Let's have a happy FOG-free Thanksgiving!

No one wants to deal with a clogged pipe during the holidays! Read this article, "A FOG-Free Thanksgiving: Take a Second Helping but Hold the Fats, Oils and Grease" to learn more about the problems with pouring fats, oil, and grease (FOG) down the drain. 

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"Flushable" Does not mean flushable

Cleaning wipes, baby wipes, facial wipes, and paper towels are some of the biggest causes of (or contributors to) sewer back-ups in the County of San Mateo Sewer Districts. That’s right - even if the package says “flushable” or “disposable”, they should NEVER be flushed. They belong in the trash.

Flush only toilet paper, put trash in the trash can. Help prevent costly sewer problems and keep our environment safe from sanitary sewer backups and overflows!

Flush only the "3 P's":
  • Pee
  • Poop
  • Toilet Paper

No Wipes. No Paper Towels.

To report a sewer backup, call: (650) 363-4100 (24hr/day)

Find more information here 

Our Service Districts

County Sewer District map

Public Works provides sewer collection services for residents and businesses to 10 sewer maintenance & sanitation districts within the unincorporated areas of San Mateo County.  Please use the Sewer Districts - Address Locator down below to find out if property falls within San Mateo County-maintained Sewer District's jurisdiction.

See Also:

Burlingame Hills Sewer Maintenance District

Crystal Springs County Sanitation District

Emerald Lake Heights Sewer Maintenance District

Fair Oaks Sewer Maintenance District

About Our Program

The sewer collection service program is primarily funded by the Sewer Service Charges that are levied on properties that receive sewer service from the Districts. The Sewer Service Charge is collected annually on the property tax bill. Sewer Service Charge rates for the ten County Sewer Maintenance and Sanitation Districts are set by the San Mateo County Board of Supervisors and are described in Section 4.32.020 of the Ordinance Code. Public Works personnel maintain the sewer mains in a street or easement and related facilities that comprise the collection system. Ownership and maintenance of sewer laterals -- the sewer line that connects the plumbing of a house or business to the sewer main -- are the property owner's responsibility.  Section 4.24 of the Ordinance Code governs sewer mains and laterals.

The County does not operate sewage treatment facilities. Sewage flows from the collection systems in County districts to sewage treatment plants operated by the South Bayside System Authority, or the cities of Burlingame or San Mateo. The County Sewer/Sanitation Districts pay the plant or city that treats the sewage.
 

Service Rates

Sewer Service Charges are prescribed for each residential unit or residential unit equivalent per connection to each district's sanitary sewerage system, per year or portion thereof.

View Rates and Learn More


Sewer System Management Plan

The Sewer System Management Plan, approved in June 2025, provides guidelines for the management, operation, and maintenance  of wastewater collection systems in order to provide reliable service. Attention is given to minimizing infiltration and inflow, and to minimizing the frequency and impact of sanitary sewer overflows.

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Sewer Districts Master Plan

The master plan for each sewer district provides analysis and recommendations regarding the system and proposes a capital improvement plan (CIP).

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Statewide Reported Sewer Spills

The Interactive Sanitary Sewer System Spill Report allows user to view summary information of spills from public sanitary sewer systems.

Click Here