LACSD Clearwater Program EIR/EIS

The Los Angeles County Sanitation Districts’ Clearwater Program is a facilities planning effort to ensure the continuation of a wastewater collection/treatment effluent management and a wastewater treatment biosolids management system that is protective of public health and the environment. The program contains a Master Facilities Plan affecting 73 cities in Los Angeles County over a 20-40 year planning period.

The LACOSAN ocean outfall project potentially could have resulted in construction and operational impacts to the marine environment. Construction of the project was, therefore, planned to take place via tunneling such that marine-related construction impacts would be limited to where the offshore tunnel risers, seafloor pipelines, and diffusers were located at the bottom of the Pacific Ocean. However, oceanographic processes such as currents and temperature stratification influences the discharge of effluent once the outfall becomes operational. These processes could impact effluent dispersion and consequently water quality, sedimentation patterns, and possibly the benthic (ocean floor) environment.

MBC searched for and compiled current and historical information and data about the project area from published literature, monitoring reports, technical and special study reports, government sources and personal knowledge to assemble a comprehensive data resource for use by all project members. MBC also reviewed historical data trends, DDT/PCB contaminated sediment areas, navigation, benthic habitat, and local fish populations to prepare a constraints analysis for use by project engineers to help evaluate project alternatives early in the design phase. When the project was further defined, MBC assisted with the preparation of the project EIR/EIS by determining potential impacts to the local marine biology and water quality.