Well & Septic Instructions and Forms

Minimum standard site plan requirements for most applications at Permit Sonoma. (Planning applications have different site plan requirements.) (Version: 06/25/2024)

Information on owners and contractors of their responsibility to protect stormwater quality during construction and to present recommendations on how to protect stormwater quality. Responsible and proper construction management at the job site is essential for the protection of stormwater quality. (Revised 05/07/2006)

Information on the responsibility to protect stormwater quality during construction and to inform the development community of the State Water Resources Control Board’s General Permit requirements for construction projects disturbing one (1) or more total acres of soil. (Revised 08/26/2005)

Best Management Practices that construction site managers shall implement to keep pollutants from entering the storm drain system or nearby waterways. (Revised 12/10/2009)

A septic tank destruction permit is required whenever a septic tank is to be destroyed. The only exception is if another septic system is being installed under a separate permit. This document provides information and procedures for obtaining a septic tank destruction permit. (Version: 12/09/2019)

This form is used to request a paid service from the Well & Septic Division of Permit Sonoma related to an existing or proposed septic system. A permit application may be required following the requested service. (PDF: 145 kB) (Revised 03/09/2006)

The purpose of this form is to specify the basis for not approving a septic system percolation test. (PDF: 57 kB) (Revised 11/17/2006)

Submittal requirements for Onsite Wastewater Treatment System (OWTS) applications and checklists for OWTS plans and design reports for OWTS applications. (Version 12/19/2019)

This application is used to apply for an Operational Permit (OPR) for Non-Standard Onsite Wastewater Treatment Systems (OWTS) or an OWTS that requires monitoring in accordance with Sonoma County Municipal Code, Section 24-33. It also ensures property owners are aware and understand that Non-Standard OTWS or OWTS that require monitoring are subject to OPR conditions and monitoring requirements. Valid OPRs are transferable to subsequent property owners upon change of property ownership. (Version: 12/13/2021)

Use this form to record and determine the water level drawn and recovered. (PDF: 1.26 MB) (Version 03/02/2020)

Provide information on how to disinfect a well. (Revised 10/18/2005)

Provides guidelines for the proper care of nonstandard septic systems. (Version: 05/10/2023)

Maintenance guidelines for toilets on non-standard sewage disposal systems, how to detect and fix the overuse of water from your toilet. By reducing the amount of wastewater to your septic system, you can help maintain the proper function of your sewage disposal system and save yourself the expense of system replacement. (Revised 04/20/2004)

Lists the process for monitoring an Onsite Wastewater Treatment System (OWTS) utilizing supplemental treatment as required by the Sonoma County Operational Permit Program. The property owner is required to monitor the OWTS utilizing supplemental treatment twice a year during the months of March and October, representing the wet and dry times of the year. (Version: 05/17/2023)

Provides a procedure for purging and adjusting a pressure distribution septic system. (Revised 04/27/2006)

Information for those property owners who are in the Sonoma County monitoring program for Onsite Wastewater Treatment System (OWTS) with supplemental treatment about the availability of a reduced annual operational permit fee. (Version: 05/01/2023)

Provides landscaping guidelines for nonstandard septic systems. (Version: 06/19/2023)

This form is to be used by a septic consultant to request a variance of specific County septic regulations. An administrative variance may be approved by Permit Sonoma’s Well and Septic Division staff when the consultant’s supporting data demonstrates that water quality and public health will not be threatened as a result of such variances. (PDF: 194 kB) (Version 03/01/2021)

The purpose of this form is to identify the potential type(s) of septic system(s) that may be constructed based upon the approved percolation test.  (PDF: 30 kB) (Revised 11/17/2006)

To evaluate septic systems on properties impacted by County declared disasters and for properties providing temporary housing connections to existing septic systems with no county records. (PDF: 489 kB) (Version 04/25/2022)

To determine soil suitability to site and design septic systems. (PDF: 765 kB) (Version 12/01/2019)

To determine soil percolation rates to site and design septic systems. (PDF: 230 kB) (Version 12/01/2019)

To determine the presence and depth of groundwater to site and design septic systems. (PDF: 207 kB) (Version 12/01/2019)

Appendix A of the Onsite Wastewater Treatment Systems (OWTS) Manual with lists of approved experimental and alternative OWTS. (Version 09/15/2019)

This document is to ensure property owners are aware and understand that, under the County Code, non-standard Onsite Wastewater Treatment Systems (OWTS) have additional permitting and monitoring requirements. (PDF: 154 kB) (Version: 12/19/2019)

To provide guidance for septic site evaluations related to County declared disaster rebuilding efforts. (PDF: 169 kB) (Version 12/01/2019)