Los Angeles County Department of Public Works Sewer Maintenance Division Collection System

Los Angeles County Sewer Maintenance Districts (Districts) consist of the Marina Sewer Maintenance District (Marina SMD), the Consolidated Sewer Maintenance District (CSMD), and its nine special zones. The Districts serve a population of over 2 million people within Los Angeles County unincorporated areas and 37 cities. The Districts are managed by Los Angeles County Public Works, Sewer Maintenance Division. The collection system consists of approximately 4,600 miles of gravity sewer lines; 104,000 manholes; and 98 pump stations. About 95 percent of flows from these local sewers discharge into the County Sanitation Districts of Los Angeles County facilities for treatment and disposal. A small percentage of the total sewage generated within the Districts is treated at the City of Los Angeles, Las Virgenes Municipal Water Districts, and four small CSMD maintained treatment facilities.