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Septic Permitting Changes Now in Effect

Published: 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:

  1. Applicants for septic permits will be required to visit with a Permit Technician to submit septic applications.  Permit Sonoma will no longer accept drop off septic applications.  This change is being implemented to provide better customer service to our septic applicants and to facilitate consistent business practices regarding permitting of construction work.
  2. Permit Sonoma has consolidated and simplified the types of septic permit applications customers may submit.  Applications for New OWTS, Replacement OWTS, and Repair OWTS will be accepted in compliance with the newly adopted OWTS Manual.  Applications previously allowed under the retired OWTS Manual version 3.0 (including but not limited to Code Compliant OWTS, Class I OWTS, Class II OWTS, Class III, Abatement Repairs, Voluntary Repairs, Addition Repairs, etc.) will no longer be accepted.
  3. Building permit applications will be reviewed for septic approval in compliance with the newly adopted OWTS Manual.  However, Permit Sonoma must also review building permit applications in compliance with the California Plumbing Code, Appendix H, Sections H 101.6 (which requires no structure be erected on a lot where the structure impairs the usefulness of the 100 percent expansion area) and Section H 101.7 (which requires that a site cannot be developed beyond its capacity to properly absorb sewage effluent).  Therefore, adequate reserve replacement area will be required to be clearly shown and identified on building site plans for building permits that require plan check.

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