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Septic Site Evaluations

Permit Sonoma has modified the process and procedures for septic site evaluations (soil profile evaluations/pre-percs, percolation testing, and groundwater determinations).  Septic professionals are expected to abide by the procedures below. Non-compliance with these procedures may result in processing delays or denials of Well and Septic Service (WSR) applications and/or future OWTS Applications.


  1. Account Registration. Ensure you are registered for a Permits Online account.
    Before you can apply for your permit:
    1. Register for a Permits Online account if you do not have one already.
    2. Make note of the email address you use to log into your Permits Online account, and provide it to Permit Sonoma staff in Step 2 below.

    A Permits Online account is needed so you can check the status of your permits, pay permit fees, schedule inspections, etc.

  2. Apply for a septic site evaluation. Ensure a complete septic site evaluation application is submitted electronically to Permit Sonoma. (Note: Paper applications must be submitted electronically.)

  3. Receive confirmation of an accepted application.  After a complete application is submitted and fees have been paid, you will receive notification with the permit number related to the septic site evaluation activity. The permit number will start with “WSR” followed by the two-digit year, a hyphen, and four digits (e.g. WSR12-3456) and will be used to request inspections and track progress.

  4. Request an inspection. Request a virtual inspection to schedule a date and time to conduct the septic site evaluation with Permit Sonoma staff which will perform field work remotely using VuSpex video inspections.

  5. Perform the septic site evaluation.  Septic professionals performing septic site evaluations must comply with all applicable provisions of the county’s OWTS Manual (site evaluation and OWTS design criteria) as well as use and adhere to requirements of the following applicable forms:
    1. WLS-039 Soil Profile Evaluation Form (PDF)
    2. WLS-040 Soil Percolation Test Data Form (PDF)
    3. WLS-041 Wet Weather Ground Water Determination Form (PDF)

    Exceptions to the instructions in the forms include:
    1. Scheduling the field work with staff instead of independently performing the site evaluation work, and
    2. Submitting the completed forms for staff review and approval instead of submitting the forms with a future septic permit application.

  6. Submit applicable forms.  Within 30 days after the septic site evaluation work is completed, septic professionals must submit the applicable completed forms noted above for review and completion of the WSR. Forms can be uploaded electronically through Permits Online using the “View My Records” icon, logging in, and searching for your permit number.

    A complete and approved WSR will be required as part of future OWTS Applications for new or replacement septic systems.  Permit Sonoma will not accept any independent septic site evaluation work that is not related to an approved WSR.