed to the laboratory control based on statistical hypothesis testing. An exceedance is counted when the significant effect code is “Significant; Less Similarity,” which means that the sample result is significantly different than the control result, and the percent effect is greater than the evaluation threshold. The default evaluation threshold is 20% unless otherwise stated.

Guideline Reference:

Spatial Representation:

The samples were collected at monitoring site: 801RB8262 ( Temescal Wash Random Olsen Site 262 ).

Temporal Representation:

The samples were collected between the dates of 2012-06-26 and 2012-06-26.

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements..

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 133772, Toxicity	Region 8
Temescal Creek, Reach 1a

LOE ID:

238148

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

1 of the 6 samples collected by Santa Ana Region for Temescal Creek, Reach 1a exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Ceriodaphnia dubia for Survival, Selenastrum capricornutum for Total Cell Count, Pimephales promelas for Survival. The following tests exhibited toxicity: Selenastrum capricornutum for Total Cell Count on 2016-11-21.

Data Reference:

Field, Habitat, Toxicity, 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:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at monitoring site: 801TMS746 ( Temescal Channel at Main ).

Temporal Representation:

The samples were collected between the dates of 2016-11-21 and 2019-01-12.

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133773	Region 8
Temescal Creek, Reach 1a

Pollutant:	Trichlorfon
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 133773, Trichlorfon	Region 8
Temescal Creek, Reach 1a

LOE ID:

238059

Pollutant:

Trichlorfon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Trichlorfon. Although a total of 14 samples were collected, 14 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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:

Evaluation Guideline:

The evaluation guideline for trichlorfon is the USEPA Aquatic Life Benchmark of 0.0057 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

Data for this waterbody were collected over the date range 2013-11-21 to 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133774	Region 8
Temescal Creek, Reach 1a

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

Regional Board Conclusion:	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 133774, Zinc	Region 8
Temescal Creek, Reach 1a

LOE ID:

238012

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The dissolved zinc criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 120 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2013-11-21 and 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133740	Region 8
Temescal Creek, Reach 1a

Pollutant:	alpha-Endosulfan (Endosulfan 1)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133740, alpha-Endosulfan (Endosulfan 1)	Region 8
Temescal Creek, Reach 1a

LOE ID:

236281

Pollutant:

alpha-Endosulfan (Endosulfan 1)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support and results are as follows: 1 of 9 samples exceeded the water quality threshold for Endosulfan I.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The endosulfan I (alpha-endosulfan) criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.056 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2013-11-21 and 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133759	Region 8
Temescal Creek, Reach 1a

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133759, beta-Endosulfan (Endosulfan 2)	Region 8
Temescal Creek, Reach 1a

LOE ID:

236296

Pollutant:

beta-Endosulfan (Endosulfan 2)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The endosulfan II (beta-endosulfan) criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.056 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2013-11-21 and 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133738	Region 8
Temescal Creek, Reach 1a

Pollutant:	Copper
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
Expected TMDL Completion Date:	2037
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. One line of evidence are available in the administrative record to assess this pollutant. 10 of the 14 samples exceed the WARM Copper criterion. 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. 10 of the 14 samples exceed the WARM Copper criterion and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133738, Copper	Region 8
Temescal Creek, Reach 1a

LOE ID:

235853

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support and results are as follows: 10 of 14 samples exceeded the water quality threshold for Copper.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The dissolved copper criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 9 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2013-11-21 and 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133751	Region 8
Temescal Creek, Reach 1a

Pollutant:	Iron
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
Expected TMDL Completion Date:	2037
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. Thirteen of the 28 samples exceed the WARM iron objective using the National Recommended Water Quality Criteria. 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. Thirteen of the 28 samples exceed the WARM iron objective using the National Recommended Water Quality Criteria and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133751, Iron	Region 8
Temescal Creek, Reach 1a

LOE ID:

236432

Pollutant:

Iron

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support and results are as follows: 13 of 14 samples exceeded the water quality threshold for Iron.

