City of Santa Rosa > Departments > Water > Sewer/Wastewater > Sewer Backups/Blocks
You can prevent Sewer Overflows

Sewer overflows and backups can cause health hazards, damage homes and threaten the environment. The most common cause of the overflows is sewer pipes becoming blocked by grease or foreign materials.

Grease usually enters the sewer system through the kitchen sink. Grease is found in items such as meat fats, lard, cooking oil, food scraps and dairy products. The grease sticks to the sides of the pipes on your property and in the streets. Over time, build-up can cause a block in the entire pipe.

Foreign materials also contribute to overflow by entering through unsecured clean-out caps and broken sewer laterals.

More information on overflows may be found on the California Integrated Water Quality System Project (CIWQS) website at: http://www.waterboards.ca.gov/ciwqs/

What this may mean to you is:

  • Raw sewage overflowing in your home or your neighbor’s home;
  • An expensive and unpleasant cleanup;
  • Raw sewage overflowing into streets, yards, parks and creeks;
  • Potential contact with disease-causing bacteria; and
  • An increase in repair and maintenance costs for the City of Santa Rosa, which causes higher sewer rates for customers.

What can you do to help?
The easiest way is to keep grease and foreign material out of the sewer in the first place.

How can you do this?

  • Never pour grease down the sink or toilet.  Place all cooking grease and oil in a sealed container and dispose in the trash.
  • Scrape grease and food scraps off of cooking surfaces and put them into the trash for disposal.
  • Do not put grease down the garbage disposal.  Garbage disposals do not keep grease out of the system, they only shred material into smaller pieces.   Put in sink strainers to collect scraps and place scraps in the trash.
  • Secure all sewer clean-out caps and repair any broken sewer laterals.
  • Call the City of Santa Rosa, Environmental Services Section at (707) 543-3369 if you have any questions.


We have emergency on-call service available 24 hours a day, 7 days a week, 365 days a year.  Our goal is to respond to calls within a 30-minute time-frame, or less when possible.

If a backup or blockage occurs our phone numbers are:

Monday-Friday (excluding holidays) 8am to 5pm: (707) 543-4200

After hours, weekends, holidays:  (707) 543-3805