The Well and Septic Division staff reviews all development proposals that will rely on wells or septic systems. They also review permit applications for septic system repair or upgrade. Their focus is on protecting health by ensuring that water wells are properly constructed and septic systems protect surface and ground water quality. Sonoma County's soils are notoriously poor for septic systems, so this is a sometimes challenging mission.

Sanitation Sewer Information
A sanitary sewer system collects and transports waste from indoor plumbing fixtures to treatment plants.

Well, Septic, and Sewer
Rebuilding information related to water wells, septic systems, and sewers in areas affected by the major wildfires in Sonoma County.

Inspections
Inspections are necessary to determine whether well or septic construction work is compliant with code requirements, and that the scope of work is in accordance with the related permits.

Inspection Scheduling
Schedule and find out the results of your inspections in one of 3 ways.

Well & Septic Inspection Codes
Find the 3 digit codes needed to schedule inspections.

Wet Weather Percolation and Groundwater Testing
Septic Systems: To protect groundwater from pollutants from septic systems, the Onsite Wastewater Treatment Systems (OWTS) Manual requires that wet weather groundwater table determinations be conducted under specific conditions.

Dry Weather Well Testing
Water Wells: Sonoma County Code requires dry weather well testing for issuance of building permits for new dwellings located in marginal or scarce water zones.

Graywater is wastewater collected from showers, bathtubs, bathroom sinks, and clothes washing machines. Graywater does not include water from toilets, kitchen sinks, or dishwashers. Graywater can be routed to your landscape to help meet your irrigation needs.