Underground storage tanks can pose a significant environmental risk if not identified and properly addressed, but sometimes locating tanks can be a challenge. The locations of some underground storage tanks are known but in many cases only small indicators exist to indicate that a tank is present. This article will provide examples of indicators that can be used to locate an underground storage tank.
Tanks that are actively in use typically have a fill pipe and vent pipe at or above ground surface. Even once a tank is removed, not all contractors remember to remove the vent and fill pipe. If any pipes are identified during a site inspection, open the cover if possible and determine the purpose of the pipe.
Sometimes it’s not so easy to see the fill and vent pipe. They may be painted to blend into the side of a building or may be mounted flush with the ground or pavement surface. The fill and vent pipes may not always be located next to each other.
On sites with paved or concrete areas, look for patches or unpaved areas. These may be indicative of a former tank excavation.
Some tanks have a clear surface expression such as a concrete pad with access ports or manholes. This is most common at gasoline filling stations.
Look in the basement or utility room of all site buildings. Most USTs are connected to a boiler using two or more copper pipes. Look along the basement or utility room walls for a location where copper pipes enter from the exterior of the building, especially near the boiler. Old copper piping may appear green in color. These pipes are evidence of a current or former tank.
When in doubt, call a professional. Specialized tools that can be used to find a tank include metal detectors and ground penetrating radar. Soil borings can be installed in the areas of suspected former tanks. Evaluation of backfill material and surrounding soil can also provide information regarding former tanks.
The first step to removing a tank is locating it!