Sewer System


Sewer System

Located in Walnut Creek at the junction of Highway 24 and Interstate 680, Collection System Operations’ role is to ensure that over 1,500 miles of underground sewers are able to collect and transport wastewater to the treatment plant safely and efficiently every day.


Collection System Renovation Projects

Project-specific information such as descriptions, maps, and contacts can be found here.


Project Description The Downtown Walnut Creek Sewer Renovation Project replaces sewers primarily along Locust Street in downtown Walnut Creek.

The streets impacted by this work include:


Sewer System Management Plan

The District has prepared a Sewer System Management Plan (SSMP) in accordance with the requirements of the State Water Resources Control Board (SWRCB) Order No. 2006-0003-DWQ, Statewide General Waste Discharge Requirements for Sanitary Sewer Systems.

The goals of the SSMP are to:


Maintenance & Repair

Central San’s Collection System Operations Division (CSO) ensures that over 1,500 miles of underground pipeline (sewers) are able to collect and transport wastewater to the treatment plant effectively. They do this in the following ways.

Maintenance Scheduling System

Central San’s Maintenance Scheduling System is a planned schedule for cleaning of sewer lines that are highly susceptible to root intrusion, grease, and various debris. The frequency of cleaning these sewers is determined by their cleaning history with the goal of preventing sewage overflows.


Service Area & Statistics

Service Area Map

Central San collects and cleans more than 13 billion gallons of wastewater per year for nearly 500,000 residents and more than 15,000 businesses on over 3,000 parcels in central Contra Costa County.