Although sewage tanks are generally buried, over time the chance of the tank or an access lid collapsing increases making it a safety hazard. Also, if a tank is abandoned in a careless manner it could be a health hazard. If the tank is to be abandoned when a replacement system is installed or when a connection is made to a central sewer, check and follow requirements of the design if any. Generally no permit will be necessary to properly abandon a sewage tank; however, you should contact your local health agency before you begin to be sure.

When there are no local requirements or other guidance, you should first have the sewage tank emptied of all sewage waste. This should be done by a professional waste hauling company that disposes of the waste at a permitted land application site or wastewater treatment facility. You have some options from there: 1) you can have the sewage tank crushed in place and then backfill the area; 2) you can have the empty tank completely filled with sand or gravel, remove risers, cover openings and then backfill the area; or 3) you can have the empty tank removed from the property and disposed at a landfill provided the landfill can accept it, and then backfill the area. After backfilling, grade the area to shed water and seed with grass.