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

Supporting Information

Regional Board 4 - Los Angeles Region

Water Body Name: Lindero Creek Reach 1
Water Body ID: CAR4042300019990201144612
Water Body Type: River & Stream
 
DECISION ID
137675
Region 4     
Lindero Creek Reach 1
 
Pollutant: Selenium
Final Listing Decision: Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: List on 303(d) list (TMDL required list)(2018)
Revision Status Revised
Sources: A Source Unknown
Expected TMDL Completion Date: 2019
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for removal from the CWA section 303(d) List under section 4.1 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. The original listing decision was made prior to 2006 and is not recorded in the listing database. The decision is represented by LOE 3901
4. 0 of 4 and 0 of 7 samples exceeded the criteria and this is insufficient to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. A minimum of 28 samples are needed to determine if a beneficial use is fully supported using Table 4.1.
5. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 137675, Selenium
Region 4     
Lindero Creek Reach 1
 
LOE ID: 3901
 
Pollutant: Selenium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.
Data Reference: Placeholder reference pre-2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Unspecified
Objective/Criterion Reference: Placeholder reference pre-2006 303(d)
 
Evaluation Guideline: Unspecified
Guideline Reference: Placeholder reference pre-2006 303(d)
 
Spatial Representation: Unspecified
Temporal Representation: Unspecified
Environmental Conditions: Unspecified
QAPP Information: Unspecified
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 137675, Selenium
Region 4     
Lindero Creek Reach 1
 
LOE ID: 252843
 
Pollutant: Selenium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed LA County MS4 data for Lindero Creek Reach 1 to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Selenium.
Data Reference: WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.
 
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: 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: MCW-CIMP 11 (Lindero Creek downstream of Agoura Road crossing, access on road just before Cornell Way).
Temporal Representation: The samples were collected between the dates of 2018-08-16 and 2019-01-31
Environmental Conditions:
QAPP Information: Municipal Separate Storm Sewer System (MS4)
QAPP Information Reference(s): Municipal Separate Storm Sewer System (MS4)
 
Line of Evidence (LOE) for Decision ID 137675, Selenium
Region 4     
Lindero Creek Reach 1
 
LOE ID: 253006
 
Pollutant: Selenium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 7
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed LA County MS4 data for Lindero Creek Reach 1 to determine beneficial use support and results are as follows: 0 of 7 samples exceeded the water quality threshold for Selenium.
Data Reference: WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.
 
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: 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: MCW-CIMP 11 (Lindero Creek downstream of Agoura Road crossing, access on road just before Cornell Way).
Temporal Representation: The samples were collected between the dates of 2016-10-28 and 2019-01-31
Environmental Conditions:
QAPP Information: Municipal Separate Storm Sewer System (MS4)
QAPP Information Reference(s): Municipal Separate Storm Sewer System (MS4)
 
 
DECISION ID
150295
Region 4     
Lindero Creek Reach 1
 
Pollutant: Indicator Bacteria
Final Listing Decision: Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision: Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)(2018)
Revision Status Revised
Sources: Nonpoint Source
TMDL Name: Malibu Pathogens (47 in part)
TMDL Project Code: 236
Date TMDL Approved by USEPA: 01/10/2006
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for removal on the CWA section 303(d) List under sections 2.2 and section 4.3 of the Listing Policy. Under section 4.3 of the Policy, a minimum of one line of evidence is needed to assess listing status.

Two lines of evidence are available in the administrative record to assess this pollutant.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the CWA section 303(d) List. There is sufficient justification to place it in the Being Addressed portion of the CWA 303(d) List because a TMDL has been completed and approved by RWQCB and USEPA, and is expected to result in attainment of the standard.

