Los Angeles Basin Contaminated Sediments Task Force

Summary of Watershed Management & Source Reduction Committee Meeting

on August 26, 1999

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Attendees

Mark Gold, Mitzy Taggart, Heal the Bay
Lauma Jurkevics, California Coastal Commission
Michael Lyons, Xavier Swamikannu, LA Regional Water Quality Control Board
Tony Risko, U.S. Army Corps of Engineers
Bill Depoto, LA County Department of Public Works
Guangyu Wang, Santa Monica Bay Restoration Project
Rick Cameron, Port of Long Beach
Louise Adams, MEC Analytical Systems

LA County Department of Public Works Stormwater Monitoring Report

At the last subcommittee meeting, we indicated that each member would be receiving a copy of the report; however, it turns out that LA County did not have enough hard copies of the report for mass distribution. The County is planning to place the annual report on the web, but it is not available yet.

Bill Depoto presented a summary of LA County’s recently issued annual report. They addressed loading estimates in the report, going back to the 1994-5 data for the Santa Monica Bay watersheds, and back to 1996 for most other watersheds. They compared stormwater concentrations to state standards (e.g., Ocean Plan, Basin Plan, Toxics Rule) to identify pollutants of concern and performed more detailed analyses for the compounds that exceeded standards (17 compounds). They plotted mass emissions for different land uses to develop loadings. The County has completed all of its freshwater toxicity testing. Runoff toxicity seemed to be correlated with the number of prior days with no rainfall (i.e., first storm of the season showed the highest toxicity). Bacterial contamination results were all over the place. Copper and zinc appeared to be responsible for much of the toxicity observed from receiving water studies (did not do TIEs on freshwater samples from storm drains). The observed monitoring results compared favorably with the loading model for Ballona for one storm. A question remains about PAH detection limits; the Regional Board has asked the County to use lower detection limits (already used by Ventura County) on water column samples for future sampling. LA County’s stormwater permit will be up for renewal in 2001, so the subcommittee should help design modifications to the monitoring program during the upcoming year.

CH2M-Hill Ballona Stormwater Sampling

Questions about the upcoming study led us to call Tony Risko, U.S. Army Corps of Engineers, for information on the status of this project. The Corps is considering expanding the sampling to include areas beyond the channels to look at hot spots (but they need approval from Public Works to expand scope, since their money is paying for the study). Hot spots might include transportation sources (e.g., intersections, freeway catch basins), abandoned drilling sites, Oxford Basin. Tony will resend the proposed scope of work to subcommittee members for review and comments by September 1st. The Corps hopes that sampling can begin in September and the raw data may be available by October. The results of this study may guide further monitoring and source control efforts.

1999-2000 Workplan

We have completed most of the tasks identified for Year 2 (Fiscal Year 1998-99), except for Task 2.3. We had assumed that if we could identify a few specific pollutants of concern, it would be useful to research existing BMPs that would target source control for these particular constituents. However, we seem to have widespread pollution from classes of compounds (e.g., trace metals, pesticides) and have not been able to zero in on just a few compounds, so we have not been able to perform this task.

The major task planned for Year 3 (1999-2000) is to complete the source identification and loadings estimates for the watersheds of interest (Ballona, Dominguez Channel, Los Angeles River, San Gabriel River). We can quantify loadings for these watersheds based on Los Angeles County’s monitoring data, but we will need additional work for source identification; the CH2M-Hill study for the Army Corps of Engineers should help us with this.

During Years 3 and 4, we should be able to develop source control measures based on the model and land uses; we also may be able to focus on specific industries as sources of particular pollutants. LA County Department of Public Works must provide a report to the Regional Board on control strategies by July 21, 2000. By Year 4, 23 should be in a position to calculate costs of the implementation strategies. Sediment capture options are being evaluated pretty thoroughly for Ballona Creek; we may need to focus more effort on the Los Angeles River watershed after we see results for Ballona.

Data Gaps

The objective of the subcommittee is to reduce pollutants of concern within the four watersheds of interest, but we have been focusing much of our effort on the Ballona watershed. The subcommittee members believe that this is appropriate, since we should be able to use the answers from Ballona to develop models for the other watersheds.

Data Gap #1 – Review of existing data: we need to see where we are when CH2M-Hill completes its report for the Army Corps of Engineers. It is possible that the Regional Board will be able to integrate some of the existing industrial facilities’ stormwater data to look for sources of specific pollutants of concern, using LA County’s database and ranking SAIC codes vs. pollutant concentrations.

Data Gap #2 – Adequacy of existing monitoring: the subcommittee members should be able to use the CH2M-Hill results to help redesign LA County’s monitoring program (and others) to focus on establishing the link between stormwater pollution and contaminated sediments.

Data Gap#3 – Pinpointing sources of contamination: The results from the CH2M-Hill study should help us decide what further information is needed for this task.

Next Meeting: November 9, 1999 – 1-3 pm, LA Regional Water Quality Control Board


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