Final 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: 745836 (R-003D).

Temporal Representation:

The samples were collected between the dates of 2011-11-01 and 2020-02-18

Environmental Conditions:

QAPP Information:

IEUA. 2019. Laboratory Quality Assurance Manual.

QAPP Information Reference(s):

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 8.


DECISION ID	133194	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 133194, Acrolein	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239662

Pollutant:

Acrolein

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:

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: 745836 (R-003D).

Temporal Representation:

The samples were collected between the dates of 2011-11-01 and 2020-02-18

Environmental Conditions:

QAPP Information:

IEUA. 2019. Laboratory Quality Assurance Manual.

QAPP Information Reference(s):

Concentrations of Pesticides in the waterbodies in the Santa Ana Region


DECISION ID	132387	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

Pollutant:	Alachlor
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 132387, Alachlor	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

234665

Pollutant:

Alachlor

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:

Of the 2 samples collected, none exceeded the guidelines.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The concentration of toxic substance in the water column, sediments or biota shall not adversely affect beneficial uses (SARWQCB, 1995).

Objective/Criterion Reference:

Water Quality Control Plan for the Santa Ana River Basin

Evaluation Guideline:

USEPA National Recommended Ambient Water Quality Criteria Aquatic Life Protection Instantaneous Max for alachlor: 76 ug/l.

Guideline Reference:

Spatial Representation:

The samples were collected from two locations: Chino C Above Central Ave Near Los Serranos California_USGS NAWQA site and Little Chino C Above Pipeline Ave Near Los Serranos California_USGS NAWQA site

Temporal Representation:

The samples were collected on 8/7/00 and 8/11/00.

Environmental Conditions:

QAPP Information:

The data's quality is deemed appropriate because the data came from the Department of Pesticide Regulations.

QAPP Information Reference(s):

This is a placeholder for previously assessed data that does not have quality assurance information but would require it under newly developed policies. These LOEs were previously assessed and approved at the Regional, State and Federal level in past cycles. The LOEs needed to be moved and/or reassessed but required this reference code for movement within the decision making database.


DECISION ID	133195	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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

Line of Evidence (LOE) for Decision ID 133195, Aldrin	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239664

Pollutant:

Aldrin

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 eSMR_IEUA Regional Plant No. 5 data for Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel) to determine beneficial use support and the results are as follows: 0 of the 8 samples exceeded the water quality threshold for Aldrin. Although a total of 9 samples were collected, 1 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:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 8.

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 (745836).

Temporal Representation:

Data for this waterbody was collected over the date range 2011-11-01 to 2020-02-18

Environmental Conditions:

QAPP Information:

IEUA. 2019. Laboratory Quality Assurance Manual.

QAPP Information Reference(s):

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 8.


DECISION ID	132388	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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

Regional Board Conclusion:	During 2024 cycle, the 1988 National Recommended Water Quality Criteria used to assess aluminum data was replaced with U.S. EPA’s 2018 Final Recommended Aquatic Life Criteria for Aluminum in Freshwater. Some previous cycle aluminum data could not be located, and as a result those data were not reassessed against the new Criteria and were not included in this decision. This pollutant is being considered for placement on the CWA section 303(d) List under sections 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. Two of 13 samples exceed the evaluation guideline for the aquatic life beneficial use. However, the fraction (total or dissolved) was not recorded for the samples in LOE 307218 and so this data cannot be used to make a listing recommendation. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Two of 13 samples exceed the evaluation guideline for the aquatic life beneficial use, and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. As pH data were not available, and the median pH value for the ecoregion was used as a comparable surrogate, section 3.11 will be used as the basis for listing. However, the fraction (total or dissolved) was not recorded, and these samples cannot be used to make a listing recommendation.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 132388, Aluminum	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

307219

Pollutant:

Aluminum

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:

Final Aquatic Life Ambient Water Quality Criteria for Aluminum. EPA-822-R-18-001. Washington, D.C.: Office of Water, USEPA.

Evaluation Guideline:

The aluminum criterion for the protection of aquatic life, is pH, total hardness, and dissolved organic carbon (DOC) dependent. When total hardness or DOC data were not available, default values based on the level III ecoregions developed by U.S EPA were substituted (EPA, 2018). When pH data were not available, the median pH value for the ecoregion, a pH value from a comparable waterbody, or a pH value from a local study in the same waterbody was used as a comparable surrogate.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 745836 (R-003D).

Temporal Representation:

The samples were collected between the dates of 2011-06-08 and 2020-02-18

Environmental Conditions:

QAPP Information:

IEUA. 2019. Laboratory Quality Assurance Manual.

QAPP Information Reference(s):

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 8.

Line of Evidence (LOE) for Decision ID 132388, Aluminum	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

307218

Pollutant:

Aluminum

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:

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:

Final Aquatic Life Ambient Water Quality Criteria for Aluminum. EPA-822-R-18-001. Washington, D.C.: Office of Water, USEPA.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 745836 (R-003D).

Temporal Representation:

The samples were collected between the dates of 2011-06-08 and 2020-02-18

Environmental Conditions:

QAPP Information:

IEUA. 2019. Laboratory Quality Assurance Manual.

QAPP Information Reference(s):

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 8.


DECISION ID	150570	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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 150570, Ammonia	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239728

Pollutant:

Ammonia (Unionized)

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:

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 (745836)

Temporal Representation:

The samples were collected between the dates of 2019-01-30 and 2019-01-30

Environmental Conditions:

QAPP Information:

IEUA QA documents

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	133153	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 133153, Anthracene	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

238656

Pollutant:

Anthracene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

SWAMP

Water Quality Objective/Criterion:

Toxic substances shall not be discharged at levels that will bioaccumulate in aquatic resources to level which are harmful to human health. The concentrations of toxic substances in the water column, sediments or biota shall not adversely affect beneficial uses.

Objective/Criterion Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Evaluation Guideline:

The evaluation guideline for anthracene is the probable effect concentration (PEC) of 845 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2019-05-30

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.


DECISION ID	133154	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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

Line of Evidence (LOE) for Decision ID 133154, Antimony	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239668

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:

WQ data from the California Integrated Water Quality System (CIWQS) 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: 745836 (R-003D).

Temporal Representation:

The samples were collected between the dates of 2011-06-08 and 2020-02-18

Environmental Conditions:

QAPP Information:

IEUA. 2019. Laboratory Quality Assurance Manual.

QAPP Information Reference(s):

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 8.

Line of Evidence (LOE) for Decision ID 133154, Antimony	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239670

Pollutant:

Antimony

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:

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: 745836 (R-003D).

Temporal Representation:

The samples were collected between the dates of 2011-06-08 and 2020-02-18

Environmental Conditions:

QAPP Information:

IEUA. 2019. Laboratory Quality Assurance Manual.

QAPP Information Reference(s):

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 8.


DECISION ID	133155	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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

Line of Evidence (LOE) for Decision ID 133155, Arsenic	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239675

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:

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: 745836 (R-003D).

Temporal Representation:

The samples were collected between the dates of 2011-06-08 and 2020-02-18

Environmental Conditions:

QAPP Information:

IEUA. 2019. Laboratory Quality Assurance Manual.

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 133155, Arsenic	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

238692

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Evaluation Guideline:

The evaluation guideline for arsenic is the probable effect concentration (PEC) of 33 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2018-05-21

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.


DECISION ID	132369	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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 132369, Atrazine	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

234666

Pollutant:

Atrazine

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:

Of the 2 samples collected, none exceeded the guidelines.

Data Reference:

Concentrations of Pesticides in the waterbodies in the Santa Ana Region

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The concentration of toxic substance in the water column, sediments or biota shall not adversely affect beneficial uses (SARWQCB, 1995).

Objective/Criterion Reference:

Water Quality Control Plan for the Santa Ana River Basin

Evaluation Guideline:

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

Guideline Reference:

Spatial Representation:

Temporal Representation:

The samples were collected on 8/7/00 and 8/11/00.

Environmental Conditions:

QAPP Information:

The data's quality is deemed appropriate because the data came from the Department of Pesticide Regulations.

QAPP Information Reference(s):


DECISION ID	132376	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 132376, Azinphos-methyl (Guthion)	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

234667

Pollutant:

Azinphos-methyl (Guthion)

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:

Of the 2 samples collected, none exceeded the guidelines.

Data Reference:

Concentrations of Pesticides in the waterbodies in the Santa Ana Region

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The concentration of toxic substance in the water column, sediments or biota shall not adversely affect beneficial uses (SARWQCB, 1995).

Objective/Criterion Reference:

Water Quality Control Plan for the Santa Ana River Basin

Evaluation Guideline:

USEPA National Recommended Ambient Water Quality Criteria Aquatic Life Protection Instantaneous Max for azinphos methyl: 0.01 ug/l.

Guideline Reference:

Spatial Representation:

Temporal Representation:

The samples were collected on 8/7/00 and 8/11/00.

Environmental Conditions:

QAPP Information:

The data's quality is deemed appropriate because the data came from the Department of Pesticide Regulations.

QAPP Information Reference(s):


DECISION ID	133157	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 133157, Benzo(a)anthracene	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

238756

Pollutant:

Benzo(a)anthracene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Evaluation Guideline:

The evaluation guideline for benz[a]anthrazene is the probable effect concentration (PEC) of 1050 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2019-05-30

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.


DECISION ID	133156	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 133156, Benzo(a)pyrene	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

238721

Pollutant:

Benzo(a)pyrene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Evaluation Guideline:

The evaluation guideline for benzo[a]pyrene is the probable effect concentration (PEC) of 1450 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2019-05-30

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.


DECISION ID	133158	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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

Line of Evidence (LOE) for Decision ID 133158, Beryllium	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239678

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:

WQ data from the California Integrated Water Quality System (CIWQS) 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: 745836 (R-003D).

Temporal Representation:

The samples were collected between the dates of 2011-06-08 and 2020-02-18

Environmental Conditions:

QAPP Information:

IEUA. 2019. Laboratory Quality Assurance Manual.

QAPP Information Reference(s):

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 8.

Line of Evidence (LOE) for Decision ID 133158, Beryllium	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239676

Pollutant:

Beryllium

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:

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: 745836 (R-003D).

Temporal Representation:

The samples were collected between the dates of 2011-06-08 and 2020-02-18

Environmental Conditions:

QAPP Information:

IEUA. 2019. Laboratory Quality Assurance Manual.

QAPP Information Reference(s):

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 8.


DECISION ID	132370	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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

Line of Evidence (LOE) for Decision ID 132370, Cadmium	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239729

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 (745836)

Temporal Representation:

The samples were collected between the dates of 2011-06-08 and 2020-02-18

Environmental Conditions:

QAPP Information:

IEUA QA documents

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 132370, Cadmium	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

238841

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Evaluation Guideline:

The evaluation guideline for cadmium is the probable effect concentration (PEC) of 4.98 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2018-05-21

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 132370, Cadmium	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

234805

Pollutant:

Cadmium

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:

The sample did not exceeded the standard.

Data Reference:

Water Quality Control Plan for the Santa Ana River Basin

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The concentration of toxic substance in the water column, sediments or biota shall not adversely affect beneficial uses (SARWQCB, 1995).