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. 76 of 105 samples exceeded the geometric mean for E. coli and 18 of 36 samples exceeded the statistical threshold value for E. coli and these exceed the allowable frequency listed in Table NUMBER of the Listing Policy.
4. The Malibu Creek Watershed Bacteria TMDL was approved by USEPA January 10, 2006.
5. Pursuant to section 4.11 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 removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 150295, Indicator Bacteria
Region 4     
Lindero Creek Reach 1
 
LOE ID: 2263
 
Pollutant: Coliform Bacteria
LOE Subgroup: Pollutant-Water
Matrix: Not Specified
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: Unspecified-- This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion:
Objective/Criterion Reference:
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation:
Temporal Representation:
Environmental Conditions:
QAPP Information: QA Info Missing
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 150295, Indicator Bacteria
Region 4     
Lindero Creek Reach 1
 
LOE ID: 303194
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: STV
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 36
Number of Exceedances: 18
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed LA County MS4 data for Lindero Creek Reach 1 to determine beneficial use support and the results are as follows: 18 of the 36 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.
Data Reference: WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The bacteria water quality objective to protect the REC-1 beneficial use where the salinity is less than 1 parts per thousand 95 percent or more of the time applies a statistical threshold value to E. coli of 320 cfu/100 mL, not to be exceeded by more than 10 percent of samples within a calendar month (ISWEBE 2018).
Objective/Criterion Reference: Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s), station(s): MCW-CIMP 11 (Lindero Creek downstream of Agoura Road crossing, access on road just before Cornell Way).
Temporal Representation: The samples were collected between the days of 2016-07-05 and 2019-06-25 .
Environmental Conditions:
QAPP Information: Municipal Separate Storm Sewer System (MS4)
QAPP Information Reference(s): Municipal Separate Storm Sewer System (MS4)
 
Line of Evidence (LOE) for Decision ID 150295, Indicator Bacteria
Region 4     
Lindero Creek Reach 1
 
LOE ID: 303085
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: GeoMean
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 105
Number of Exceedances: 76
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: Water Board staff assessed LA County MS4 data for Lindero Creek Reach 1 to determine beneficial use support and the results are as follows: 76 of the 105 samples exceeded the geomean water quality threshold for E. coli. This is a six week rolling geomean that is calculated weekly.
Data Reference: WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The bacteria water quality objective to protect the REC-1 beneficial use for waters where the salinity is equal to or less than 1 part per thousand 95 percent or more of the time applies a rolling six-week geometric mean of E. coli, not to exceed 100 cfu/100 mL (ISWEBE 2018).
Objective/Criterion Reference: Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s), station(s): MCW-CIMP 11 (Lindero Creek downstream of Agoura Road crossing, access on road just before Cornell Way).
Temporal Representation: The samples were collected between the days of 2016-07-05 and 2019-06-25 .
Environmental Conditions:
QAPP Information: Municipal Separate Storm Sewer System (MS4)
QAPP Information Reference(s): Municipal Separate Storm Sewer System (MS4)
 
 
DECISION ID
137674
Region 4     
Lindero Creek Reach 1
 
Pollutant: Nitrate/Nitrite (Nitrite + Nitrate as N)
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: 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 137674, Nitrate/Nitrite (Nitrite + Nitrate as N)
Region 4     
Lindero Creek Reach 1
 
LOE ID: 243942
 
Pollutant: Nitrate/Nitrite (Nitrite + Nitrate as N)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 4
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed data from the Los Angeles County MS4 Permit to determine beneficial use support. The results are as follows: 0 out of 4 samples exceed the criterion for Nitrate + Nitrite as N.
Data Reference: WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Water Quality Control Plan for the Los Angeles Region gives a site specific objective for Nitrate + Nitrite as N in Lindero Creek Reach 1 of 10 (mg/L).
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Station MCW-CIMP 11 (34.140114, -118.761589), located in Lindero Creek downstream of Agoura Road crossing, access on road just before Cornell Way.
Temporal Representation: The water samples were taken between 8/16/2018 - 1/31/2019, per the monitoring requirements listed in the Los Angeles County Municipal Separate Storm Sewer Permit.
Environmental Conditions:
QAPP Information: The work was performed in accordance with the provisions of the Los Angeles Municipal Separate Storm Sewer System quality control and quality assurance procedures listed in coordinated integrated monitoring plan.
QAPP Information Reference(s): Municipal Separate Storm Sewer System (MS4)
 
 
DECISION ID
149616
Region 4     
Lindero Creek Reach 1
 
Pollutant: Nitrogen, Nitrate
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 149616, Nitrogen, Nitrate
Region 4     
Lindero Creek Reach 1
 
