Return to Wet Weather Percolation and Groundwater Testing page
Revised February 2017
- 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.
- If the closing date falls on a weekend or Monday holiday, the last day to conduct the WWGW test is the previous Friday.
- A complete application with payment must be submitted no later than 12:00 PM one business day prior to the test day.
Example: The test day is Monday. The complete application and payment must be received by 12:00 PM 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.
- 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 via 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 AM to 12 midnight 7 days a week. You will need the WSR number. The number starts with WSR followed by six numbers. (WSR##-####) 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 WSR number and the inspection code. Enter 386, the inspection code for ‘wet weather groundwater test’.
- The qualified septic design professional may cancel a groundwater inspection by calling (707) 565-1694 before 9:00 AM the day of the test. Leave a voice mail message if you can not get through.
- 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.
- All groundwater holes must be clearly marked and numbered or lettered.
- 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 Permit Sonoma Well & Septic staff.