Objective/Criterion Reference:

Evaluation Guideline:

The California Toxics Rule criteria for cadmium (hardness dependent): 5.09 ppb.

Guideline Reference:

Spatial Representation:

The sample was taken in Chino Creek at Pine Avenue.

Temporal Representation:

The sample was taken on 8/16/2005.

Environmental Conditions:

QAPP Information:

The data's quality is deemed acceptable because it was submitted by an NPDES discharger in accordance with its Monitoring and Reporting Requirements.

QAPP Information Reference(s):


DECISION ID	132371	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 132371, Carbaryl	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

234668

Pollutant:

Carbaryl

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:

Of the 2 samples collected, none exceeded the guidelines.

Data Reference:

Concentrations of Pesticides in the waterbodies in the Santa Ana Region

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The concentration of toxic substance in the water column, sediments or biota shall not adversely affect beneficial uses (SARWQCB, 1995).

Objective/Criterion Reference:

Water Quality Control Plan for the Santa Ana River Basin

Evaluation Guideline:

USEPA National Recommended Ambient Water Quality Criteria Aquatic Life Protection Instantaneous Max for carbaryl: 0.02 ug/l.

Guideline Reference:

Spatial Representation:

Temporal Representation:

The samples were collected on 8/7/00 and 8/11/00.

Environmental Conditions:

QAPP Information:

The data's quality is deemed appropriate because the data came from the Department of Pesticide Regulations.

QAPP Information Reference(s):


DECISION ID	132372	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

Pollutant:	Carbofuran
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 132372, Carbofuran	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

234683

Pollutant:

Carbofuran

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:

Of the 2 samples collected, none exceeded the guidelines.

Data Reference:

Concentrations of Pesticides in the waterbodies in the Santa Ana Region

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The concentration of toxic substance in the water column, sediments or biota shall not adversely affect beneficial uses (SARWQCB, 1995).

Objective/Criterion Reference:

Water Quality Control Plan for the Santa Ana River Basin

Evaluation Guideline:

USEPA National Recommended Ambient Water Quality Criteria Aquatic Life Protection Instantaneous Max for carbofuran: 0.5 ug/l.

Guideline Reference:

Spatial Representation:

Temporal Representation:

The samples were collected on 8/7/00 and 8/11/00.

Environmental Conditions:

QAPP Information:

The data's quality is deemed appropriate because the data came from the Department of Pesticide Regulations.

QAPP Information Reference(s):


DECISION ID	133159	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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:	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 133159, Chlordane	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

238798

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Evaluation Guideline:

The evaluation guideline for chlordane is the probable effect concentration (PEC) of 17.6 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2017-05-16

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.


DECISION ID	133160	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

Pollutant:	Chloride
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Two lines of evidence are available in the administrative record to assess this pollutant. 157 of the 188 samples exceed the Chloride objective. This assessment utilized a 7-day averaging period instead of an annual flow-weighted average. Please see the staff report for more information. The Water Board has not yet undertaken the evaluation of information in the Integrated Report record to determine that the exceedances are the result of controllable water quality factors, which means there is insufficient information to conclude the objectives are exceeded as a result of controllable water quality factors. However, the number of exceedances out of the number of samples, using the Listing Policy binomial distribution, indicate beneficial uses may be potentially threatened. Therefore, as an interim approach until waterbody-specific information on controllable water quality factors is evaluated or added to the record, the weight of evidence indicates that there is sufficient justification against placing this waterbody-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. 157 of the 188 samples exceed the Chloride 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. 5. Pursuant to page 4-10 of the Santa Ana Water Board Basin Plan: The dissolved mineral content of the waters of the region, as measured by the total dissolved solids test (“Standard Methods for the Examination of Water and Wastewater, 16th Ed.,” 1985: 209B (180°C), p. 95), shall not exceed the specific objectives listed in Table 4-1 as a result of controllable water quality factors. Previous decision language below: One (1) line of evidence is available in the administrative record to assess this pollutant. One hundred fifty-six (156) of the one hundred eighty-four (184) samples exceed this site specific antidegradation objective, found in Table 4-1 of the Region 8 Basin Plan. While this number of exceedances would normally provide sufficient justification in favor of placing this water segment-pollutant combination on the CWA section 303(d) List, none of the exceedances would cause an impairment of any of the beneficial uses assigned to this waterbody (REC1, REC2, WARM, WILD, RARE). Table 4-1 of the Region 8 Basin Plan identifies site specific water quality objectives based on historical values of Total Dissolved Solids, Hardness, Sodium, Chloride, Total Inorganic Nitrogen, Sulfate and Chemical Oxygen Demand, that were intended to be protective of the groundwater aquifers underlying those surface waterbodies identified in Table 4-1. Regional Board staff have recognized that the Groundwater Recharge beneficial use is more correctly assessed using actual groundwater data rather than by monitoring surface waters. Region Board Resolution No. R8-2004-0001 deleted the groundwater objectives for individual minerals from the Basin Plan, but not the individual mineral objectives for all surface waters. Therefore, as no designated beneficial uses of this waterbody segment are being impaired by these exceedances, the weight of evidence supports a decision to not list this waterbody 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 and instead placed in Category 3 because waterbody-specific information on controllable water quality factors has not been evaluated or added to the record.

State Board Review of Regional Board Conclusion and Recommendation:	Previous decision language below: One (1) line of evidence is available in the administrative record to assess this pollutant. One hundred fifty-six (156) of the one hundred eighty-four (184) samples exceed this site specific antidegradation objective, found in Table 4-1 of the Region 8 Basin Plan. While this number of exceedances would normally provide sufficient justification in favor of placing this water segment-pollutant combination on the CWA section 303(d) List, none of the exceedances would cause an impairment of any of the beneficial uses assigned to this waterbody (REC1, REC2, WARM, WILD, RARE). Table 4-1 of the Region 8 Basin Plan identifies site specific water quality objectives based on historical values of Total Dissolved Solids, Hardness, Sodium, Chloride, Total Inorganic Nitrogen, Sulfate and Chemical Oxygen Demand, that were intended to be protective of the groundwater aquifers underlying those surface waterbodies identified in Table 4-1. Regional Board staff have recognized that the Groundwater Recharge beneficial use is more correctly assessed using actual groundwater data rather than by monitoring surface waters. Region Board Resolution No. R8-2004-0001 deleted the groundwater objectives for individual minerals from the Basin Plan, but not the individual mineral objectives for all surface waters. Therefore, as no designated beneficial uses of this waterbody segment are being impaired by these exceedances, the weight of evidence supports a decision to not list this waterbody segment ¿ pollutant combination on the CWA section 303(d) List.

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 and instead placed in Category 3 because waterbody-specific information on controllable water quality factors has not been evaluated or added to the record.

Line of Evidence (LOE) for Decision ID 133160, Chloride	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

81362

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

184

Number of Exceedances:

156

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Numeric data generated from 184 samples collected had 156 exceedences of the site-specific objective.

Data Reference:

Data for Metals and Other Inorganic Pollutants in Orange County Water District, 1994-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The site-pecific objective for Chloride at Chino Creek Reach 1B according to table 4-1 of the Santa Ana Basin plan is 75 mg/L.

Objective/Criterion Reference:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 8.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data was collected from the CK-CHINO-03 station.

Temporal Representation:

Data was collected approximately once a month from February 1994 to August 2009.

Environmental Conditions:

QAPP Information:

The samples were collected under the Orange County Water District Main Laboratory Quality Assurance Manual. November 2009.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 133160, Chloride	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239730

Pollutant:

Chloride

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:

Site-Specific Objective: The concentration of Chloride shall not exceed 75 mg/L in this waterbody (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 (745836)

Temporal Representation:

The samples were collected between the dates of 2011-06-08 and 2011-09-07

Environmental Conditions:

QAPP Information:

IEUA QA documents

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	133161	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 133161, Chlorpyrifos	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

238900

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Evaluation Guideline:

The evaluation guideline for chlorpyrifos is the median lethal concentration (LC50) of 1.77 ug/g and is normalized by the percentage of organic carbon in the sediment sample (Amweg and Weston, 2007).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2017-05-16

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.


DECISION ID	133200	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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

Line of Evidence (LOE) for Decision ID 133200, Chromium	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239686

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:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 8.

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: 745836 (R-003D).

Temporal Representation:

The samples were collected between the dates of 2011-06-08 and 2020-02-18

Environmental Conditions:

QAPP Information:

IEUA. 2019. Laboratory Quality Assurance Manual.

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 133200, Chromium	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

238921

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Evaluation Guideline:

The evaluation guideline for chromium is the probable effect concentration (PEC) of 111 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2018-05-21

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.


DECISION ID	132373	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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

Line of Evidence (LOE) for Decision ID 132373, Chromium, hexavalent	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

234791

Pollutant:

Chromium, hexavalent

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:

The only sample collected did not exceed the guideline.

Data Reference:

Water Quality Control Plan for the Santa Ana River Basin

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The concentration of toxic substance in the water column, sediments or biota shall not adversely affect beneficial uses (SARWQCB, 1995).

Objective/Criterion Reference:

Evaluation Guideline:

California Toxics Rule Fresh Water Aquatic Life Protection 4-day average continuous concentration for chromium, hexavalent: 11 ppb.

Guideline Reference:

Compilation of Water Quality Goals

Spatial Representation:

The sample was collected in Chino Creek at Pine Avenue.

Temporal Representation:

The sample was collected on August 16, 2005.

Environmental Conditions:

QAPP Information:

The data's quality is deemed acceptable because it was submitted by an NPDES discharger in accordance with its Monitoring and Reporting Requirements.

QAPP Information Reference(s):


DECISION ID	133162	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

Pollutant:	Chrysene (C1-C4)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 133162, Chrysene (C1-C4)	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

238885

Pollutant:

Chrysene (C1-C4)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Evaluation Guideline:

The evaluation guideline for chrysene is the probable effect concentration (PEC) of 1290 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2019-05-30

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.


DECISION ID	132374	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 132374, Copper	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

234806

Pollutant:

Copper

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:

The sample did not exceeded the standard.

Data Reference:

Water Quality Control Plan for the Santa Ana River Basin

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The concentration of toxic substance in the water column, sediments or biota shall not adversely affect beneficial uses (SARWQCB, 1995).

Objective/Criterion Reference:

Evaluation Guideline:

The California Toxics Rule criteria for copper (hardness dependent): 20.55 ppb.

Guideline Reference:

Spatial Representation:

The sample was taken in Chino Creek at Pine Avenue.

Temporal Representation:

The sample was taken on 8/16/2005.

Environmental Conditions:

QAPP Information:

The data's quality is deemed acceptable because it was submitted by an NPDES discharger in accordance with its Monitoring and Reporting Requirements.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 132374, Copper	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

238934

Pollutant:

Copper

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Evaluation Guideline:

The evaluation guideline for copper is the probable effect concentration (PEC) of 149 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2018-05-21

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.


