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Learn about the two types of sewers in your home

Typical Sewer Connection

Bay Area homes have two types of sewers:

1. Storm sewer
  • Collects storm water from street drains and house gutters
  • Leads eventually to the Bay
2. Sanitary sewer
  • Carries wastewater (sewage)
  • Connected to your home's plumbing (toilets, sinks, tubs, laundry)
  • Leads to a sewage treatment plant
Your home's sewer is connected to the sewer main (large pipe often running under the street) via a lateral pipe extending from the home (upper lateral), across the property line (lower lateral), and then into the main.
Remodeled home
If your home was built or remodeled after 1962, local building codes require that your sewer system has a cleanout and a backflow prevention device (also called a sewer relief device).

The cleanout allows you to access the lateral to clear blockages in your sewer line. To get to your cleanout, look for the lid -- a round or square plate labeled "sewer" -- near the property, street, or sidewalk in front of your home. In some cases, a cleanout may be located in the yard near your home or in your backyard, if the sewer main runs behind the house.

In many communities, homeowners are responsible for maintaining the upper lateral that runs under their property. The city or sewer district is responsible for maintaining the lower lateral and the main.

In other communities, homeowners must maintain the entire lateral.

To be sure about your responsibilities, you can call your local sewer or sanitation district, located in the phone book under Government listings for wastewater utility services.

Find out more about Sewer Smart Tips for preventing backflows.