The following identifies the minimum submittal requirements for various OWTS application types.
Before submitting an OWTS application, be sure you are applying for the correct type!
More Information About Available OWTS Application Types
OWTS Design Applications for New or Replacement OWTS
- Request for service form
- Plan check fee
- Two copies of OWTS site plan
- Two copies of OWTS design report
- Variance request(s), if applicable (variance requests must be submitted as a separate application)
OWTS Construction Applications for New or Replacement OWTS
OWTS Construction Applications for Repairs and New or Replacement Tanks, Pretreatment Units, Interceptor Drains
OWTS Design Requirements: Designs must comply with the provisions of the Sonoma County Code (SCC), Sonoma County Onsite Wastewater Treatment System Regulations and Technical Standards (OWTS Manual) and all relevant laws, ordinances, regulations and conditions of approval. Most systems must be designed by a Qualified Consultant (a civil engineer or an environmental health specialist holding a valid California registration).
OWTS Site Plans: Plans shall be of sufficient clarity to indicate the nature and extent of the work proposed. A valid California seal of professional license and signature is required on all sheets for plans prepared by a Qualified Consultant. Plans shall include and clearly identify the applicable items listed under OWTS Site Plan Requirements section below. Additional information may be required to ensure compliance with SCC, OWTS Manual, or to clarify the work proposed.
OWTS Design Reports: Design reports shall be prepared with sufficient clarity, calculations, and supporting documentation to justify the OWTS design. A valid California seal of professional license and signature is required on the cover sheet of design reports prepared by a Qualified Consultant. Design reports shall include the applicable items listed under the OWTS Design Report section below. Additional information may be required in order to ensure compliance with SCC, OWTS Manual, or to support the plans.
Approval of an OWTS Application shall only constitute compliance with the provisions of the County’s OWTS Manual and shall not mean or imply any other land use entitlement or construction approval.
For more information regarding OWTS applications, please visit or call Permit Sonoma’s Well and Septic customer service cubicle at (707) 565-2849 during regular business hours.