DECISION ID	133197	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

Pollutant:	Cyfluthrin
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 133197, Cyfluthrin	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239043

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Evaluation Guideline:

The evaluation guideline for cyfluthrin is the median lethal concentration (LC50) of 1.1 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.1 ug/g is the geometric mean of LC50 values for cyfluthrin (Amweg et al., 2005).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2019-05-30

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.


DECISION ID	133199	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

Pollutant:	Cyhalothrin, Lambda
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 133199, Cyhalothrin, Lambda	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239049

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Evaluation Guideline:

The evaluation guideline for lambda-cyhalothrin is the median lethal concentration (LC50) of 0.44 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.44 ug/g is the geometric mean of LC50 values for lambda-cyhalothrin (Amweg et al., 2005).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2019-05-30

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.


DECISION ID	133193	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

Pollutant:	Cypermethrin
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 133193, Cypermethrin	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239054

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Evaluation Guideline:

The evaluation guideline for cypermethrin is the median lethal concentration (LC50) of 0.3 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.3 ug/g is the geometric mean of LC50 values for cypermethrin from Maund et al., (2002).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2019-05-30

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.


DECISION ID	149245	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

Pollutant:	DDD (Dichlorodiphenyldichloroethane)
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 149245, DDD (Dichlorodiphenyldichloroethane)	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239063

Pollutant:

DDD (Dichlorodiphenyldichloroethane)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Evaluation Guideline:

The evaluation guideline for the sum of DDD is the probable effect concentration (PEC) of 28 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2015-05-05

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.


DECISION ID	149244	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

Pollutant:	DDE (Dichlorodiphenyldichloroethylene)
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 149244, DDE (Dichlorodiphenyldichloroethylene)	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

234684

Pollutant:

DDE (Dichlorodiphenyldichloroethylene)

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:

Of the 2 samples collected, none exceeded the guidelines.

Data Reference:

Concentrations of Pesticides in the waterbodies in the Santa Ana Region

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The concentration of toxic substance in the water column, sediments or biota shall not adversely affect beneficial uses (SARWQCB, 1995).

Objective/Criterion Reference:

Water Quality Control Plan for the Santa Ana River Basin

Evaluation Guideline:

USEPA National Recommended Ambient Water Quality Criteria Aquatic Life Protection continuous concentration 4-day average for DDE: 0.001 ug/l.

Guideline Reference:

Spatial Representation:

Temporal Representation:

The samples were collected on 8/7/00 and 8/11/00.

Environmental Conditions:

QAPP Information:

The data's quality is deemed appropriate because the data came from the Department of Pesticide Regulations.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 149244, DDE (Dichlorodiphenyldichloroethylene)	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239075

Pollutant:

DDE (Dichlorodiphenyldichloroethylene)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Evaluation Guideline:

The evaluation guideline for the sum of DDE is the probable effect concentration (PEC) of 31.3 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2017-05-16

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.


DECISION ID	149246	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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 149246, DDT (Dichlorodiphenyltrichloroethane)	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239693

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

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 eSMR_IEUA Regional Plant No. 5 data for Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDT(p,p'). Although a total of 9 samples were collected, 9 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:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 8.

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: 745836 (R-003D).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-11-01 to 2020-02-18

Environmental Conditions:

QAPP Information:

IEUA. 2019. Laboratory Quality Assurance Manual.

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 149246, DDT (Dichlorodiphenyltrichloroethane)	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239530

Pollutant:

Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Evaluation Guideline:

The evaluation guideline for total DDTs is the probable effect concentration (PEC) of 572 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2017-05-16

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 149246, DDT (Dichlorodiphenyltrichloroethane)	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239080

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Evaluation Guideline:

The evaluation guideline for the sum of DDT is the probable effect concentration (PEC) of 62.9 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2015-05-05

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.


DECISION ID	133198	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

Pollutant:	Deltamethrin
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 133198, Deltamethrin	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239017

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Evaluation Guideline:

The evaluation guideline for deltamethrin is the median lethal concentration (LC50) of 0.79 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.79 ug/g is the geometric mean of LC50 values for deltamethrin (Amweg et al., 2005).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2017-05-16

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.


DECISION ID	133164	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

Pollutant:	Diazinon
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 133164, Diazinon	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239025

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Evaluation Guideline:

The evaluation guideline for diazinon is the median lethal concentration (LC50) of 11 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 11 ug/g is the geometric mean of LC50 values for diazinon from Ding et al., (2011).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2015-05-05

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 133164, Diazinon	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

7798

Pollutant:

Diazinon

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:

Of the two samples collected, one exceeded the guideline.

Data Reference:

Concentrations of Pesticides in the waterbodies in the Santa Ana Region

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Santa Ana Region¿s Basin Plan Narrative Objective: The concentrations of toxic pollutants in the water column, sediments or biota shall not adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Santa Ana River Basin

Evaluation Guideline:

California Department of Fish and Game 0.08 ppb

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

Spatial Representation:

Temporal Representation:

The samples were collected on 8/7/00 and 8/11/00

Environmental Conditions:

QAPP Information:

The data's quality is deemed appropriate because it came from the Department of Pesticide Regulation.

QAPP Information Reference(s):


DECISION ID	133165	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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

Line of Evidence (LOE) for Decision ID 133165, Dieldrin	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239697

Pollutant:

Dieldrin

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 eSMR_IEUA Regional Plant No. 5 data for Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel) to determine beneficial use support and the results are as follows: 0 of the 8 samples exceeded the water quality threshold for Dieldrin. Although a total of 9 samples were collected, 1 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:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 8.

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 (745836).

Temporal Representation:

Data for this waterbody was collected over the date range 2011-11-01 to 2020-02-18

Environmental Conditions:

QAPP Information:

IEUA. 2019. Laboratory Quality Assurance Manual.

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 133165, Dieldrin	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239136

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Evaluation Guideline:

The evaluation guideline for dieldrin is the probable effect concentration (PEC) of 61.8 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2017-05-16

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.


DECISION ID	132375	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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 132375, Disulfoton	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

234758

Pollutant:

Disulfoton

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:

Of the two samples collected, none exceeded the guidelines.

Data Reference:

Concentrations of Pesticides in the waterbodies in the Santa Ana Region

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The concentration of toxic substance in the water column, sediments or biota shall not adversely affect beneficial uses (SARWQCB, 1995).

Objective/Criterion Reference:

Water Quality Control Plan for the Santa Ana River Basin

Evaluation Guideline:

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

Guideline Reference:

Spatial Representation:

Temporal Representation:

The samples were collected on 8/7/00 and 8/11/00.

Environmental Conditions:

QAPP Information:

The data's quality is deemed appropriate because it was submitted by the Department of Pesticide Regulation.

QAPP Information Reference(s):


DECISION ID	133166	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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

Line of Evidence (LOE) for Decision ID 133166, Endosulfan sulfate	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239703

Pollutant:

Endosulfan sulfate

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 eSMR_IEUA Regional Plant No. 5 data for Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel) to determine beneficial use support and the results are as follows: 0 of the 8 samples exceeded the water quality threshold for Endosulfan Sulfate. Although a total of 9 samples were collected, 1 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:

WQ data from the California Integrated Water Quality System (CIWQS) 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 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 (745836).

Temporal Representation:

Data for this waterbody was collected over the date range 2011-11-01 to 2020-02-18

Environmental Conditions:

QAPP Information:

IEUA. 2019. Laboratory Quality Assurance Manual.

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	133167	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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

Line of Evidence (LOE) for Decision ID 133167, Endrin	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239159

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Evaluation Guideline:

The evaluation guideline for endrin is the probable effect concentration (PEC) of 207 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2015-05-05

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 133167, Endrin	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239706

Pollutant:

Endrin

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 eSMR_IEUA Regional Plant No. 5 data for Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel) to determine beneficial use support and the results are as follows: 0 of the 8 samples exceeded the water quality threshold for Endrin. Although a total of 9 samples were collected, 1 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:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 8.

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 (745836).

Temporal Representation:

Data for this waterbody was collected over the date range 2011-11-01 to 2020-02-18

Environmental Conditions:

QAPP Information:

IEUA. 2019. Laboratory Quality Assurance Manual.

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	133202	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

Pollutant:	Esfenvalerate/Fenvalerate
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 133202, Esfenvalerate/Fenvalerate	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239217

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Evaluation Guideline:

The evaluation guideline for esfenvalerate/fenvalerate is the median lethal concentration (LC50) of 1.5 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.5 ug/g is the geometric mean of LC50 values for esfenvalerate/fenvalerate (Amweg et al., 2005).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2016-05-19

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.


DECISION ID	133201	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

Pollutant:	Fenpropathrin
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 133201, Fenpropathrin	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239239

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Evaluation Guideline:

The evaluation guideline for fenpropathrin is the median lethal concentration (LC50) of 1 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1 ug/g is the geometric mean of LC50 values for fenpropathrin from Ding et al., ( 2011).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2016-05-19

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.


DECISION ID	133190	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 133190, Fipronil	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239242

Pollutant:

Fipronil

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

Effect of sediment-associated pyrethroids, fipronil, and metabolites on Chironomus tentans growth rate, body mass, condition index, immobilization, and survival. Environ. Toxicol. Chem. 27(12):2582-2590.

Evaluation Guideline:

The evaluation guideline for fipronil is the median lethal concentration (LC50) of 0.13 ug/g and is normalized by the percentage of organic carbon in the sediment sample (Maul et al., 2008).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-05-05 to 2019-05-30

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.


DECISION ID	133203	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 133203, Fipronil Sulfide	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239281

Pollutant:

Fipronil Sulfide

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

The evaluation guideline for fipronil sulfide is the median lethal concentration (LC50) of 0.16 ug/g and is normalized by the percentage of organic carbon in the sediment sample (Maul et al., 2008).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-05-05 to 2019-05-30

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	133204	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 133204, Fipronil Sulfone	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239304

Pollutant:

Fipronil Sulfone

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

The evaluation guideline for fipronil sulfone is the median lethal concentration (LC50) of 0.12 ug/g and is normalized by the percentage of organic carbon in the sediment sample (Maul et al., 2008).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-05-05 to 2019-05-30

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	133168	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 133168, Fluoranthene	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239325

Pollutant:

Fluoranthene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Evaluation Guideline:

The evaluation guideline for fluoranthene is the probable effect concentration (PEC) of 2230 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2019-05-30

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.


DECISION ID	133169	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 133169, Fluorene	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239326

Pollutant:

Fluorene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Evaluation Guideline:

The evaluation guideline for fluorene is the probable effect concentration (PEC) for Fluorene is 536 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2019-05-30

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.


DECISION ID	133191	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. One line of evidence is available in the administrative record to assess this pollutant. Thirty-one of the 43 samples exceed the Hardness as CaCO3 Objective. The Water Board has not yet undertaken the evaluation of information in the Integrated Report record to determine that the exceedances are the result of controllable water quality factors, which means there is insufficient information to conclude the objectives are exceeded as a result of controllable water quality factors. However, the number of exceedances out of the number of samples, using the Listing Policy binomial distribution, indicate beneficial uses may be potentially threatened. Therefore, as an interim approach until waterbody-specific information on controllable water quality factors is evaluated or added to the record, the weight of evidence indicates that there is sufficient justification against placing this waterbody-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. Thirty-one of 43 samples exceed the Hardness as CaCO3 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. 5. Pursuant to page 4-10 of the Santa Ana Water Board Basin Plan: The dissolved mineral content of the waters of the region, as measured by the total dissolved solids test (“Standard Methods for the Examination of Water and Wastewater, 16th Ed.,” 1985: 209B (180°C), p. 95), shall not exceed the specific objectives listed in Table 4-1 as a result of controllable water quality factors.