LOE ID: 302530
 
Pollutant: Nitrogen, Nitrate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 5
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed LA County MS4 data for Lindero Creek Reach 1 to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Nitrate as N.
Data Reference: WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Water Quality Control Plan for the Los Angeles Region (page 3-34) states that: Waters shall not exceed 10 mg/L as nitrate-nitrogen (NO3-N).
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: MCW-CIMP 11 (Lindero Creek downstream of Agoura Road crossing, access on road just before Cornell Way).
Temporal Representation: The samples were collected between the dates of 2016-10-28 and 2019-01-12
Environmental Conditions:
QAPP Information: Municipal Separate Storm Sewer System (MS4)
QAPP Information Reference(s): Municipal Separate Storm Sewer System (MS4)
 
Line of Evidence (LOE) for Decision ID 149616, Nitrogen, Nitrate
Region 4     
Lindero Creek Reach 1
 
LOE ID: 302524
 
Pollutant: Nitrogen, Nitrate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed LA County MS4 data for Lindero Creek Reach 1 to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Nitrate as N.
Data Reference: WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Water Quality Control Plan for the Los Angeles Region (page 3-34) states that: Waters shall not exceed 10 mg/L as nitrate-nitrogen (NO3-N).
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: MCW-CIMP 11 (Lindero Creek downstream of Agoura Road crossing, access on road just before Cornell Way).
Temporal Representation: The samples were collected between the dates of 2019-01-31 and 2019-01-31
Environmental Conditions:
QAPP Information: Municipal Separate Storm Sewer System (MS4)
QAPP Information Reference(s): Municipal Separate Storm Sewer System (MS4)
 
Line of Evidence (LOE) for Decision ID 149616, Nitrogen, Nitrate
Region 4     
Lindero Creek Reach 1
 
LOE ID: 302500
 
Pollutant: Nitrogen, Nitrate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed LA County MS4 data for Lindero Creek Reach 1 to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Nitrate as N.
Data Reference: WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Water Quality Control Plan for the Los Angeles Region (page 3-34) states that: Waters shall not exceed 10 mg/L as nitrate-nitrogen (NO3-N).
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: MCW-CIMP 11 (Lindero Creek downstream of Agoura Road crossing, access on road just before Cornell Way).
Temporal Representation: The samples were collected between the dates of 2019-01-05 and 2019-01-05
Environmental Conditions:
QAPP Information: Municipal Separate Storm Sewer System (MS4)
QAPP Information Reference(s): Municipal Separate Storm Sewer System (MS4)
 
 
DECISION ID
137676
Region 4     
Lindero Creek Reach 1
 
Pollutant: Turbidity
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 137676, Turbidity
Region 4     
Lindero Creek Reach 1
 
LOE ID: 252831
 
Pollutant: Turbidity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 2
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed LA County MS4 data for Lindero Creek Reach 1 to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Turbidity.
Data Reference: WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Water Quality Control Plan for the Los Angeles Region states that: Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: Turbidities of 40 NTU or greater can cause a reduced foraging efficiency and a shift in prey selection in piscivorous fish (largemouth bass) due to interference with their ability to find prey (Shoup, D.E. and Wahl D.H., 2009).
Guideline Reference: The Effects of Turbidity on Prey Selection by Piscivorous Largemouth Bass
 
Spatial Representation: The samples were collected at 1 monitoring site: MCW-CIMP 11 (Lindero Creek downstream of Agoura Road crossing, access on road just before Cornell Way).
Temporal Representation: The samples were collected between the dates of 2019-01-05 and 2019-01-31
Environmental Conditions:
QAPP Information: Municipal Separate Storm Sewer System (MS4)
QAPP Information Reference(s): Municipal Separate Storm Sewer System (MS4)
 
Line of Evidence (LOE) for Decision ID 137676, Turbidity
Region 4     
Lindero Creek Reach 1
 
LOE ID: 252873
 
Pollutant: Turbidity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 6
Number of Exceedances: 2
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed LA County MS4 data for Lindero Creek Reach 1 to determine beneficial use support and results are as follows: 2 of 6 samples exceeded the water quality threshold for Turbidity.
Data Reference: WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Water Quality Control Plan for the Los Angeles Region states that: Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses.
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: Turbidities of 40 NTU or greater can cause a reduced foraging efficiency and a shift in prey selection in piscivorous fish (largemouth bass) due to interference with their ability to find prey (Shoup, D.E. and Wahl D.H., 2009).
Guideline Reference: The Effects of Turbidity on Prey Selection by Piscivorous Largemouth Bass
 
