CITY OF LOS ANGELES
DEPARTMENT OF PUBLIC WORKS

Sewer System Management Plan (SSMP)

Overview

On May 2, 2006, the State Water Resources Control Board (SWRCB) adopted the Statewide General Waste Discharge Requirements (WDRs) for publicly owned sanitary sewer systems that are greater than one mile in length and collect and/or convey untreated or partially treated wastewater to a publicly owned treatment facility in California. Under the WDRs, the owners of such systems must develop and implement a Sewer System Management Plan (SSMP) to control and mitigate sewer overflows and make it available to any member of the public upon request in writing.

Los Angeles has one of the largest sewer systems in the world including more than 6,600 miles of sewers serving a population of more than four million. Wastewater generated in the City is treated in one of the three systems listed below. To comply with WDRs, a Sewer System Management Plan was prepared for each:

• Hyperion Sanitary Sewer System - The Hyperion System is by far the largest of the City’s sanitary sewer systems. Currently an average wastewater flow rate of nearly 375 million gallons per day (MGD) is generated in the System. About 60 MGD is treated at upstream Donald C. Tillman and Los-Angeles Glendale Water Reclamation Plants. All other flow in the System and the biosolids from these reclamation plants are treated at the Hyperion Treatment Plant located in Playa Del Rey.
• Terminal Island Water Reclamation Plant Sanitary Sewer System - The plant currently processes an average wastewater flow rate of 16 million gallons per day.
• City of Los Angeles Regional Sanitary Sewer System - A small amount of wastewater generated in the City is conveyed to and treated at the County Sanitation Districts' Joint Water Pollution Control Plant in Carson under contractual agreements.

The SSMPs were approved by the City’s Board of Public Works on February 18, 2009. Subsequently and as required by the State Water Board, in February 2011 the City completed an audit of the SSMPs for compliance with the WDRs and effectiveness in controlling sewer overflows. The SSMPs are in full compliance with the WDRs and remarkably effective. Sewer overflows per miles of sewer in Los Angeles are among the lowest in California and the United States.

The City’s SSMPs may be accessed through the above links. Individual parts and subparts of the SSMP may also be accessed through the links provided in the following Table of Contents.

Sewer System Management Plan

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