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 and instead placed in Category 3 because waterbody-specific information on controllable water quality factors has not been evaluated or added to the record.

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 and instead placed in Category 3 because waterbody-specific information on controllable water quality factors has not been evaluated or added to the record.

Line of Evidence (LOE) for Decision ID 133191, Hardness as CaCO3	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239731

Pollutant:

Hardness as CaCO3

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:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 8.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Site-Specific Objective: The concentration of Hardness shall not exceed 240 mg/L in this waterbody (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 (745836)

Temporal Representation:

The samples were collected between the dates of 2011-04-06 and 2020-10-07

Environmental Conditions:

QAPP Information:

IEUA QA documents

QAPP Information Reference(s):

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 8.


DECISION ID	133170	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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:	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 133170, Heptachlor	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239710

Pollutant:

Heptachlor

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 eSMR_IEUA Regional Plant No. 5 data for Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Heptachlor. Although a total of 9 samples were collected, 9 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: 745836 (R-003D).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-11-01 to 2020-02-18

Environmental Conditions:

QAPP Information:

IEUA. 2019. Laboratory Quality Assurance Manual.

QAPP Information Reference(s):

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 8.


DECISION ID	133171	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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:	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 133171, Heptachlor epoxide	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239711

Pollutant:

Heptachlor epoxide

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 eSMR_IEUA Regional Plant No. 5 data for Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Heptachlor Epoxide. Although a total of 9 samples were collected, 9 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: 745836 (R-003D).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-11-01 to 2020-02-18

Environmental Conditions:

QAPP Information:

IEUA. 2019. Laboratory Quality Assurance Manual.

QAPP Information Reference(s):


DECISION ID	132377	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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

Line of Evidence (LOE) for Decision ID 132377, Lead	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

234807

Pollutant:

Lead

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:

The sample did not exceeded the standard.

Data Reference:

Water Quality Control Plan for the Santa Ana River Basin

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The concentration of toxic substance in the water column, sediments or biota shall not adversely affect beneficial uses (SARWQCB, 1995).

Objective/Criterion Reference:

Evaluation Guideline:

The California Toxics Rule criteria for lead (hardness dependent): 10.32 ppb.

Guideline Reference:

Spatial Representation:

The sample was taken in Chino Creek at Pine Avenue.

Temporal Representation:

The sample was taken on 8/16/2005.

Environmental Conditions:

QAPP Information:

The data's quality is deemed acceptable because it was submitted by an NPDES discharger in accordance with its Monitoring and Reporting Requirements.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 132377, Lead	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239224

Pollutant:

Lead

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Evaluation Guideline:

The evaluation guideline for lead is the probable effect concentration (PEC) of 128 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2018-05-21

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 132377, Lead	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239732

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ data from the California Integrated Water Quality System (CIWQS) 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 (745836)

Temporal Representation:

The samples were collected between the dates of 2011-06-08 and 2020-02-18

Environmental Conditions:

QAPP Information:

IEUA QA documents

QAPP Information Reference(s):

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 8.


DECISION ID	133172	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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 133172, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239707

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

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 eSMR_IEUA Regional Plant No. 5 data for Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel) to determine beneficial use support and the results are as follows: 0 of the 8 samples exceeded the water quality threshold for HCH, gamma-. Although a total of 9 samples were collected, 1 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 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 (745836).

Temporal Representation:

Data for this waterbody was collected over the date range 2011-11-01 to 2020-02-18

Environmental Conditions:

QAPP Information:

IEUA. 2019. Laboratory Quality Assurance Manual.

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 133172, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239365

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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 Stream Pollution Trends data for Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel) to determine beneficial use support and the results are as follows: 0 of the 2 samples exceeded the evaluation guideline for HCH, gamma-. Although a total of 4 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective 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:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Evaluation Guideline:

The evaluation guideline for lindane is the probable effect concentration (PEC) for Lindane is 4.99 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2015-05-05

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.


DECISION ID	132378	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 132378, Malathion	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

234759

Pollutant:

Malathion

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:

Of the two samples collected, none exceeded the guidelines.

Data Reference:

Concentrations of Pesticides in the waterbodies in the Santa Ana Region

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The concentration of toxic substance in the water column, sediments or biota shall not adversely affect beneficial uses (SARWQCB, 1995).

Objective/Criterion Reference:

Water Quality Control Plan for the Santa Ana River Basin

Evaluation Guideline:

USEPA National Recommended Water Quality Criteria Aquatic Life Protection Instantaneous Max for malathion: 0.01 ppb.

Guideline Reference:

Spatial Representation:

Temporal Representation:

The samples were collected on 8/7/00 and 8/11/00.

Environmental Conditions:

QAPP Information:

The data's quality is deemed appropriate because it was submitted by the Department of Pesticide Regulation.

QAPP Information Reference(s):


DECISION ID	149093	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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 149093, Mercury	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

234803

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:

The only sample collected did not exceed the guideline.

Data Reference:

Water Quality Control Plan for the Santa Ana River Basin

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The concentration of toxic substance in the water column, sediments or biota shall not adversely affect beneficial uses (SARWQCB, 1995).

Objective/Criterion Reference:

Evaluation Guideline:

USEPA National Recommended Ambient Water Quality Criteria for Aquatic life protection for mercury: 0.77 ppb.

Guideline Reference:

Spatial Representation:

The sample was collected in Chino Creek at Pine Avenue.

Temporal Representation:

The sample was collected on August 16, 2005.

Environmental Conditions:

QAPP Information:

The data's quality is deemed acceptable because it was submitted by an NPDES discharger in accordance with its Monitoring and Reporting Requirements.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 149093, Mercury	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239274

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Evaluation Guideline:

The evaluation guideline for mercury is the probable effect concentration (PEC) of 1.06 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2012-05-09 to 2020-06-09

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.


DECISION ID	133173	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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

Line of Evidence (LOE) for Decision ID 133173, Methyl Parathion	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239536

Pollutant:

Methyl Parathion

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Evaluation Guideline:

The evaluation guideline for methyl parathion is the median lethal concentration (LC50) of 6 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 6 ug/g is the geometric mean of LC50 values for methyl parathion from Ding et al., (2011).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2015-05-05

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.


DECISION ID	132379	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

Pollutant:	Molinate
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 132379, Molinate	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

234760

Pollutant:

Molinate

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:

Of the two samples collected, none exceeded the guidelines.

Data Reference:

Concentrations of Pesticides in the waterbodies in the Santa Ana Region

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The concentration of toxic substance in the water column, sediments or biota shall not adversely affect beneficial uses (SARWQCB, 1995).

Objective/Criterion Reference:

Water Quality Control Plan for the Santa Ana River Basin

Evaluation Guideline:

California Department of Fish and Game for molinate: 13 ppb.

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

Spatial Representation:

Temporal Representation:

The samples were collected on 8/7/00 and 8/11/00.

Environmental Conditions:

QAPP Information:

The data's quality is deemed appropriate because it was submitted by the Department of Pesticide Regulation.

QAPP Information Reference(s):


DECISION ID	133174	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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

Line of Evidence (LOE) for Decision ID 133174, Naphthalene	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239173

Pollutant:

Naphthalene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Evaluation Guideline:

The evaluation guideline for naphthalene is the probable effect concentration (PEC) of 561 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2019-05-30

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 133174, Naphthalene	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239626

Pollutant:

Naphthalene

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:

WQ data from the California Integrated Water Quality System (CIWQS) 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:

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: 745836 (R-003D).

Temporal Representation:

The samples were collected between the dates of 2011-11-01 and 2020-02-18

Environmental Conditions:

QAPP Information:

IEUA. 2019. Laboratory Quality Assurance Manual.

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	132380	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 132380, Nickel	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239235

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Evaluation Guideline:

The evaluation guideline for nickel is the probable effect concentration (PEC) of 48.6 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2018-05-21

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 132380, Nickel	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

234808

Pollutant:

Nickel

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:

The sample did not exceeded the standard.

Data Reference:

Water Quality Control Plan for the Santa Ana River Basin

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The concentration of toxic substance in the water column, sediments or biota shall not adversely affect beneficial uses (SARWQCB, 1995).

Objective/Criterion Reference:

Evaluation Guideline:

The California Toxics Rule criteria for nickel (hardness dependent): 114.01 ppb.

Guideline Reference:

Spatial Representation:

The sample was taken in Chino Creek at Pine Avenue.

Temporal Representation:

The sample was taken on 8/16/2005.

Environmental Conditions:

QAPP Information:

The data's quality is deemed acceptable because it was submitted by an NPDES discharger in accordance with its Monitoring and Reporting Requirements.

QAPP Information Reference(s):


DECISION ID	150886	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

Pollutant:	Nitrogen
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. Three lines of evidence are available in the administrative record to assess this pollutant. Seven of the 42 samples exceed the Total Inorganic Nitrogen objective. This assessment utilized a 7-day averaging period instead of an annual flow-weighted average. Please see the staff report for more information. The Water Board has not yet undertaken the evaluation of information in the Integrated Report record to determine that the exceedances are the result of controllable water quality factors, which means there is insufficient information to conclude the objectives are exceeded as a result of controllable water quality factors. However, the number of exceedances out of the number of samples, using the Listing Policy binomial distribution, indicate beneficial uses may be potentially threatened. Therefore, as an interim approach until waterbody-specific information on controllable water quality factors is evaluated or added to the record, the weight of evidence indicates that there is sufficient justification against placing this waterbody-pollutant combination on the CWA Section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Seven of the 42 samples exceed the Total Inorganic Nitrogen objective, and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. 5. Pursuant to page 4-10 of the Santa Ana Water Board Basin Plan: The dissolved mineral content of the waters of the region, as measured by the total dissolved solids test (“Standard Methods for the Examination of Water and Wastewater, 16th Ed.,” 1985: 209B (180°C), p. 95), shall not exceed the specific objectives listed in Table 4-1 as a result of controllable water quality factors.

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 and instead placed in Category 3 because waterbody-specific information on controllable water quality factors has not been evaluated or added to the record.

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 and instead placed in Category 3 because waterbody-specific information on controllable water quality factors has not been evaluated or added to the record.

Line of Evidence (LOE) for Decision ID 150886, Nitrogen	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

7897

Pollutant:

Total Nitrogen as N

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Groundwater Recharge

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Of the 42 samples collected 7 exceeded the objective.

Data Reference:

Water Quality Control Plan for the Santa Ana River Basin

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Santa Ana Region's Basin Plan Objective: Total Inorganic Nitrogen: 8 mg/l

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at one station at Pine Ave.

