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Wet Weather Groundwater Testing Guidelines

Revised December 2010
  1. Wet Weather Groundwater (WWGW) tests must be conducted by a qualified septic system design professional. An inspection request must be made by the qualified septic system design professional.
  2. If the closing date falls on a weekend or Monday holiday, the last day to conduct the WWGW test is the previous Friday.
  3. A complete application with payment must be submitted no later than 12 p.m. one business day prior to the test day.

    Example: The test day is Monday. The complete application and payment must be received by 12 p.m. Friday.

    A complete application includes a location map, a site map indicating where to enter the property and the area being tested, and gate codes if applicable.


  4. An inspection request phone call must be received no later than 12 midnight the day before the test day. You must call 565-3551 to request the inspection. This is the phone number for the SELECTRON system. This automated inspection request system is a computer system that allows callers to use a touch tone phone to schedule inspections for the following day. The system is available from 6:00 a.m. to 12 midnight 7 days a week. You will need the SEV number. The number starts with SEV followed by six numbers. (SEV##-####) The number can be found at the top of the invoice and the top of the Request for Service. The SELECTRON system will prompt you to enter the SEV number and the inspection code. Enter 386, the inspection code for ‘wet weather groundwater test’.

  5. The qualified septic design professional may cancel a groundwater inspection by calling 565-1694 before 9 a.m. the day of the test. Leave a voice mail message if you can not get through.
  6. The address must be posted at the site entrance. Please advise us if there are dogs or other hazards that staff should be aware of.
  7. All groundwater holes must be clearly marked and numbered or lettered.

  8. A property which is located within 2,500 feet of a dividing line between groundwater determination zones is considered to be in either of the zones. This determination can be made by PRMD Well & Septic staff.
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Although every effort is made to provide complete and accurate information on this website, users are advised to contact appropriate PRMD staff before making project decisions. This may involve contacting more than one section within PRMD (e.g. Building, Plan Check, Zoning, Well & Septic, etc.), since each section implements specific codes or ordinances which may affect your project.
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Permit and Resource Management Department County of Sonoma