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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.

Well and Septic Documents

Onsite Wastewater Treatment System (OWTS) Regulations and Technical Standards Manual (PDF: 12.22 MB)

Water Scarce Areas (Groundwater Availability Areas) (PDF)

Kleinfelder Pilot Study of Groundwater Conditions

Selectron Automated Inspection Request System - Well and Septic (PDF)


Graywater Information

Graywater Brochure (PDF)

Graywater Frequently Asked Questions (FAQs)

Chapter 16 Graywater Systems (PDF)



Policies and Procedures

Frequently Asked Questions (FAQs)

Well and Septic Fees

State Septic Regulations (OWTS Policy)

A Homeowner's Guide to Septic Systems - U.S. EPA (PDF: 1.29 MB)

Wet Weather Percolation and Groundwater Testing

Non Standard Septic Systems: Monitoring Program

2003 Monitoring Program Newsletter (PDF)

2004 Monitoring Program Newsletter (PDF)

2005 Monitoring Program Newsletter (PDF)

2006 Monitoring Program Newsletter (PDF)

2007 Monitoring Program Newsletter (PDF)

2008 Monitoring Program Newsletter (PDF)

2009 Monitoring Program Newsletter (PDF)

2010 Monitoring Program Newsletter (PDF)


Document Accessibility Notice
Some of these documents are saved in Portable Document Format (PDF). We recommend you download Adobe® Reader®, a free software that allows you view and print PDF files.

For accessibility assistance with these documents, please contact Permit Sonoma (PRMD), Sonoma County at (707) 565-1900.
Although every effort is made to provide complete and accurate information on this website, users are advised to contact appropriate Permit Sonoma staff before making project decisions. This may involve contacting more than one section within Permit Sonoma(e.g. Building, Plan Check, Zoning, Well & Septic, etc.) since each section implements specific codes or ordinances which may affect your project.
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Permit and Resource Management Department County of Sonoma