Temporal Representation:

The samples were collected several times per month since 4/6/2006 through 2/22/2007

Environmental Conditions:

QAPP Information:

The data's quality is deemed appropriate because it originated from an NPDES discharger in compliance with their monitoring and reporting program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 150886, Nitrogen	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

81369

Pollutant:

Total Nitrogen as N

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:

The sample did not exceed the Total Nitrogen water quality objective at 8 mg/L. The datum is reported as underneath the quantitation limit. This quantitation limit is less than or equal to the water quality standard, the value will be considered as meeting the water quality standard, objective, criterion, or evaluation guideline.

Data Reference:

Data for Various Pollutants in the Streams of Region 8, 2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Table 4-1 of the Santa Ana Basin Plan (1995) states that the water quality objective for Total Nitrogen for Santa Ana River (Reach 3), is 8 mg/L.

Objective/Criterion Reference:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 8.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Sample was collected at 'SMCR8_197, Chino Creek (Reach 1B).

Temporal Representation:

Sample was collected on 6/4/2009.

Environmental Conditions:

QAPP Information:

No quality assurance information was provided.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 150886, Nitrogen	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

303370

Pollutant:

Total Nitrogen as N

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:

Site-Specific Objective: The concentration of Total Inorganic Nitrogen shall not exceed 8 mg/L in this waterbody (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 (745836)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2016-07-06

Environmental Conditions:

QAPP Information:

IEUA. 2019. Laboratory Quality Assurance Manual.

QAPP Information Reference(s):

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


DECISION ID	133175	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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. Nine lines of evidence are available in the administrative record to assess this pollutant. Fifty-one of the 532 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. Fifty-one of 532 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:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 133175, Oxygen, Dissolved	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

236803

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 Middle Santa Ana River TMDL Monitoring Project data for Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel) to determine beneficial use support and results are as follows: 1 of 41 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: 801MSC7 (Chino Creek at Central Avenue).

Temporal Representation:

The samples were collected between the dates of 2014-05-20 and 2019-09-03

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 133175, Oxygen, Dissolved	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

237132

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 Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel) to determine beneficial use support and results are as follows: 12 of 61 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: 801MSC7 (Chino Creek at Central Avenue).

Temporal Representation:

The samples were collected between the dates of 2016-03-06 and 2018-03-03

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 133175, Oxygen, Dissolved	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

236826

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 Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel) to determine beneficial use support and results are as follows: 4 of 44 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: 801MSC3 (Prado Park Lake Outlet).

Temporal Representation:

The samples were collected between the dates of 2016-03-06 and 2018-03-03

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 133175, Oxygen, Dissolved	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

236825

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

114

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Middle Santa Ana River TMDL Monitoring Project data for Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel) to determine beneficial use support and results are as follows: 13 of 114 samples exceeded the water quality threshold for Oxygen, Dissolved.

Data Reference:

Field, Habitat, 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: 801MSC3 (Prado Park Lake Outlet).

Temporal Representation:

The samples were collected between the dates of 2010-08-31 and 2014-03-04

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 133175, Oxygen, Dissolved	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

237444

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

115

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Middle Santa Ana River TMDL Monitoring Project data for Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel) to determine beneficial use support and results are as follows: 4 of 115 samples exceeded the water quality threshold for Oxygen, Dissolved.

Data Reference:

Field, Habitat, 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: 801MSC7 (Chino Creek at Central Avenue).

Temporal Representation:

The samples were collected between the dates of 2010-08-31 and 2014-03-04

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 133175, Oxygen, Dissolved	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

237173

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 Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel) to determine beneficial use support and results are as follows: 12 of 58 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: 801MSC7 (Chino Creek at Central Avenue).

Temporal Representation:

The samples were collected between the dates of 2018-05-09 and 2020-03-16

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 133175, Oxygen, Dissolved	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

236862

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 Middle Santa Ana River TMDL Monitoring Project data for Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel) to determine beneficial use support and results are as follows: 5 of 35 samples exceeded the water quality threshold for Oxygen, Dissolved.

Data Reference:

Field, Habitat, 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: 801MSC3 (Prado Park Lake Outlet).

Temporal Representation:

The samples were collected between the dates of 2014-05-20 and 2015-03-04

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 133175, Oxygen, Dissolved	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

236901

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: 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

The samples were collected between the dates of 2014-05-14 and 2019-06-19

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 133175, Oxygen, Dissolved	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

237199

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 Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel) to determine beneficial use support and results are as follows: 0 of 57 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: 801MSC3 (Prado Park Lake Outlet).

Temporal Representation:

The samples were collected between the dates of 2018-05-09 and 2020-03-16

Environmental Conditions:

QAPP Information:

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

QAPP Information Reference(s):


DECISION ID	149187	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

Pollutant:	PAHs (Polycyclic Aromatic Hydrocarbons)
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 149187, PAHs (Polycyclic Aromatic Hydrocarbons)	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239507

Pollutant:

PAHs (Polycyclic Aromatic Hydrocarbons)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Evaluation Guideline:

The evaluation guideline for total PAHs is the probable effect concentration (PEC) of 22800 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2019-05-30

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.


DECISION ID	133180	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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:	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 133180, PCBs (Polychlorinated biphenyls)	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239464

Pollutant:

PCBs (Polychlorinated biphenyls)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Evaluation Guideline:

The evaluation guideline for total PCBs is the probable effect concentration (PEC) of 676 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2017-05-16

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.


DECISION ID	132381	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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 132381, Parathion	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

234773

Pollutant:

Parathion

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:

Of the two samples collected, none exceeded the guidelines.

Data Reference:

Concentrations of Pesticides in the waterbodies in the Santa Ana Region

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The concentration of toxic substance in the water column, sediments or biota shall not adversely affect beneficial uses (SARWQCB, 1995).

Objective/Criterion Reference:

Water Quality Control Plan for the Santa Ana River Basin

Evaluation Guideline:

California Department of Fish and Game for parathion: 0.08 ppb.

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

Spatial Representation:

Temporal Representation:

The samples were collected on 8/7/00 and 8/11/00.

Environmental Conditions:

QAPP Information:

The data's quality is deemed appropriate because it was submitted by the Department of Pesticide Regulation.

QAPP Information Reference(s):


DECISION ID	133177	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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 133177, Pentachlorophenol (PCP)	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239632

Pollutant:

Pentachlorophenol (PCP)

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:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 8.

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: 745836 (R-003D).

Temporal Representation:

The samples were collected between the dates of 2011-11-01 and 2020-02-18

Environmental Conditions:

QAPP Information:

IEUA. 2019. Laboratory Quality Assurance Manual.

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	133205	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

Pollutant:	Permethrin
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 133205, Permethrin	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239476

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Evaluation Guideline:

The evaluation guideline for permethrin is the median lethal concentration (LC50) of 8.9 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 8.9 ug/g is the geometric mean of LC50 values for permethrin (Amweg et al., 2005).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2019-05-30

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.


DECISION ID	133179	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

Pollutant:	Phenanthrene
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 133179, Phenanthrene	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239495

Pollutant:

Phenanthrene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Evaluation Guideline:

The evaluation guideline for phenanthrene is the probable effect concentration (PEC) of 1170 ug/kg dry weight (MacDonald et al.).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2019-05-30

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.


DECISION ID	133181	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

Pollutant:	Pyrene
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 133181, Pyrene	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239622

Pollutant:

Pyrene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Evaluation Guideline:

The evaluation guideline for pyrene is the probable effect concentration (PEC) of 1520 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2019-05-30

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.


DECISION ID	132382	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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 132382, Selenium	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

234804

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:

The only sample collected did not exceed the guideline.

Data Reference:

Water Quality Control Plan for the Santa Ana River Basin

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The concentration of toxic substance in the water column, sediments or biota shall not adversely affect beneficial uses (SARWQCB, 1995).

Objective/Criterion Reference:

Evaluation Guideline:

California Toxics Rule Fresh Water Aquatic Life Protection 4-day average continuous concentration for selenium: 20 ppb.

Guideline Reference:

Compilation of Water Quality Goals

Spatial Representation:

The sample was collected in Chino Creek at Pine Avenue.

Temporal Representation:

The sample was collected on August 16, 2005.

Environmental Conditions:

QAPP Information:

The data's quality is deemed acceptable because it was submitted by an NPDES discharger in accordance with its Monitoring and Reporting Requirements.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 132382, Selenium	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239646

Pollutant:

Selenium

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:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 8.

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: 745836 (R-003D).

Temporal Representation:

The samples were collected between the dates of 2011-06-08 and 2020-02-18

Environmental Conditions:

QAPP Information:

IEUA. 2019. Laboratory Quality Assurance Manual.

QAPP Information Reference(s):

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 8.

Line of Evidence (LOE) for Decision ID 132382, Selenium	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239650

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: 745836 (R-003D).

Temporal Representation:

The samples were collected between the dates of 2011-06-08 and 2020-02-18

Environmental Conditions:

QAPP Information:

IEUA. 2019. Laboratory Quality Assurance Manual.

QAPP Information Reference(s):

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 8.


DECISION ID	132383	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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 132383, Silver	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239653

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: 745836 (R-003D).

Temporal Representation:

The samples were collected between the dates of 2011-06-08 and 2020-02-18

Environmental Conditions:

QAPP Information:

IEUA. 2019. Laboratory Quality Assurance Manual.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 132383, Silver	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

234809

Pollutant:

Silver

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:

The sample did not exceeded the standard.

Data Reference:

Water Quality Control Plan for the Santa Ana River Basin

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The concentration of toxic substance in the water column, sediments or biota shall not adversely affect beneficial uses (SARWQCB, 1995).

Objective/Criterion Reference:

Evaluation Guideline:

The California Toxics Rule criteria for silver (hardness dependent): 19.90 ppb.

Guideline Reference:

Spatial Representation:

The sample was taken in Chino Creek at Pine Avenue.

Temporal Representation:

The sample was taken on 8/16/2005.

Environmental Conditions:

QAPP Information:

The data's quality is deemed acceptable because it was submitted by an NPDES discharger in accordance with its Monitoring and Reporting Requirements.

QAPP Information Reference(s):


DECISION ID	132384	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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 132384, Simazine	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

234774

Pollutant:

Simazine

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:

Of the two samples collected, none exceeded the guidelines.

Data Reference:

Concentrations of Pesticides in the waterbodies in the Santa Ana Region

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The concentration of toxic substance in the water column, sediments or biota shall not adversely affect beneficial uses (SARWQCB, 1995).

Objective/Criterion Reference:

Water Quality Control Plan for the Santa Ana River Basin

Evaluation Guideline:

USEPA National Recommended Water Quality Criteria Aquatic Life Protection Instantaneous Max for simazine: 10 ppb.

Guideline Reference:

Spatial Representation:

Temporal Representation:

The samples were collected on 8/7/00 and 8/11/00.

Environmental Conditions:

QAPP Information:

The data's quality is deemed appropriate because it was submitted by the Department of Pesticide Regulation.

