Why is it necessary to abandon a septic system?

Onsite Wastewater Treatment Systems, also known as septic systems, treat domestic sewage/wastewater directly on the site. When septic systems are no longer needed, (such as when a building connects to a public sewer system; a tank or septic system is being replaced; or a building project calls for it, like the demolition of a home), they shall be abandoned properly under permit. Septic tanks that are not properly destroyed present serious potential hazards such as cave-in's or collapses, methane gas explosion hazards, asphyxiation hazards, and entrapment or drowning hazards due to tanks filling with water over time.

How is a septic system abandoned?

Because septic tanks present serious hazards for people, pets, and other animals, the septic tank is the only septic system component that is required to be abandoned under permit. This includes septic tanks, pump or vault tanks, holding tanks, cesspools and seepage pits.

The leach field can remain in the ground as it was built. At times, there are building projects that require a leach field to be removed, but it is not generally a requirement of Environmental Health to remove a leach field.

What is the Septic System Abandonment process?

1. Obtain a Septic Abandonment Permit. Submit a Septic Abandonment Permit, with appropriate fee and required documentation (to include a plot plan showing the tank location in relation to property lines and structures), to Environmental Health for review and approval. Work can commence after the permit is approved and issued. Click here for the Septic Abandonment Permit Application form and click here for the fee schedule.
2. The septic tank shall be pumped dry by a Yolo County registered septage pumper truck. Provide a copy of the pump receipt to Environmental Health. Click here for a list of Yolo County registered septage pumper trucks .
3. If abandoning a septic tank in place (burial method):
   1. Remove tank cover and lids;
   2. Break down the baffle (the wall between the chambers);
   3. The bottom of the tank and at least one side shall be crushed so as to prevent subsurface water collection in the tank.
      *(At times, there are unusual circumstances that may require a tank to be filled with concrete instead of crushed and backfilled or removed (e.g., too close to a structure, etc.).  This could be an approved method of burial as it still eliminates the hazards described above).
4. Schedule an inspection with Environmental Health at least 48 hours in advance.
   • If abandoning a tank in place (burial method), an inspection is required prior to backfill/burial.
   • If removing a tank, an inspection is required prior to pulling the tank from the ground.
5. After a satisfactory inspection, backfill the tank excavation. Fill with clean fill dirt, sand, or concrete. If fill dirt is used, it must be well-tamped to minimize settling.
6. The Septic Abandonment Permit is finalized.