Spatial Representation: The samples were collected at 1 monitoring site: MCW-CIMP 11 (Lindero Creek downstream of Agoura Road crossing, access on road just before Cornell Way).
Temporal Representation: The samples were collected between the dates of 2016-08-04 and 2019-01-12
Environmental Conditions:
QAPP Information: Municipal Separate Storm Sewer System (MS4)
QAPP Information Reference(s): Municipal Separate Storm Sewer System (MS4)
 
 
DECISION ID
77467
Region 4     
Lindero Creek Reach 1
 
Pollutant: Benthic Community Effects
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: 2021
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: Regional Board Conclusion:
This pollutant is being considered for the section 303(d) list under section 3.9 of the Listing Policy. Under section 3.9, waters are listed when a bioassessment shows diminished numbers of species or other metrics (compared to a reference site) and it is associated with another pollutant.

Four lines of evidence are available in the administrative record to assess this pollutant. Benthic macroinvertebrates as measured by Southern California IBI (Index of Biological Integrity) in Lindero Creek Reach 1 were very poor in the spring and poor in the fall of 2005 indicating impairment of benthic community structure.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification to place the 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. There is at least one bioassessment sample (Index of Biological Integrity score) to satisfy Section 3.9
4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.

State Board Review and Conclusion:
State Water Board staff used a situation-specific weight of evidence approach to evaluate the Los Angeles Water Board benthic macroinvertebrate ¿bioassessment listing. State Water Board staff determined that it is necessary to include these listings because additional data analyses and multiple line of evidence show that benthic macroinvertebrate populations are impacted by a wide range of stressors. Using this approach staff followed a three-step process for evaluation of all available water quality data including the chemistry and bioassessment data. In the first step, staff reviewed the Los Angeles Water Board data evaluation for bioassessment listing. In the second step, staff reviewed all other available bioassessment data because State Water Board staff learned that some data had not been considered for this listing decision by the Regional Water Board. In step 3 staff reviewed the chemistry water quality data available for total nitrogen and total phosphorus to determine the water quality condition in this water body segment.

In step 1 and 2, State Water Board staff evaluated the bioassessment data using the Southern California index of biological integrity (IBI). Staff reviewed the line of evidence prepared by the Los Angeles Water Board and additional bioassessment data. Benthic macroinvertebrate as measured by Southern California IBI in Lindero Creek Reach 1 were poor in years 2005 through 2008 indicating impairment of benthic community structure.

In step 3, the chemistry data for total nitrogen and total phosphorus were evaluated by State Water Board staff. Data for selenium, invasive species, trash, coliform bacteria, scum/foam-unnatural, and algae were evaluated in a previous listing cycle. Selenium, invasive species, trash, coliform bacteria, scum/foam-unnatural, and algae showed impairment to the warm freshwater habitat, non-contact recreation, and water contact recreation and it resulted in listing this water body in 1996. In this step State Water Board staff evaluated the most recent available data for total nitrogen and total phosphorus. The data for total nitrogen show exceedances of the water quality objective. The data for total phosphorus show exceedances of the water quality objective. The weight of evidence of the data and information indicate that the beneficial use of the water is not supported.

The water quality chemistry and bioassessment data provide a substantial basis that benthic macroinvertebrate populations are impacted by a wide range of anthropogenic stressors. Based on the available data and information, staff recommend to list for benthic macroinvertebrate-bioassessment.
 
Regional Board Decision Recommendation: This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.
 
State Board Review of Regional Board Conclusion and Recommendation: The water quality chemistry and bioassessment data provide a substantial basis that benthic macroinvertebrate populations are impacted by a wide range of anthropogenic stressors. Based on the available data and information, staff recommend to list for benthic macroinvertebrate-bioassessment.
 