QAPP Information Reference(s):


DECISION ID	133182	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

Pollutant:	Sodium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Two lines of evidence are available in the administrative record to assess this pollutant. 219 of the 276 samples exceed the Sodium objective. This assessment utilized a 7-day averaging period instead of an annual flow-weighted average. Please see the staff report for more information. The Water Board has not yet undertaken the evaluation of information in the Integrated Report record to determine that the exceedances are the result of controllable water quality factors, which means there is insufficient information to conclude the objectives are exceeded as a result of controllable water quality factors. However, the number of exceedances out of the number of samples, using the Listing Policy binomial distribution, indicate beneficial uses may be potentially threatened. Therefore, as an interim approach until waterbody-specific information on controllable water quality factors is evaluated or added to the record, the weight of evidence indicates that there is sufficient justification against placing this waterbody-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. 219 of the 276 samples exceed the Sodium 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. 5. Pursuant to page 4-10 of the Santa Ana Water Board Basin Plan: The dissolved mineral content of the waters of the region, as measured by the total dissolved solids test (“Standard Methods for the Examination of Water and Wastewater, 16th Ed.,” 1985: 209B (180°C), p. 95), shall not exceed the specific objectives listed in Table 4-1 as a result of controllable water quality factors. Previous decision language below: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One (1) line of evidence is available in the administrative record to assess this pollutant. Two hundred and seven (207) of the samples exceed the water quality 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 section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Two hundred-seven (207) of two hundred sixty-one (261) samples exceeded the Basin Plan Objective and this does exceed the allowable frequency listed in Table 3.2 of the Listing Policy. However, the GWR beneficial use is more correctly assessed using actual groundwater data. The surface water objective for this mineral constituent was tied to groundwater objectives for this constituent that were deleted from the Basin Plan (Resolution No. R8-2004-0001). Stakeholders have indicated their intent to re-visit the appropriateness of the surface water objectives for this and other individual mineral objectives as part of the ongoing TDS/Nitrogen Task Force. 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 and instead placed in Category 3 because waterbody-specific information on controllable water quality factors has not been evaluated or added to the record.

State Board Review of Regional Board Conclusion and Recommendation:	Previous decision language below: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One (1) line of evidence is available in the administrative record to assess this pollutant. Two hundred and seven (207) of the samples exceed the water quality 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 section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Two hundred-seven (207) of two hundred sixty-one (261) samples exceeded the Basin Plan Objective and this does exceed the allowable frequency listed in Table 3.2 of the Listing Policy. However, the GWR beneficial use is more correctly assessed using actual groundwater data. The surface water objective for this mineral constituent was tied to groundwater objectives for this constituent that were deleted from the Basin Plan (Resolution No. R8-2004-0001). Stakeholders have indicated their intent to re-visit the appropriateness of the surface water objectives for this and other individual mineral objectives as part of the ongoing TDS/Nitrogen Task Force. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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 and instead placed in Category 3 because waterbody-specific information on controllable water quality factors has not been evaluated or added to the record.

Line of Evidence (LOE) for Decision ID 133182, Sodium	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239735

Pollutant:

Sodium

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:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 8.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Site-Specific Objective: The concentration of Sodium shall not exceed 75 mg/L in this waterbody (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 (745836)

Temporal Representation:

The samples were collected between the dates of 2011-06-08 and 2020-10-07

Environmental Conditions:

QAPP Information:

IEUA QA documents

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 133182, Sodium	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

7892

Pollutant:

Sodium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Groundwater Recharge

Number of Samples:

261

Number of Exceedances:

207

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Of the 261 samples collected, 207 exceeded the Basin Plan's Objective.

Data Reference:

Water Quality Control Plan for the Santa Ana River Basin

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Santa Ana Region's Basin Plan site specific objective: 75 mg/l

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at one station at Pine Avenue.

Temporal Representation:

The samples were collected monthly since November 1990 through February 2007

Environmental Conditions:

QAPP Information:

The data's quality is deemed appropriate because it originated from an NPDES discharger in compliance with their monitoring and reporting program.

QAPP Information Reference(s):


DECISION ID	133183	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

Pollutant:	Sulfates
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Two lines of evidence are available in the administrative record to assess this pollutant. 155 of the 188 samples exceed the Sulfates objective. This assessment utilized a 7-day averaging period instead of an annual flow-weighted average. Please see the staff report for more information. The Water Board has not yet undertaken the evaluation of information in the Integrated Report record to determine that the exceedances are the result of controllable water quality factors, which means there is insufficient information to conclude the objectives are exceeded as a result of controllable water quality factors. However, the number of exceedances out of the number of samples, using the Listing Policy binomial distribution, indicate beneficial uses may be potentially threatened. Therefore, as an interim approach until waterbody-specific information on controllable water quality factors is evaluated or added to the record, the weight of evidence indicates that there is sufficient justification against placing this waterbody-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. 155 of the 188 samples exceed the Sulfates 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. 5. Pursuant to page 4-10 of the Santa Ana Water Board Basin Plan: The dissolved mineral content of the waters of the region, as measured by the total dissolved solids test (“Standard Methods for the Examination of Water and Wastewater, 16th Ed.,” 1985: 209B (180°C), p. 95), shall not exceed the specific objectives listed in Table 4-1 as a result of controllable water quality factors. Previous decision language below: This pollutant is being considered for placement on the CWA section 303(d) List under section three (3) of the Listing Policy. Under section 3.1, a single line of evidence is necessary to assess listing status. One (1) line of evidence is available in the administrative record to assess this pollutant. One hundred fifty-four (154) of the one hundred eighty-four (184) samples exceed this site specific antidegradation objective, found in Table 4-1 of the Region 8 Basin Plan. While this number of exceedances would normally provide sufficient justification in favor of placing this water segment-pollutant combination on the CWA section 303(d) List, none of the exceedances would cause an impairment of any of the beneficial uses assigned to this waterbody (REC1, REC2, WARM, WILD, RARE). Table 4-1 of the Region 8 Basin Plan identifies site specific water quality objectives based on historical values of Total Dissolved Solids, Hardness, Sodium, Chloride, Total Inorganic Nitrogen, Sulfate and Chemical Oxygen Demand, that were intended to be protective of the groundwater aquifers underlying those surface waterbodies identified in Table 4-1. Regional Board staff have recognized that the Groundwater Recharge beneficial use is more correctly assessed using actual groundwater data rather than by monitoring surface waters. Region Board Resolution No. R8-2004-0001 deleted the groundwater objectives for individual minerals from the Basin Plan, but not the individual mineral objectives for all surface waters. Therefore, as no designated beneficial uses of this waterbody segment are being impaired by these exceedances, the weight of evidence supports a decision to not list this waterbody segment ¿ pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. One hundred fifty-four (154) of the one hundred eighty-four (184) samples exceed the beneficial use criterion 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. 5. Weight of evidence supports the conclusion that the exceedances are not impairing any designated beneficial uses for this waterbody segment.

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 and instead placed in Category 3 because waterbody-specific information on controllable water quality factors has not been evaluated or added to the record.

State Board Review of Regional Board Conclusion and Recommendation:	Previous decision language below: This pollutant is being considered for placement on the CWA section 303(d) List under section three (3) of the Listing Policy. Under section 3.1, a single line of evidence is necessary to assess listing status. One (1) line of evidence is available in the administrative record to assess this pollutant. One hundred fifty-four (154) of the one hundred eighty-four (184) samples exceed this site specific antidegradation objective, found in Table 4-1 of the Region 8 Basin Plan. While this number of exceedances would normally provide sufficient justification in favor of placing this water segment-pollutant combination on the CWA section 303(d) List, none of the exceedances would cause an impairment of any of the beneficial uses assigned to this waterbody (REC1, REC2, WARM, WILD, RARE). Table 4-1 of the Region 8 Basin Plan identifies site specific water quality objectives based on historical values of Total Dissolved Solids, Hardness, Sodium, Chloride, Total Inorganic Nitrogen, Sulfate and Chemical Oxygen Demand, that were intended to be protective of the groundwater aquifers underlying those surface waterbodies identified in Table 4-1. Regional Board staff have recognized that the Groundwater Recharge beneficial use is more correctly assessed using actual groundwater data rather than by monitoring surface waters. Region Board Resolution No. R8-2004-0001 deleted the groundwater objectives for individual minerals from the Basin Plan, but not the individual mineral objectives for all surface waters. Therefore, as no designated beneficial uses of this waterbody segment are being impaired by these exceedances, the weight of evidence supports a decision to not list this waterbody segment ¿ pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. One hundred fifty-four (154) of the one hundred eighty-four (184) samples exceed the beneficial use criterion 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. 5. Weight of evidence supports the conclusion that the exceedances are not impairing any designated beneficial uses for this waterbody segment.

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 and instead placed in Category 3 because waterbody-specific information on controllable water quality factors has not been evaluated or added to the record.

Line of Evidence (LOE) for Decision ID 133183, Sulfates	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239736

Pollutant:

Sulfates

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:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 8.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Site-Specific Objective: The concentration of Sulfate shall not exceed 60 mg/L in this waterbody (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 (745836)

Temporal Representation:

The samples were collected between the dates of 2011-06-08 and 2011-09-07

Environmental Conditions:

QAPP Information:

IEUA QA documents

QAPP Information Reference(s):

Data for Metals and Other Inorganic Pollutants in Orange County Water District, 1994-2010.

Line of Evidence (LOE) for Decision ID 133183, Sulfates	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

81366

Pollutant:

Sulfates

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

184

Number of Exceedances:

154

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Numeric data generated from 184 samples collected had 154 exceedences of the site-specific objective.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The site-pecific objective for Sulfates at Chino Creek Reach 1B according to table 4-1 of the Santa Ana Basin plan is 60 mg/L.

Objective/Criterion Reference:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 8.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data was collected from the CK-CHINO-03 station.

Temporal Representation:

Data was collected approximately once a month from February 1994 to August 2009.

Environmental Conditions:

QAPP Information:

The samples were collected under the Orange County Water District Main Laboratory Quality Assurance Manual. November 2009.

QAPP Information Reference(s):


DECISION ID	133184	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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. Under section 3.2 a single line of evidence is necessary to assess listing status. Six lines of evidence are available in the administrative record to assess this pollutant. Two of the 497 samples exceed the WARM temperature 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 the 497 samples exceeded the WARM temperature 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:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 133184, Temperature, water	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239715

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

225

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 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:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 745836 (R-003D).

Temporal Representation:

The samples were collected between the dates of 2011-06-08 and 2020-10-07

Environmental Conditions:

QAPP Information:

IEUA. 2019. Laboratory Quality Assurance Manual.

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 133184, Temperature, water	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

238070

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 Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel) to determine beneficial use support and results are as follows: 0 of 49 samples exceeded the water quality threshold for Temperature.

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: 801MSC3 (Prado Park Lake Outlet).

Temporal Representation:

The samples were collected between the dates of 2016-03-10 and 2020-03-16

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 133184, Temperature, water	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

237852

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 Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel) to determine beneficial use support and results are as follows: 0 of 61 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: 801MSC7 (Chino Creek at Central Avenue).

Temporal Representation:

The samples were collected between the dates of 2016-03-10 and 2020-03-16

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 133184, Temperature, water	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

238071

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:

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: 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

The samples were collected between the dates of 2013-05-16 and 2019-06-19

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 133184, Temperature, water	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

237850

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 Middle Santa Ana River TMDL Monitoring Project data for Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel) to determine beneficial use support and results are as follows: 1 of 78 samples exceeded the water quality threshold for Temperature.

Data Reference:

Field, Habitat, 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: 801MSC7 (Chino Creek at Central Avenue).

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2019-09-03

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 133184, Temperature, water	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

237863

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 Middle Santa Ana River TMDL Monitoring Project data for Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel) to determine beneficial use support and results are as follows: 0 of 76 samples exceeded the water quality threshold for Temperature.

Data Reference:

Field, Habitat, 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: 801MSC3 (Prado Park Lake Outlet).

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2015-03-04

Environmental Conditions:

QAPP Information:

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

QAPP Information Reference(s):


DECISION ID	133185	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 133185, Thallium	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239717

Pollutant:

Thallium

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:

WQ data from the California Integrated Water Quality System (CIWQS) 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 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: 745836 (R-003D).

Temporal Representation:

The samples were collected between the dates of 2011-06-08 and 2020-02-18

Environmental Conditions:

QAPP Information:

IEUA. 2019. Laboratory Quality Assurance Manual.

QAPP Information Reference(s):

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 8.

Line of Evidence (LOE) for Decision ID 133185, Thallium	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239716

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: 745836 (R-003D).

Temporal Representation:

The samples were collected between the dates of 2011-08-03 and 2020-02-18

Environmental Conditions:

QAPP Information:

IEUA. 2019. Laboratory Quality Assurance Manual.

QAPP Information Reference(s):

Concentrations of Pesticides in the waterbodies in the Santa Ana Region


DECISION ID	132385	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

Pollutant:	Thiobencarb/Bolero
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 132385, Thiobencarb/Bolero	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

234775

Pollutant:

Thiobencarb/Bolero

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:

Of the two samples collected, none exceeded the guidelines.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The concentration of toxic substance in the water column, sediments or biota shall not adversely affect beneficial uses (SARWQCB, 1995).

Objective/Criterion Reference:

Water Quality Control Plan for the Santa Ana River Basin

Evaluation Guideline:

California Department of Fish and Game for thiobencarb: 3.1 ppb.

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

Spatial Representation:

Temporal Representation:

The samples were collected on 8/7/00 and 8/11/00.

Environmental Conditions:

QAPP Information:

The data's quality is deemed appropriate because it was submitted by the Department of Pesticide Regulation.

QAPP Information Reference(s):


DECISION ID	133186	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

Pollutant:	Total Dissolved Solids
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Three lines of evidence are available in the administrative record to assess this pollutant. 83 of the 479 samples exceed the Total Dissolved Solids objective. This assessment utilized a 7-day averaging period instead of an annual flow-weighted average. Please see the staff report for more information. The Water Board has not yet undertaken the evaluation of information in the Integrated Report record to determine that the exceedances are the result of controllable water quality factors, which means there is insufficient information to conclude the objectives are exceeded as a result of controllable water quality factors. However, the number of exceedances out of the number of samples, using the Listing Policy binomial distribution, indicate beneficial uses may be potentially threatened. Therefore, as an interim approach until waterbody-specific information on controllable water quality factors is evaluated or added to the record, the weight of evidence indicates that there is sufficient justification against placing this waterbody-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. 83 of the 479 samples exceed the Total Dissolved Solids 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. 5. Pursuant to page 4-10 of the Santa Ana Water Board Basin Plan: The dissolved mineral content of the waters of the region, as measured by the total dissolved solids test (“Standard Methods for the Examination of Water and Wastewater, 16th Ed.,” 1985: 209B (180°C), p. 95), shall not exceed the specific objectives listed in Table 4-1 as a result of controllable water quality factors. Previous decision language below: This pollutant is being considered for placement on the CWA section 303(d) List under section three (3) of the Listing Policy. Under section 3.1, a single line of evidence is necessary to assess listing status. Two (2) lines of evidence are available in the administrative record to assess this pollutant. Seventy nine (79) of the four hundred seventy-two (472) samples exceed this site specific antidegradation objective, found in Table 4-1 of the Region 8 Basin Plan. While this number of exceedances would normally provide sufficient justification in favor of placing this water segment-pollutant combination on the CWA section 303(d) List, none of the exceedances would cause an impairment of any of the beneficial uses assigned to this waterbody (REC1, REC2, WARM, WILD, RARE). Table 4-1 of the Region 8 Basin Plan identifies site specific water quality objectives based on historical values of Total Dissolved Solids, Hardness, Sodium, Chloride, Total Inorganic Nitrogen, Sulfate and Chemical Oxygen Demand, that were intended to be protective of the groundwater aquifers underlying those surface waterbodies identified in Table 4-1. Regional Board staff have recognized that the Groundwater Recharge beneficial use is more correctly assessed using actual groundwater data rather than by monitoring surface waters. Region Board Resolution No. R8-2004-0001 deleted the groundwater objectives for individual minerals from the Basin Plan, but not the individual mineral objectives for all surface waters. Therefore, as no designated beneficial uses of this waterbody segment are being impaired by these exceedances, the weight of evidence supports a decision to not list this waterbody segment ¿ pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Seventy nine (79) of the four hundred seventy-two (472) samples exceed the beneficial use criterion 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. 5. Weight of evidence supports the conclusion that the exceedances are not impairing any designated beneficial uses for this waterbody segment.

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 and instead placed in Category 3 because waterbody-specific information on controllable water quality factors has not been evaluated or added to the record.

State Board Review of Regional Board Conclusion and Recommendation:	Previous decision language below: This pollutant is being considered for placement on the CWA section 303(d) List under section three (3) of the Listing Policy. Under section 3.1, a single line of evidence is necessary to assess listing status. Two (2) lines of evidence are available in the administrative record to assess this pollutant. Seventy nine (79) of the four hundred seventy-two (472) samples exceed this site specific antidegradation objective, found in Table 4-1 of the Region 8 Basin Plan. While this number of exceedances would normally provide sufficient justification in favor of placing this water segment-pollutant combination on the CWA section 303(d) List, none of the exceedances would cause an impairment of any of the beneficial uses assigned to this waterbody (REC1, REC2, WARM, WILD, RARE). Table 4-1 of the Region 8 Basin Plan identifies site specific water quality objectives based on historical values of Total Dissolved Solids, Hardness, Sodium, Chloride, Total Inorganic Nitrogen, Sulfate and Chemical Oxygen Demand, that were intended to be protective of the groundwater aquifers underlying those surface waterbodies identified in Table 4-1. Regional Board staff have recognized that the Groundwater Recharge beneficial use is more correctly assessed using actual groundwater data rather than by monitoring surface waters. Region Board Resolution No. R8-2004-0001 deleted the groundwater objectives for individual minerals from the Basin Plan, but not the individual mineral objectives for all surface waters. Therefore, as no designated beneficial uses of this waterbody segment are being impaired by these exceedances, the weight of evidence supports a decision to not list this waterbody segment ¿ pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Seventy nine (79) of the four hundred seventy-two (472) samples exceed the beneficial use criterion 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. 5. Weight of evidence supports the conclusion that the exceedances are not impairing any designated beneficial uses for this waterbody segment.

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 and instead placed in Category 3 because waterbody-specific information on controllable water quality factors has not been evaluated or added to the record.

Line of Evidence (LOE) for Decision ID 133186, Total Dissolved Solids	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

81368

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

184

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Sixty-one of 184 samples exceeded the objective.

Data Reference:

Data for Metals and Other Inorganic Pollutants in Orange County Water District, 1994-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The site-pecific objective for Total Dissolved Solids at Chino Creek Reach 1B according to table 4-1 of the Santa Ana Basin plan is 550 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data was collected from the CK-CHINO-03 station.

Temporal Representation:

Data was collected approximately once a month from February 1994 to August 2009.

Environmental Conditions:

QAPP Information:

The samples were collected under the Orange County Water District Main Laboratory Quality Assurance Manual. November 2009.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 133186, Total Dissolved Solids	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

7896

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Groundwater Recharge

Number of Samples:

288

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Of the 288 samples collected 18 exceeded the Basin Plan's objective.

Data Reference:

Water Quality Control Plan for the Santa Ana River Basin

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Santa Ana Region's Basin Plan Objective: TDS - 550 mg/l

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at one station at Pine Ave.

Temporal Representation:

The samples were collected several times per month over a period of several years starting with 10/8/1984 through 2/22/2007

Environmental Conditions:

QAPP Information:

The data's quality is deemed appropriate because it originated from an NPDES discharger in compliance with their monitoring and reporting program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 133186, Total Dissolved Solids	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239734

Pollutant:

Total Dissolved Solids

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:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 8.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Site-Specific Objective: The concentration of Total Dissolved Solids shall not exceed 550 mg/L in this waterbody (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 (745836)

Temporal Representation:

The samples were collected between the dates of 2011-07-06 and 2019-11-21

Environmental Conditions:

QAPP Information:

IEUA QA documents

QAPP Information Reference(s):


DECISION ID	132386	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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 132386, Zinc	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

234561

Pollutant:

Zinc

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:

The sample did not exceeded the standard.

Data Reference:

Water Quality Control Plan for the Santa Ana River Basin

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The concentration of toxic substance in the water column, sediments or biota shall not adversely affect beneficial uses (SARWQCB, 1995).

Objective/Criterion Reference:

Evaluation Guideline:

The California Toxics Rule criteria for zinc (hardness dependent): 262.19 ppb.

Guideline Reference:

Spatial Representation:

The sample was taken in Chino Creek at Pine Avenue.

Temporal Representation:

The sample was taken on 8/16/2005.

Environmental Conditions:

QAPP Information:

The data's quality is deemed acceptable because it was submitted by an NPDES discharger in accordance with its Monitoring and Reporting Requirements.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 132386, Zinc	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239404

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Evaluation Guideline:

The evaluation guideline for zinc is the probable effect concentration (PEC) of 459 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2018-05-21

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.


DECISION ID	133163	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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

Line of Evidence (LOE) for Decision ID 133163, alpha-Endosulfan (Endosulfan 1)	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239700

Pollutant:

alpha-Endosulfan (Endosulfan 1)

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 eSMR_IEUA Regional Plant No. 5 data for Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel) to determine beneficial use support and the results are as follows: 0 of the 8 samples exceeded the water quality threshold for Endosulfan I. Although a total of 9 samples were collected, 1 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:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 8.

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 (745836).

Temporal Representation:

Data for this waterbody was collected over the date range 2011-11-01 to 2020-02-18

Environmental Conditions:

QAPP Information:

IEUA. 2019. Laboratory Quality Assurance Manual.

QAPP Information Reference(s):

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 8.


DECISION ID	133176	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

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

Line of Evidence (LOE) for Decision ID 133176, beta-Endosulfan (Endosulfan 2)	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239702

Pollutant:

beta-Endosulfan (Endosulfan 2)

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 eSMR_IEUA Regional Plant No. 5 data for Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel) to determine beneficial use support and the results are as follows: 0 of the 8 samples exceeded the water quality threshold for Endosulfan II. Although a total of 9 samples were collected, 1 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 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 (745836).

