Draft 2008 California 303(d)/305(b) Integrated Report

Supporting Information

Regional Board 4 - Los Angeles Region

Water Body Name:	Dominguez Channel Estuary (unlined portion below Vermont Ave)
Water Body ID:	CAE4051200020050203154519
Water Body Type:	Estuary


DECISION ID	16600

Pollutant:	Sediment 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:	Atmospheric Deposition \| Nonpoint Source \| Surface Runoff \| Urban Runoff/Storm Sewers
Expected TMDL Completion Date:	2021
Impairment from Pollutant or Pollution:	Pollutant

Weight of Evidence:	This pollutant is being considered for placement on the 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. 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 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. Four of seven samples exceed the were deemed either moderately or highly toxic and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Three surface sediment results showed elevated lead and zinc bulk sediment levels. These two pollutants are already included on the 303d list thus a connection exists between the pollutant in sediment and toxicity impacts to the aquatic habitat in the waterbody. 5. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are met.

RWQCB Board Decision / Staff 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.

SWRCB Board Decision / Staff Recommendation:

USEPA Decision:

Lines of Evidence (LOEs) for Decision ID 16600


LOE ID:	28531

Pollutant:	Sediment Toxicity
LOE Subgroup:	Toxicity
Matrix:	Sediment
Fraction:	None

Beneficial Use:	Estuarine Habitat
Aquatic Life Use:	Fish Migration \| Fish Spawning \| Marine Habitat \| Preservation of Rare & Endangered Species \| Wildlife Habitat

Number of Samples:	7
Number of Exceedances:	4

Data and Information Type:	Toxicity testing of sediments
Data Used to Assess Water Quality:	Four of seven sediment samples were deemed either moderately or highly toxic and associated with elevated lead and zinc concentrations in bulk sediment. One sediment toxicity evaluation was performed and results suggested that organophosphate compounds might also be contributing to bulk toxicity.
Data Reference:	Southern California Bight 2003 Regional Marine Monitoring Survey Data

Water Quality Objective/Criterion:	The Basin Plan states that, "[a]ll waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life."
Objective/Criterion Reference:	Water Quality Control Plan Los Angeles Region R4 Basin Plan
	Basin Plan Amendments to the Water Quality Control Plan Los Angeles Region R4 Basin Plan as of 02/02/2009

Evaluation Guideline:	Bay et. al. classifies sediment toxicity based on the following survival percentages: Non toxic if greater than or equal to 80% survival; moderately toxic if between 50 to 80% survival; and highly toxic if less than 50% survival.
Guideline Reference:	Southern California Bight 1998 Regional Monitoring Program. Volume IV.

Spatial Representation:	A total of seven stations were monitored in the Dominguez Channel Estuary which include the following stations: 4206 (Lat: 33.80811, Long: -118.22845), 4270 (Lat: 33.82, Long: -118.24123), 4436 (Lat: 33.80914, Long: -118.22876), 4852 (Lat: 33.80311, Long: -118.22758), 5012 (Lat: 33.8159333333, Long: -118.23618), BRI-04 (Lat: 33.7705322266, Long: -118.250032552), and BRI-05 (Lat: 33.7749674479, Long: -118.244938151).
Temporal Representation:	Composite surface sediment samples were taken on 08/08/2003 for stations 4206, 4270, and 4436, on 09/17/2003 for stations 4852 and 5012, on 07/14/2003 for stations BRI-04 and BRI-05, and on 08/06/03 for station BRI-04.
Environmental Conditions:
QAPP Information:	Data was collected in compliance with the sampling and monitoring procedures detailed in Southern California Bight 2003 Regional Marine Monitoring Survey Quality Assurance Manual.
QAPP Information Reference(s):	Southern California Bight 2003 Regional Marine Monitoring Survey (Bight 03) Quality Assurance Manual


LOE ID:	549

Pollutant:	Sediment Toxicity
LOE Subgroup:	Toxicity
Matrix:	Sediment
Fraction:	None

Beneficial Use:	Estuarine Habitat

Number of Samples:	0
Number of Exceedances:	0

Data and Information Type:	Toxicity testing of sediments
Data Used to Assess Water Quality:	One toxicity sample that showed 61 percent survival which is considered toxic (Anderson et al., 1998).
Data Reference:	Placeholder reference 2006 303(d)

Water Quality Objective/Criterion:	Los Angeles RWQCB Basin Plan: All waters should be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological response in, human, plant, animal, or aquatic life.
Objective/Criterion Reference:	Placeholder reference 2006 303(d)

Evaluation Guideline:	Samples were considered toxic if (1) there was a significant difference in mean organism response between the sample and the control, and (2) the mean organism response in the test, as a percent of the control, was less than the threshold based on the 90th percentile minimum significant difference value.
Guideline Reference:	Placeholder reference 2006 303(d)

Spatial Representation:	One station at H. Ford Bridge (BPTCP station 47010.0).
Temporal Representation:	The sample was collected in 1996.
Environmental Conditions:
QAPP Information:	Bay Protection and Toxic Cleanup Program.
QAPP Information Reference(s):