The County has conducted several studies related to the Toxic Pollution Total Maximum Daily Load (TMDL) to better understand the nature of the impairment in Marina del Rey Harbor as well as the physical, chemical and biological processes at work in the harbor. Some of the water quality studies the County has been conducting include:

Partitioning Coefficient Study

A Partitioning Coefficient Study Report, required by the TMDL, was submitted by the County of Los Angeles Department of Public Works on behalf of the County of Los Angeles, the California Department of Transportation, and the Cities of Culver City and Los Angeles to the Los Angeles Regional Water Quality Control Board (Regional Board) in 2011. The study investigated copper partitioning in the sediment, water column, and stormwater in Marina del Rey Harbor.  The study suggested that the sediments were not acting as a source of copper to the water column at that time and that higher levels of copper in the upper portion of the water column could be due to sources such as stormwater and boats.

• Partitioning Coefficient Study Report

Low Detection Level Study

A Low Detection Level Study Report, required by the TMDL, was submitted by the County of Los Angeles Department of Public Works on behalf of the County of Los Angeles, the California Department of Transportation, and the Cities of Culver City and Los Angeles to the Regional Board in 2011. The study evaluated low detection level techniques for PCB and chlordane levels in Marina del Rey Harbor and was conducted in conjunction with the Coordinated Monitoring Plan.

• Low Detection Level Study Report

Sediment Characterization Study

The Marina del Rey Sediment Characterization Study, submitted in 2008, investigated sediment chemistry in the front and back basins as well as the main channel of the Marina del Rey Harbor. The report presents sediment concentrations for TMDL constituents throughout Marina del Rey Harbor. In addition to sediment chemistry analyses, a sediment quality objective assessment, including toxicity and benthic community analysis, was conducted as part of the sediment characterization study.

• Sediment Characterization Study
• Appendix A and B: Core Logs and Core Photographs
• Appendix C: Sediment Chemistry and Grain Size Reports
• Appendix D: Solid Phase Test

Sediment Stressor Identification Study

The County of Los Angeles Department of Public Works, in coordination with the Department of Beaches and Harbors, conducted a sediment stressor identification study for Marina del Rey Harbor in 2016.  The study was designed to identify what is causing toxicity to the benthic community.

• Sediment Stressor Final Report

Site Specific Objective Study

The County of Los Angeles Department of Public Works, in coordination with the Department of Beaches and Harbors, received approval from the Regional Board to conduct a site specific objective study for Marina del Rey Harbor. The study was designed to understand the amount of copper loading that is acceptable within the harbor to keep copper at non-toxic levels to aquatic life.

• Site-Specific Objective Study Work Plan
• Implementation Report for Marina del Rey Harbor Copper Site-Specific Objective
• Appendix A: Marina del Rey Harbor Site-specific Objective Study
• Appendix B: Marina del Rey Harbor Copper Mitigation Measures Implementation Progress Report
• Appendix C: Recalculation of Load Allocation