Sewage is grossly contaminated (Category 3) water. A backup calls for professional cleanup and a plumber to fix the cause. Here's how that plays out in Sonoma, what to do right now, and how to reach an independent, licensed local provider. Call (628) 336-1777 any time, or use the form on this page.
Sewage backup cleanup in Sonoma: what we see
Sonoma's historic homes often have long-serving sewer laterals under mature trees, and some homes outside city limits use septic. Backups in basements or lower levels of older homes need professional cleanup.
The local picture
House age and sewer laterals. The age of the house is a good guide to the age of the lateral. Sonoma has older and historic homes near the Plaza alongside newer neighborhoods.
Lot, slope and trees. Long laterals, steep runs and big trees all raise the odds of trouble. Sonoma spans the floor of the Sonoma Valley, with wooded hills on either side.
Neighborhoods include the Plaza area, the east and west sides of town, and nearby valley communities. Conditions vary from street to street, so a provider should look at your specific home rather than assume.
What to do right now
- Keep everyone, especially children and pets, out of affected areas.
- Stop using water: no flushing, showers, dishwasher or laundry.
- Don't touch sewage without boots, gloves and eye protection.
- Photograph the damage for insurance.
- Call a plumber for the cause and a restoration provider for cleanup.
Want a local pro to take a look?It's free for homeowners and there's no obligation.
Sonoma checklist
- Locate the cleanout before you need it.
- Find your sewer cleanout so a plumber can reach the lateral quickly.
- Have the lateral camera-inspected if you have big trees and an older home.
- Keep grease and wipes out of drains.
- Check whether your policy has a sewer or water backup endorsement.
Local resources for Sonoma
- Permits: City of Sonoma (Permit Sonoma outside city limits)
- Emergency alerts: SoCoAlert, the County's free notifications
- Sandbags: Sonoma County sandbag locations, updated during weather events
- Contractor licenses: CSLB license check
How a provider handles it
Cleanup involves containment, extraction, removal of porous materials the sewage touched, cleaning and disinfection of hard surfaces, and documented drying before any rebuild. For the full picture, read our complete guide and the deep dive After a flood: cleanup safety. We also have a storm-season article: How to use sandbags.
Before you hire anyone, check the license on the CSLB site. Here's how we vet providers.
Dealing with this right now?Tell us what's happening and we'll connect you with an independent local provider.
More for Sonoma
- Water damage in Sonoma: our full local page
- Sewage backup cleanup service
- Burst pipe water damage in Sonoma
- Crawlspace flooding in Sonoma
- Storm and flood damage in Sonoma
- Appliance and water heater leaks in Sonoma
- Same problem nearby: sewage backups in Glen Ellen & Kenwood, sewage backups in Petaluma, sewage backups in Santa Rosa
- Sewage backup cleanup in every Sonoma County town
Sources
- SoCoAlert sign-up
- Sonoma County sandbag locations
- FEMA Flood Map Service Center
- CDC: flood safety
- CSLB license check
Sources checked October 18, 2026.
Frequently asked questions
Who provides sewer service in Sonoma Valley?
It depends on where you live. Many homes are on a public sewer system and some rural homes use septic. Your bill names your provider.
Does homeowners insurance cover sewage backups?
Often only with a specific water backup endorsement. Check your policy.
Can I clean it myself?
Most sewage backups call for professional cleanup because of contamination. See categories of water.