Data Reference:

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:

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. The evaluation guideline for Iron is 1,000 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2013-11-21 and 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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

Line of Evidence (LOE) for Decision ID 133751, Iron	Region 8
Temescal Creek, Reach 1a

LOE ID:

236304

Pollutant:

Iron

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2013-11-21 and 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133757	Region 8
Temescal Creek, Reach 1a

Pollutant:	Oil and Grease
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
Expected TMDL Completion Date:	2037
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. One line of evidence are available in the administrative record to assess this pollutant. Four of the four samples exceed the WARM Oil guideline. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Four of the four samples exceed the WARM Oil guideline, and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133757, Oil and Grease	Region 8
Temescal Creek, Reach 1a

LOE ID:

236829

Pollutant:

Oil and Grease

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support and the results are as follows: 4 of the 4 samples exceeded the water quality threshold for OilandGrease; HEM. Although a total of 8 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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:

Quality Criteria for Water 1986. United States Environmental Protection Agency. Office of Water. Regulations and Standards. Washington D.C. EPA 440/5-86-001.

Evaluation Guideline:

According to the USEPA Quality Criteria for Water (Gold Book), concentrations of oil at 0.001 mg/L can harm aquatic life. (USEPA, 1986)

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (801TMS746).

Temporal Representation:

Data for this waterbody was collected over the date range 2014-12-02 to 2019-12-04

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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


DECISION ID	133762	Region 8
Temescal Creek, Reach 1a

Pollutant:	pH
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
Expected TMDL Completion Date:	2037
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. Four lines of evidence are available in the administrative record to assess this pollutant. 11 of the 26 samples exceed the WARM pH 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. 11 of the 26 samples exceed the WARM pH objective and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 133762, pH	Region 8
Temescal Creek, Reach 1a

LOE ID:

237314

Pollutant:

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 Santa Ana River Regional Monitoring Program data for Temescal Creek, Reach 1a to determine beneficial use support and results are as follows: 3 of 6 samples exceeded the water quality threshold for pH.

Data Reference:

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:

Santa Ana River Watershed Bacteria Monitoring Program

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: P4-RC1 (Temescal Creek at Main Street).

Temporal Representation:

The samples were collected between the dates of 2016-06-23 and 2016-10-03

Environmental Conditions:

QAPP Information:

CDM Smith. 2019. Santa Ana River Watershed Bacteria Monitoring Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 133762, pH	Region 8
Temescal Creek, Reach 1a

LOE ID:

237309

Pollutant:

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 Santa Ana River Regional Monitoring Program data for Temescal Creek, Reach 1a to determine beneficial use support and results are as follows: 5 of 6 samples exceeded the water quality threshold for pH.

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:

Santa Ana River Watershed Bacteria Monitoring Program

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: P4-RC2 (Temescal Creek at Lincoln Avenue).

Temporal Representation:

The samples were collected between the dates of 2016-09-15 and 2019-06-19

Environmental Conditions:

QAPP Information:

CDM Smith. 2019. Santa Ana River Watershed Bacteria Monitoring Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 133762, pH	Region 8
Temescal Creek, Reach 1a

LOE ID:

237259

Pollutant:

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 Santa Ana Region data for Temescal Creek, Reach 1a to determine beneficial use support and results are as follows: 2 of 13 samples exceeded the water quality threshold for pH.

Data Reference:

Field, Habitat, Toxicity, 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:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 801TMS746 (Temescal Channel at Main).

Temporal Representation:

The samples were collected between the dates of 2012-12-13 and 2020-03-10

Environmental Conditions:

QAPP Information:

Riverside County Watershed Protection. 2021. VOLUME II: QUALITY ASSURANCE PROJECT PLAN.

QAPP Information Reference(s):

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

Line of Evidence (LOE) for Decision ID 133762, pH	Region 8
Temescal Creek, Reach 1a

LOE ID:

237255

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference: