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

Supporting Information

Regional Board 4 - Los Angeles Region

Water Body Name:	Arundell Barranca (Ventura County)
Water Body ID:	CAR4031100020110223094904
Water Body Type:	River & Stream


DECISION ID	151135	Region 4
Arundell Barranca (Ventura County)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	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 151135, Benthic Community Effects	Region 4
Arundell Barranca (Ventura County)

LOE ID:

305388

Pollutant:

Benthic-Macroinvertebrate Bioassessments

LOE Subgroup:

Population/Community Degradation

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Benthic macroinvertebrate surveys

Data Used to Assess Water Quality:

Water Board staff assessed data for 407CE0092 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.541468867 to 0.541468867.

Data Reference:

California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 4.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

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

Guideline Reference:

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

Spatial Representation:

Samples were collected from station 407CE0092.

Temporal Representation:

Samples were collected from 4/27/2004 to 4/27/2004.

Environmental Conditions:

QAPP Information:

Data were collected using Surface Water Ambient Monitoring Program protocols

QAPP Information Reference(s):

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

Line of Evidence (LOE) for Decision ID 151135, Benthic Community Effects	Region 4
Arundell Barranca (Ventura County)

LOE ID:

305390

Pollutant:

Benthic-Macroinvertebrate Bioassessments

LOE Subgroup:

Population/Community Degradation

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Benthic macroinvertebrate surveys

Data Used to Assess Water Quality:

Water Board staff assessed data for 407CE0668 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.345330215 to 0.345330215.

Data Reference:

California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 4.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

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

Spatial Representation:

Samples were collected from station 407CE0668.

Temporal Representation:

Samples were collected from 5/22/2007 to 5/22/2007.

Environmental Conditions:

QAPP Information:

Data were collected using Surface Water Ambient Monitoring Program protocols

QAPP Information Reference(s):

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

Line of Evidence (LOE) for Decision ID 151135, Benthic Community Effects	Region 4
Arundell Barranca (Ventura County)

LOE ID:

305389

Pollutant:

Benthic-Macroinvertebrate Bioassessments

LOE Subgroup:

Population/Community Degradation

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Benthic macroinvertebrate surveys

Data Used to Assess Water Quality:

Water Board staff assessed data for 407CE0220 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.635079676 to 0.635079676.

Data Reference:

California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 4.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

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

Spatial Representation:

Samples were collected from station 407CE0220.

Temporal Representation:

Samples were collected from 5/3/2006 to 5/3/2006.

Environmental Conditions:

QAPP Information:

Data were collected using Surface Water Ambient Monitoring Program protocols

QAPP Information Reference(s):

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


DECISION ID	96940	Region 4
Arundell Barranca (Ventura County)

Pollutant:	Indicator Bacteria
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:	2027
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 3.3 of the Listing Policy. Under section 3.3 a single line of evidence is necessary to assess listing status. 7 line of evidence are available in the administrative record to assess this pollutant. Enterococcus single sample: 113 of 227 samples exceeded the objective. geomean: 119 of 161 samples exceeded the objective. Fecal coliform single sample: 46 of 242 samples exceeded the objective. geomean: 48 of 171 samples exceeded the objective. Total coliform single sample: 139 of 242 samples exceeded the objective. geomean: 170 of 171 samples exceeded the objective. Fecal coliform/Total coliform ratio 8 of 242 samples exceeded the objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Samples for enterococcus, fecal coliform and total coliform exceeded the objective in a frequency that exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	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 96940, Indicator Bacteria	Region 4
Arundell Barranca (Ventura County)

LOE ID:

82961

Pollutant:

Total Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

171

Number of Exceedances:

170

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

170 of the 171 samples exceeded the geomean objective for total coliform.

Data Reference:

Data for Bacteria Indicator from Peninsula Beach (Harbor Cove), Ventura Harbor, Ventura Keys, and Arundell Baranca, 2002-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Geometric Mean: The total coliform concentration shall not exceed 1000/100 ml. Basin Plan Region 4. ref1485 California Ocean Plan 2006.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Objective/Criterion Reference:

Water Quality Control Plan Ocean Waters of California. California Ocean Plan 2005. Sacramento, CA: State Water Resources Control Board, California Environmental Protection Agency

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from Arundell Barranca. CAR4031100020110223094904

Temporal Representation:

Samples were collected approximately weekly from January 2003 to July 2005.

Environmental Conditions:

QAPP Information:

Laboratory QA document is provided. The samples were analyzed under the Quality Assurance Program for the City of Buenaventura Wastewater Laboratory.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 96940, Indicator Bacteria	Region 4
Arundell Barranca (Ventura County)

LOE ID:

82962

Pollutant:

Total Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

242

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

8 of the 242 samples exceeded the objective for total coliform when the fecal coliform/total coliform ratio exceeds 0.1.

Data Reference:

Data for Bacteria Indicator from Peninsula Beach (Harbor Cove), Ventura Harbor, Ventura Keys, and Arundell Baranca, 2002-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Total coliform density shall not exceed 1,000 per 100 ml when the fecal coliform/total coliform ratio exceeds 0.1. Basin Plan Region 4. California Ocean Plan 2009.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Objective/Criterion Reference:

Water Quality Control Plan Ocean Waters of California. California Ocean Plan 2005. Sacramento, CA: State Water Resources Control Board, California Environmental Protection Agency

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from Arundell Barranca. CAR4031100020110223094904

Temporal Representation:

Samples were collected approximately weekly from January 2003 to July 2005.

Environmental Conditions:

QAPP Information:

Laboratory QA document is provided. The samples were analyzed under the Quality Assurance Program for the City of Buenaventura Wastewater Laboratory.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 96940, Indicator Bacteria	Region 4
Arundell Barranca (Ventura County)

LOE ID:

82960

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

171

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

48 of the 171 samples exceeded the geomean objective for fecal coliform.

Data Reference:

Data for Bacteria Indicator from Peninsula Beach (Harbor Cove), Ventura Harbor, Ventura Keys, and Arundell Baranca, 2002-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Geometric Mean:The fecal coliform concentration shall not exceed 200/100 ml. Basin Plan Region 4. ref1485 California Ocean Plan 2006.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Objective/Criterion Reference:

Water Quality Control Plan Ocean Waters of California. California Ocean Plan 2005. Sacramento, CA: State Water Resources Control Board, California Environmental Protection Agency

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from Arundell Barranca site K4. CAR4031100020110223094904

Temporal Representation:

Samples were collected approximately weekly from January 2003 to July 2005.

Environmental Conditions:

QAPP Information:

Laboratory QA document is provided. The samples were analyzed under the Quality Assurance Program for the City of Buenaventura Wastewater Laboratory.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 96940, Indicator Bacteria	Region 4
Arundell Barranca (Ventura County)

LOE ID:

82959

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

242

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

46 of the 242 samples exceeded the objective for fecal coliform.

Data Reference:

Data for Bacteria Indicator from Peninsula Beach (Harbor Cove), Ventura Harbor, Ventura Keys, and Arundell Baranca, 2002-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The single sample fecal coliform concentration shall not exceed 400/100 ml. Basin Plan Region 4. ref1485 California Ocean Plan 2006.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Objective/Criterion Reference:

Water Quality Control Plan Ocean Waters of California. California Ocean Plan 2005. Sacramento, CA: State Water Resources Control Board, California Environmental Protection Agency

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from Arundell Barranca. CAR4031100020110223094904

Temporal Representation:

Samples were collected approximately weekly from January 2003 to July 2005.

Environmental Conditions:

QAPP Information:

Laboratory QA document is provided. The samples were analyzed under the Quality Assurance Program for the City of Buenaventura Wastewater Laboratory.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 96940, Indicator Bacteria	Region 4
Arundell Barranca (Ventura County)

LOE ID:

82958

Pollutant:

Enterococcus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

161

Number of Exceedances:

119

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

119 of the 161 samples exceeded the geomean objective for enterococcus.

Data Reference:

Data for Bacteria Indicator from Peninsula Beach (Harbor Cove), Ventura Harbor, Ventura Keys, and Arundell Baranca, 2002-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Geometric Mean: The enterococcus concentration shall not exceed 35/100 ml. Basin Plan Region 4. ref1485 California Ocean Plan 2006.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Objective/Criterion Reference:

Water Quality Control Plan Ocean Waters of California. California Ocean Plan 2005. Sacramento, CA: State Water Resources Control Board, California Environmental Protection Agency

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from Arundell Barranca. CAR4031100020110223094904

Temporal Representation:

Samples were collected approximately weekly from January 2003 to July 2005.

Environmental Conditions:

QAPP Information:

Laboratory QA document is provided. The samples were analyzed under the Quality Assurance Program for the City of Buenaventura Wastewater Laboratory.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 96940, Indicator Bacteria	Region 4
Arundell Barranca (Ventura County)

LOE ID:

82957

Pollutant:

Enterococcus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

227

Number of Exceedances:

113

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

113 of the 227 samples exceeded the objective for enterococcus.

Data Reference:

Data for Bacteria Indicator from Peninsula Beach (Harbor Cove), Ventura Harbor, Ventura Keys, and Arundell Baranca, 2002-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The single sample enterococcus concentration shall not exceed 104/100 ml. Basin Plan Region 4. ref1485 California Ocean Plan 2006.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Objective/Criterion Reference:

Water Quality Control Plan Ocean Waters of California. California Ocean Plan 2005. Sacramento, CA: State Water Resources Control Board, California Environmental Protection Agency

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from Arundell Barranca. CAR4031100020110223094904

Temporal Representation:

Samples were collected approximately weekly from January 2003 to July 2005.

Environmental Conditions:

QAPP Information:

Laboratory QA document is provided. The samples were analyzed under the Quality Assurance Program for the City of Buenaventura Wastewater Laboratory.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 96940, Indicator Bacteria	Region 4
Arundell Barranca (Ventura County)

LOE ID:

82973

Pollutant:

Total Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

242

Number of Exceedances:

139

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

139 of the 242 samples exceeded the objective for total coliform.

Data Reference:

Data for Bacteria Indicator from Peninsula Beach (Harbor Cove), Ventura Harbor, Ventura Keys, and Arundell Baranca, 2002-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The single sample total coliform concentration shall not exceed 10000/100 ml. Basin Plan Region 4. ref1485 California Ocean Plan 2006.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Objective/Criterion Reference:

Water Quality Control Plan Ocean Waters of California. California Ocean Plan 2005. Sacramento, CA: State Water Resources Control Board, California Environmental Protection Agency

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from Arundell Barranca. CAR4031100020110223094904

Temporal Representation:

Samples were collected approximately weekly from January 2003 to July 2005.

Environmental Conditions:

QAPP Information:

Laboratory QA document is provided. The samples were analyzed under the Quality Assurance Program for the City of Buenaventura Wastewater Laboratory.

QAPP Information Reference(s):