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 77467, Benthic Community Effects
Region 4     
Lindero Creek Reach 1
 
LOE ID: 28711
 
Pollutant: Benthic-Macroinvertebrate Bioassessments
LOE Subgroup: Population/Community Degradation
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Wildlife Habitat
 
Number of Samples: 3
Number of Exceedances: 1
 
Data and Information Type: Benthic macroinvertebrate surveys
Data Used to Assess Water Quality: A total of one of three sites showed an increase in density of mud snails over the three years of sampling (2006, 2007, 2008) and two of four sites sampled showed medium or high densities of mud snail in 2008.
Data Reference: New Zealand Mudsnail Surveys July 2006, July 2007 and October 2008 Santa Monica Mountains. Santa Monica Bay Restoration Commission / Santa Monica Baykeeper.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Basin Plan states that: "All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in, human, plant or animal, or aquatic life. Compliance with this objective will be determined by use of indicator organisms, analysis of species diversity, population density, growth anomalies, bioassays of appropriate duration or other appropriate methods as specified by the State or Regional Board.¿
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: Presence of high densities and increasing densities. While quantitative and predictive research continues, due to its ability to attain extremely high densities, the impacts of the mudsnails on aquatic ecosystems where it occurs in the western U.S. are large and include: decreased densities of native macroinvertebrates and reduced food resources; decreased whole-stream algal production; poor food source in that mudsnails are much more difficult to digest, with their hard shells and operculum than are the thin-shelled, native pulmonate snails that do not have opercula or than soft-bodied, aquatic insect larvae.
Guideline Reference: The New Zealand Mudsnail Invades the Western United States. Aquatic Nuisance Species Digest Volume 4 No. 4.
 
Spatial Representation: Four sites were sampled in the following locations in Lindero Creek Reach 1: Lake Lindero Dr. field behind TJ Max; Lake Lindero Dr. spillway; Agoura Rd. culvert; outlet into Medea Creek east of Kanan Rd.
Temporal Representation: Three sites (Lake Lindero, Lake Lindero Dr., Outlet into Medea Creek) were sampled in July of 2006, July of 2007 and October of 2008. The Agoura Rd. site was sampled July of 2007 and October of 2008.
Environmental Conditions:
QAPP Information: Data was collected as detailed in the Santa Monica Bay Restoration Commission and Santa Monica Baykeeper New Zealand Mudsnail Surveys.
QAPP Information Reference(s): New Zealand Mudsnail Surveys July 2006, July 2007 and October 2008 Santa Monica Mountains. Santa Monica Bay Restoration Commission / Santa Monica Baykeeper.
 
Line of Evidence (LOE) for Decision ID 77467, Benthic Community Effects
Region 4     
Lindero Creek Reach 1
 
LOE ID: 30177
 
Pollutant: Benthic-Macroinvertebrate Bioassessments
LOE Subgroup: Population/Community Degradation
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Wildlife Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: Benthic macroinvertebrate surveys
Data Used to Assess Water Quality: The IBI scores at this sites ranked in the ¿very poor¿ range (12) in the spring and ¿poor¿ (17) in the fall.
Data Reference: Malibu Watershed 2005 Bioassessment Monitoring Report. (2005) The Malibu Creek Watershed Monitoring Program City of Calabasas, Environmental Services Division. Submitted by: Aquatic Bioassay and Consulting Laboratories.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Basin Plan states that: "All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in, human, plant or animal, or aquatic life. Compliance with this objective will be determined by use of indicator organisms, analysis of species diversity, population density, growth anomalies, bioassays of appropriate duration or other appropriate methods as specified by the State or Regional Board.¿
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: The IBI is a multi-metric assessment that employs biological metrics that respond to a habitat or water quality impairment. Each of the biological metrics measured at a site are converted to an IBI score then summed. These cumulative scores are then ranked as very good (80-100), good (60-79), fair (40-49), poor (20-39) and very poor (0-19) habitat conditions. Sites with scores below 39 are considered to have impaired conditions.
Guideline Reference: A Quantitative Tool for Assessing the Integrity of Southern Coastal California Streams. Appendix 7-B Environmental Management Vol. 35, No. 4, pp. 493-504.
 
Spatial Representation: One site in Lindero Canyon Creek was sampled, LIN1 at 34° 09.262' N 118° 47.481' W.
Temporal Representation: Sites were sampled in Spring and Fall of 2005
Environmental Conditions: Benthic macroinvertebrate populations and IBI scores may also be affected by a wide range of anthropogenic stressors.
QAPP Information: Data was collected in compliance with California Stream Bioassessment Procedure.
QAPP Information Reference(s): California Stream Bioassessment Procedure (Protocol Brief for Biological and Physical/Habitat Assessment in Wadeable Streams) California Department of Fish and Game Water Pollution Control Laboratory Aquatic Bioassessment Laboratory Revision Date - December, 2003
 
 
DECISION ID
76678
Region 4     
Lindero Creek Reach 1
 
Pollutant: Invasive Species
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: 2021
Impairment from Pollutant or Pollution: Pollution
 
Regional Board Conclusion: This pollutant is being considered for placement in Category 4c as impaired by pollution.under section 3.10 of the Listing Policy. Under section 3.10, waters are listed when a declining trend in water quality is substantiated.

Two lines of evidence are available in the administrative record to assess this pollutant. One of 3 sites showed an increase in density of mud snails over the three years of sampling (2006, 2007, 2008) and 2 out of 4 sites sampled showed medium or high densities of mud snail in 2008.

At high numbers, mud snails can completely cover a stream bed and damage local stream ecosystems. The colonies outcompete native aquatic invertebrates that the watershed¿s fish and amphibians rely on for food, disrupting the entire food web.

Benthic macroinvertebrates as measured by Southern California IBI (index of biological integrity) in Lindero Creek were poor or very poor in 2005 indicating impairment of benthic community structure.

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 in Category 4c as impaired by pollution..

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Data was collected over a three years time frame and a baseline condition of zero abundance of the invasive species was used.
3. One of three sites showed an increase in density of mud snails over a three years of sampling and two of four sites sampled showed medium or high densities of mud snail in 2008.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are met.
 
Regional Board Decision Recommendation: This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
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 76678, Invasive Species
Region 4     
Lindero Creek Reach 1
 
LOE ID: 30177
 
Pollutant: Benthic-Macroinvertebrate Bioassessments
LOE Subgroup: Population/Community Degradation
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Wildlife Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: Benthic macroinvertebrate surveys
Data Used to Assess Water Quality: The IBI scores at this sites ranked in the ¿very poor¿ range (12) in the spring and ¿poor¿ (17) in the fall.
Data Reference: Malibu Watershed 2005 Bioassessment Monitoring Report. (2005) The Malibu Creek Watershed Monitoring Program City of Calabasas, Environmental Services Division. Submitted by: Aquatic Bioassay and Consulting Laboratories.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Basin Plan states that: "All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in, human, plant or animal, or aquatic life. Compliance with this objective will be determined by use of indicator organisms, analysis of species diversity, population density, growth anomalies, bioassays of appropriate duration or other appropriate methods as specified by the State or Regional Board.¿
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: The IBI is a multi-metric assessment that employs biological metrics that respond to a habitat or water quality impairment. Each of the biological metrics measured at a site are converted to an IBI score then summed. These cumulative scores are then ranked as very good (80-100), good (60-79), fair (40-49), poor (20-39) and very poor (0-19) habitat conditions. Sites with scores below 39 are considered to have impaired conditions.
Guideline Reference: A Quantitative Tool for Assessing the Integrity of Southern Coastal California Streams. Appendix 7-B Environmental Management Vol. 35, No. 4, pp. 493-504.
 
Spatial Representation: One site in Lindero Canyon Creek was sampled, LIN1 at 34° 09.262' N 118° 47.481' W.
Temporal Representation: Sites were sampled in Spring and Fall of 2005
Environmental Conditions: Benthic macroinvertebrate populations and IBI scores may also be affected by a wide range of anthropogenic stressors.
QAPP Information: Data was collected in compliance with California Stream Bioassessment Procedure.
QAPP Information Reference(s): California Stream Bioassessment Procedure (Protocol Brief for Biological and Physical/Habitat Assessment in Wadeable Streams) California Department of Fish and Game Water Pollution Control Laboratory Aquatic Bioassessment Laboratory Revision Date - December, 2003
 
Line of Evidence (LOE) for Decision ID 76678, Invasive Species
Region 4     
Lindero Creek Reach 1
 
LOE ID: 28711
 
Pollutant: Benthic-Macroinvertebrate Bioassessments
LOE Subgroup: Population/Community Degradation
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Wildlife Habitat
 
Number of Samples: 3
Number of Exceedances: 1
 
Data and Information Type: Benthic macroinvertebrate surveys
Data Used to Assess Water Quality: A total of one of three sites showed an increase in density of mud snails over the three years of sampling (2006, 2007, 2008) and two of four sites sampled showed medium or high densities of mud snail in 2008.
Data Reference: New Zealand Mudsnail Surveys July 2006, July 2007 and October 2008 Santa Monica Mountains. Santa Monica Bay Restoration Commission / Santa Monica Baykeeper.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Basin Plan states that: "All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in, human, plant or animal, or aquatic life. Compliance with this objective will be determined by use of indicator organisms, analysis of species diversity, population density, growth anomalies, bioassays of appropriate duration or other appropriate methods as specified by the State or Regional Board.¿
Objective/Criterion Reference: Water Quality Control Plan Los Angeles Region R4 Basin Plan
 
Evaluation Guideline: Presence of high densities and increasing densities. While quantitative and predictive research continues, due to its ability to attain extremely high densities, the impacts of the mudsnails on aquatic ecosystems where it occurs in the western U.S. are large and include: decreased densities of native macroinvertebrates and reduced food resources; decreased whole-stream algal production; poor food source in that mudsnails are much more difficult to digest, with their hard shells and operculum than are the thin-shelled, native pulmonate snails that do not have opercula or than soft-bodied, aquatic insect larvae.
Guideline Reference: The New Zealand Mudsnail Invades the Western United States. Aquatic Nuisance Species Digest Volume 4 No. 4.
 
Spatial Representation: Four sites were sampled in the following locations in Lindero Creek Reach 1: Lake Lindero Dr. field behind TJ Max; Lake Lindero Dr. spillway; Agoura Rd. culvert; outlet into Medea Creek east of Kanan Rd.
Temporal Representation: Three sites (Lake Lindero, Lake Lindero Dr., Outlet into Medea Creek) were sampled in July of 2006, July of 2007 and October of 2008. The Agoura Rd. site was sampled July of 2007 and October of 2008.
Environmental Conditions:
QAPP Information: Data was collected as detailed in the Santa Monica Bay Restoration Commission and Santa Monica Baykeeper New Zealand Mudsnail Surveys.
QAPP Information Reference(s): New Zealand Mudsnail Surveys July 2006, July 2007 and October 2008 Santa Monica Mountains. Santa Monica Bay Restoration Commission / Santa Monica Baykeeper.
 
 
DECISION ID
76386
Region 4     
Lindero Creek Reach 1
 
Pollutant: Algae
Final Listing Decision: List on 303(d) list (being addressed by USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision: List on 303(d) list (being addressed by USEPA approved TMDL)(2016)
Revision Status Original
Sources: Agriculture-animal | Atmospheric Deposition | Golf course activities | Groundwater Loadings | Irrigated Crop Production | Major Municipal Point Source-dry and/or wet weather discharge | Onsite Wastewater Systems (Septic Tanks) | Urban Runoff/Storm Sewers
TMDL Name: Malibu Creek Nutrients (50)
TMDL Project Code: 239
Date TMDL Approved by USEPA: 03/21/2003
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for removal on the section 303(d) list under sections 2.2 of the Listing Policy. Under 2.2 of the Policy, a minimum of one line of evidence is needed to assess listing status.

Two lines of evidence are available in the administrative record to assess this pollutant.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the section 303(d) list. There is sufficient justification to place it in the Being Addressed portion of the 303(d) list because a TMDL has been established by USEPA, and is expected to result in attainment of the standard.
 
Regional Board Decision Recommendation: This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
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 76386, Algae
Region 4     
Lindero Creek Reach 1
 
LOE ID: 3899
 
Pollutant: Algae
LOE Subgroup: Pollutant-Nuisance
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Non-Contact Recreation
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.
Data Reference: Placeholder reference pre-2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion:
Objective/Criterion Reference:
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Unspecified
Temporal Representation: Unspecified
Environmental Conditions: Unspecified
QAPP Information: Unspecified
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 76386, Algae
Region 4     
Lindero Creek Reach 1
 
LOE ID: 28620
 
Pollutant: Algae
LOE Subgroup: Narrative Description Data
Matrix: Not Specified
Fraction: None
 
Beneficial Use: Non-Contact Recreation
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: A TMDL has been established for this water segment-pollutant combination. The Malibu Creek Watershed Nutrient TMDL was established by USEPA on March 21, 2003.
Data Reference: Staff report, appendix, and letter to SWRCB and Los Angeles RWQCB establishing a TMDL for Nutrients in the Malibu Creek Watershed.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion:
Objective/Criterion Reference:
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation:
Temporal Representation:
Environmental Conditions:
QAPP Information: QA information unavailable.
QAPP Information Reference(s):
 