Temporal Representation:

Data for this waterbody was collected over the date range 2011-11-01 to 2020-02-18

Environmental Conditions:

QAPP Information:

IEUA. 2019. Laboratory Quality Assurance Manual.

QAPP Information Reference(s):

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


DECISION ID	133178	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

Pollutant:	pH
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Seven lines of evidence are available in the administrative record to assess this pollutant. 167 of the 539 samples exceed the WARM pH objective. The Water Board has not yet undertaken the evaluation of information in the Integrated Report record to determine that the exceedances are the result of controllable water quality factors, which means there is insufficient information to conclude the objectives are exceeded as a result of controllable water quality factors. However, the number of exceedances out of the number of samples, using the Listing Policy binomial distribution, indicate beneficial uses may be potentially threatened. Therefore, as an interim approach until waterbody-specific information on controllable water quality factors is evaluated or added to the record, the weight of evidence indicates that there is sufficient justification against placing this waterbody-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. 167 of the 539 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. 5. Pursuant to page 4-18 of the Santa Ana Water Board Basin Plan: 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.

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 and instead placed in Category 3 because waterbody-specific information on controllable water quality factors has not been evaluated or added to the record.

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 and instead placed in Category 3 because waterbody-specific information on controllable water quality factors has not been evaluated or added to the record.

Line of Evidence (LOE) for Decision ID 133178, pH	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

237304

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 Middle Santa Ana River TMDL Monitoring Project data for Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel) to determine beneficial use support and results are as follows: 49 of 79 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: 801MSC7 (Chino Creek at Central Avenue).

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2019-09-03

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 133178, pH	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

237305

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 Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel) to determine beneficial use support and results are as follows: 29 of 49 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: 801MSC3 (Prado Park Lake Outlet).

Temporal Representation:

The samples were collected between the dates of 2016-03-10 and 2020-03-16

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 133178, pH	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239633

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

225

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ data from the California Integrated Water Quality System (CIWQS) 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: 745836 (R-003D).

Temporal Representation:

The samples were collected between the dates of 2011-06-08 and 2020-10-07

Environmental Conditions:

QAPP Information:

IEUA. 2019. Laboratory Quality Assurance Manual.

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 133178, pH	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

237302

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:

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: 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

The samples were collected between the dates of 2014-05-14 and 2019-06-19

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 133178, pH	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

237193

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 Middle Santa Ana River TMDL Monitoring Project data for Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel) to determine beneficial use support and results are as follows: 45 of 76 samples exceeded the water quality threshold for pH.

Data Reference:

Field, Habitat, 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: 801MSC3 (Prado Park Lake Outlet).

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2015-03-04

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 133178, pH	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

237395

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 Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel) to determine beneficial use support and results are as follows: 0 of 61 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: 801MSC7 (Chino Creek at Central Avenue).

Temporal Representation:

The samples were collected between the dates of 2016-03-10 and 2020-03-16

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 133178, pH	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

7893

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:

Of the 42 field measurements taken none exceeded the Basin Plan's Objective

Data Reference:

Water Quality Control Plan for the Santa Ana River Basin

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Santa Ana Region's Basin Plan Objective: 6.5 - 8.5 pH units

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The field measurements were collected at one station at Pine Ave.

Temporal Representation:

The measurements were taken monthly from 1/18/05 through 2/22/07

Environmental Conditions:

QAPP Information:

The data's quality is deemed appropriate because it originated from an NPDES discharger in compliance with their monitoring and reporting program.

QAPP Information Reference(s):


DECISION ID	133192	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

Pollutant:	Bifenthrin
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 3.6 of the Listing Policy. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with sediment toxicity to justify adding that pollutant to the CWA section 303(d) List. Two lines of evidence are available in the administrative record to assess this pollutant. Seven of the seven sediment samples exceed the WARM Bifenthrin guideline. Eight of 10 samples exhibited sediment toxicity. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification for placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Seven of the seven sediment samples exceed the WARM Bifenthrin guideline. Eight of 10 samples exhibited sediment toxicity and this sample size is sufficient to determine beneficial use support, with the power and confidence of the Listing Policy. There is associated sediment toxicity data as required by Section 3.6 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:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 133192, Bifenthrin	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

238147

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

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:

8 of the 10 samples collected by SWAMP Stream Pollution Trends for Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel) 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: Hyalella azteca for Growth (wt/surv indiv), Hyalella azteca for Survival, Chironomus dilutus for Survival, Chironomus dilutus for Growth (wt/surv indiv). The following tests exhibited toxicity: Hyalella azteca for Survival on 2011-05-25, Hyalella azteca for Survival on 2012-05-09, Hyalella azteca for Growth (wt/surv indiv) on 2012-05-09, Hyalella azteca for Survival on 2013-05-16, Hyalella azteca for Growth (wt/surv indiv) on 2013-05-16, Hyalella azteca for Survival on 2014-05-14, Hyalella azteca for Survival on 2015-05-05, Hyalella azteca for Survival on 2018-05-21, Hyalella azteca for Survival on 2019-05-30, Hyalella azteca for Growth (wt/surv indiv) on 2019-05-30, Chironomus dilutus for Survival on 2020-06-09, Hyalella azteca for Survival on 2020-06-09, Hyalella azteca for Growth (wt/surv indiv) on 2020-06-09.

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:

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: 801CCPT12 ( Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge ).

Temporal Representation:

The samples were collected between the dates of 2011-05-25 and 2020-06-09.

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 133192, Bifenthrin	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

238727

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Evaluation Guideline:

The evaluation guideline for bifenthrin is the median lethal concentration (LC50) of 0.43 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.43 ug/g is the geometric mean of LC50 values for bifenthrin (Amweg et al., 2005 and Amweg and Weston, 2007).

Guideline Reference:

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2013-05-16 to 2019-05-30

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.


DECISION ID	133189	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

Pollutant:	Pyrethroids
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 3.6 of the Listing Policy. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with sediment toxicity to justify adding that pollutant to the CWA section 303(d) List. Two lines of evidence are available in the administrative record to assess this pollutant. Eight of the eight sediment samples exceed the WARM Pyrethroid guideline. Eight of 10 sediment samples exhibited sediment toxicity. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification for 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. Eight of the eight sediment samples exceed the WARM Pyrethroid guideline, and this sample size is sufficient to determine beneficial use support, with the power and confidence of the Listing Policy. There is associated sediment toxicity data as required by Section 3.6 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:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 133189, Pyrethroids	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

238147

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

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:

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 monitoring site: 801CCPT12 ( Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge ).

Temporal Representation:

The samples were collected between the dates of 2011-05-25 and 2020-06-09.

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 133189, Pyrethroids	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

239414

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

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:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Evaluation Guideline:

The evaluation guideline for the protection of aquatic life from pyrethroids is one toxic unit. Individual pyrethroid concentrations in sediment were normalized to organic carbon content, divided by the respective LC50 and then summed. A sum over over one toxic unit is an exceedance of the evaluation guideline (Amweg et al. 2006).

Guideline Reference:

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Guideline Reference:

Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids

Guideline Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 801CCPT12 (Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge).

Temporal Representation:

Data for this waterbody were collected over the date range 2011-05-25 to 2019-05-30

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.


DECISION ID	133188	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

Pollutant:	Toxicity
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 3.6 of the Listing Policy. Under section 3.6 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. Eight of the 10 sediment samples exceed the WARM Toxicity guideline. Zero of 1 water samples exceed the WARM Toxicity 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. Eight of the 10 sediment samples exceed the WARM Toxicity 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:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 133188, Toxicity	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

238147

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

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:

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 monitoring site: 801CCPT12 ( Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge ).

Temporal Representation:

The samples were collected between the dates of 2011-05-25 and 2020-06-09.

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 133188, Toxicity	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

238158

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 Stream Pollution Trends for Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel) 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: Hyalella azteca for Survival.

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 monitoring site: 801CCPT12 ( Chino Creek (San Antonio Ck) at Euclid/Hwy 83 bridge ).

Temporal Representation:

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

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	99809	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

Pollutant:	Chemical oxygen demand (COD)
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Sources:	A Source Unknown
Expected TMDL Completion Date:	2019
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	While there was no new data considered in the 2016 Listing Cycle, there were questions raised by stakeholders regarding the appropriateness of the water quality objectives applied and it was pointed out that pre-2003 data no longer represents current conditions. The water quality objective used in the 2010 Line of Evidence was 15 mg/L COD and was identified as protecting the WARM beneficial use. It should be noted that the lower segment of the waterbody (Reach 1A) is 30 mg/L. In 2003, the waterbody was split into two segments and Reach 1A COD water quality objective was set to insure that the discharge into Reach 1A of Santa Ana River flows that were diverted through treatment wetlands would not result in exceedances of the Reach 1A objectives. It is not clear in the Region 8 Basin Plan whether the 15 mg/L objective was intended to be protective of a beneficial use or of ambient water quality conditions (anti-degradation). The doubling of the objective to allow the use of treatment wetlands would indicate anti-degradation. It should also be noted that only 8 of the 99 samples would have exceeded the 30 mg/L objective of Reach 1A, an insufficient exceedance rate to justify a Listing. Further, in 2003, a discharge point for the Inland Empire Utilities Agency RP2 sewage treatment plant was eliminated when the plant was decommissioned. The data in the 2010 Line of Evidence (6 samples) show no exceedances of the 15 mg/L objective after the decommission of RP2. While six data points would be insufficient to delist based on Table 4.2 of the Listing Policy, using Section 4.11 of the Listing Policy (Situation-Specific Weight of Evidence) Regional Board staff find that: the lack of certainty regarding whether exceedance of 15 mg/L COD would impair the WARM beneficial use in Chino Creek Reach 1B; whether exceedance of anti-degradation based objectives are appropriately addressed through the 303(d) Listing process; and, most importantly the decommission of the treatment plant and it's discharge point, sufficiently changes the conditions of Chino Creek Reach 1B to make the use of pre-2003 samples inappropriate for Listing determination, are sufficient to warrant a delisting per Section 4.11 of the Listing Policy. State Water Board staff would like to have more recent data that verifies that discharges are no longer occurring and that COD is no longer an issues prior to delisting. Furthermore, the applicable site specific objective is 15 mg/L as iterated in the Basin Plan for this reach.

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

State Board Review of Regional Board Conclusion and Recommendation:	State Water Board staff would like to have more recent data that verifies that discharges are no longer occurring and that COD is no longer an issues prior to delisting. Furthermore, the applicable site specific objective is 15 mg/L as iterated in the Basin Plan for this reach.

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the following changes to the decision: The water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.

Line of Evidence (LOE) for Decision ID 99809, Chemical oxygen demand (COD)	Region 8
Chino Creek Reach 1B (Mill Creek confl to start of concrete lined channel)

LOE ID:

7891

Pollutant:

Chemical oxygen demand (COD)

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:

Of the 99 samples collected 81 exceeded the Basin Plan's Objective

Data Reference: