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Well and Septic Systems

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)

Sonoma County Rebuilding Together

Sonoma County Wildfires

Well, Septic, and Sewer
Rebuilding information related to water wells, septic systems, and sewers in areas affected by the 2017 Sonoma Complex Fire and 2019 Kincade Fire.

  • Published on August 16, 2019

    As of August 15, 2019, the Sonoma County Onsite Wastewater Treatment System (OWTS) Manual version 7.0 is in effect.  Customers are hereby advised that any septic applications will be required to comply with the provisions of the OWTS Manual version 7.0.  Customers are further advised of the following updates to Permit Sonoma’s permitting procedures...

  • Published on August 13, 2019

    The Director of Permit Sonoma hereby adopts the County of Sonoma’s Onsite Wastewater Treatment System (OWTS) Manual, version 7.0, dated August 15, 2019.

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Inspections

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.

Seasonal Testing

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.

Contact Information

Contact Well & Septic by Phone
Address
2550 Ventura Avenue
Santa Rosa, CA 95403
38.465074, -122.723705

Well & Septic Maps

Well & Septic Districts Map

Well and Septic Districts Map

Map of Well & Septic's environmental health districts within Sonoma County.