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. Under the WDRs, the owners of such systems must maintain and implement a Sewer System Management Plan (SSMP) to control and mitigate sewer overflows and make it publicly available.

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 in the following three Sanitary Sewer Systems. 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, including 6,117 miles of gravity sewer and 24 miles of force main. Currently an average wastewater flow rate of nearly 300 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 that is collected and conveyed to the plant by 318 miles of gravity sewer and 13 miles of force main.
• City of Los Angeles Regional Sanitary Sewer System - Approximately five (5) million gallons per day of wastewater is generated which is conveyed to and treated at the County Sanitation Districts' Joint Water Pollution Control Plant in Carson under contractual agreements. This service area consists of 113 miles of gravity sewer and one (1) mile of force main.

In accordance with the State WDRs, the City audits its SSMPs a minimum of once every two years, including a review of their compliance with the WDRs and effectiveness in controlling and responding to sanitary sewer overflows. The last audit was completed in February 2013 which confirmed that the City’s SSMPs are in full compliance and perform exceptionally well. Sewer overflows 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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