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Onsite Wastewater Treatment System (OWTS) Application Types Available

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Permit Sonoma offers two main types of OWTS Applications:

  • OTWS Construction Applications
  • OWTS Design Applications

OWTS Construction Application

An OWTS Construction Application is an application filed with Permit Sonoma for the purpose of constructing an OWTS by pursuing either a permit or a vesting certificate.  OWTS Construction Applications may be submitted to perform new, replacement, or repair work in accordance with the OWTS Manual version 7.0 Section 4.8. An OWTS Construction Application would most likely be used to obtain a permit to:

  1. Install a new or replacement septic system.
  2. Replace, repair, or destroy a septic tank, sump tank, or pretreatment unit.
  3. Repair a component of an existing septic system.

OWTS Design Application

An OWTS Design Application is an application filed with Permit Sonoma for the purpose of demonstrating a potential OWTS type and location but not for construction. OWTS Design Applications will not authorize construction and cannot be converted to an OWTS Construction Application. If the intent of the applicant is to receive authorization to perform any work related to a septic system or obtain a vesting certificate for a septic system, then the applicant must submit an OWTS Construction Application. OWTS Design Applications may be submitted to seek approval of a septic design in accordance with the OWTS Manual version 7.0 Sections 4.8.B and 4.8.C only. An OWTS Design Applications would most likely be used to demonstrate:

  1. Lands considered for subdivisions or lot line adjustments can support septic systems.
  2. Code compliant reserve replacement areas.
  3. Properties can support septic systems for real estate transactions or other purposes.

OWTS Application Types Flowchart

See the flowchart below for a graphical representation of the OWTS Application types available and their potential results:

Alternative Description of Flow Chart

This flow chart identifies the different types of OWTS Applications and the path that each application type may take to reach an end result.

If the applicant intends to perform work or get a vesting certificate then the applicant would choose the OWTS Construction Application option.

  • The three available options under OWTS Construction Applications are for New, Replacement, or Repair OWTS work.
    • OWTS Construction Applications for New OWTS work may result in either a permit or a vesting certificate.
    • OWTS Construction Applications for Replacement OWTS work may result in either a permit or a vesting certificate.
    • OWTS Construction Applications for Repair OWTS work may only result in a permit and cannot result in a vesting certificate.

If the applicant does not intend to perform work or get a vesting certificate and only wants a septic design reviewed and approved then the applicant would choose the OWTS Design Application option.

  • The two available options under OWTS Design Applications are for New or Replacement OWTS designs.
    • OWTS Design Applications for New OWTS designs may only result in an approved design and cannot result in a permit nor a vesting certificate.

OWTS Design Applications for Replacement OWTS designs may only result in an approved design and cannot result in a permit nor a vesting certificate.