 
DECISION ID
76440
Region 4     
Lindero Creek Reach 1
 
Pollutant: Scum/Foam-unnatural
Final Listing Decision: List on 303(d) list (being addressed by USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision: List on 303(d) list (being addressed by USEPA approved TMDL)(2016)
Revision Status Original
Sources: Agriculture-animal | Atmospheric Deposition | Golf course activities | Groundwater Loadings | Irrigated Crop Production | Major Municipal Point Source-dry and/or wet weather discharge | Onsite Wastewater Systems (Septic Tanks) | Urban Runoff/Storm Sewers
TMDL Name: Malibu Creek Nutrients (50)
TMDL Project Code: 239
Date TMDL Approved by USEPA: 03/21/2003
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for removal on the section 303(d) list under sections 2.2 of the Listing Policy. Under 2.2 of the Policy, a minimum of one line of evidence is needed to assess listing status.

Two lines of evidence are available in the administrative record to assess this pollutant.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the section 303(d) list. There is sufficient justification to place it in the Being Addressed portion of the 303(d) list because a TMDL has been established by USEPA, and is expected to result in attainment of the standard.
 
Regional Board Decision Recommendation: This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
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 76440, Scum/Foam-unnatural
Region 4     
Lindero Creek Reach 1
 
LOE ID: 28622
 
Pollutant: Scum/Foam-unnatural
LOE Subgroup: Narrative Description Data
Matrix: Not Specified
Fraction: None
 
Beneficial Use: Non-Contact Recreation
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: A TMDL has been established for this water segment-pollutant combination. The Malibu Creek Watershed Nutrient TMDL was established by USEPA on March 21, 2003.
Data Reference: Staff report, appendix, and letter to SWRCB and Los Angeles RWQCB establishing a TMDL for Nutrients in the Malibu Creek Watershed.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion:
Objective/Criterion Reference:
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation:
Temporal Representation:
Environmental Conditions:
QAPP Information: QA information unavailable.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 76440, Scum/Foam-unnatural
Region 4     
Lindero Creek Reach 1
 
LOE ID: 3900
 
Pollutant: Scum/Foam-unnatural
LOE Subgroup: Pollutant-Nuisance
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Non-Contact Recreation
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.
Data Reference: Placeholder reference pre-2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion:
Objective/Criterion Reference:
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Unspecified
Temporal Representation: Unspecified
Environmental Conditions: Unspecified
QAPP Information: Unspecified
QAPP Information Reference(s):
 
 
DECISION ID
69423
Region 4     
Lindero Creek Reach 1
 
Pollutant: Trash
Final Listing Decision: List on 303(d) list (being addressed by USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision: List on 303(d) list (being addressed by USEPA approved TMDL)(2016)
Revision Status Original
Sources: A Source Unknown
TMDL Name: Malibu Creek Watershed Trash (63)
TMDL Project Code: 719
Date TMDL Approved by USEPA: 05/30/2008
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: 303(d) listing decisions made prior to 2006 were not held in an assessment database.

There is sufficient justification to place this waterbody/pollutant in the Being Addressed portion of the CWA 303(d) List because a TMDL has been completed and approved by USEPA, and is expected to result in attainment of the standard.

This conclusion is based on the staff findings that:
1. The Malibu Creek Trash TMDL was approved by USEPA on 05/28/2008.
.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
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 69423, Trash
Region 4     
Lindero Creek Reach 1
 
LOE ID: 3902
 
Pollutant: Trash
LOE Subgroup: Visual
Matrix: Not Specified
Fraction: Not Recorded
 
Beneficial Use: Non-Contact Recreation
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.
Data Reference: Placeholder reference pre-2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Unspecified
Objective/Criterion Reference: Placeholder reference pre-2006 303(d)
 
Evaluation Guideline: Unspecified
Guideline Reference: Placeholder reference pre-2006 303(d)
 
Spatial Representation: Unspecified
Temporal Representation: Unspecified
Environmental Conditions: Unspecified
QAPP Information: Unspecified
QAPP Information Reference(s):