Today we want to shine a spotlight on a specific potential contaminate source in our wellfields – underground storage tanks (USTs) and leaking underground storage tanks (LUSTs). An underground storage tank (UST) is a tank that stores a liquid below the surface of the ground. You often encounter USTs in your daily life at the gas station. However, USTs often eventually leak, and because they are buried, the substance they leak is easily able to contaminate soil and groundwater. We call a UST that has leaked a leaking underground storage tank or a LUST for short. We are especially concerned about USTs and LUSTs in the wellfield, because the chemicals that leak out of a LUST are contaminating the water that will will become Marion County’s drinking water!
We are so concerned about the potential for contaminating groundwater with USTs and LUSTs that current regulations ban all new USTs in the W-1 (one year time-of-travel) and W-5 (five year time of travel) wellfields!
Recently, MCWEC finished analyzing some data about the number of USTs and LUSTs within our wellfields, so we want to share what we learned with you.
Right now, there are about 135 USTs currently in use in all of our wellfields. Historically, there have almost 600 USTs that were once in use in the wellfields, but are now closed or out of service. When we say a UST is closed or out of service, testing has been done to determine whether the UST leaked and contaminated any soil or groundwater around it. It has been emptied and then either pulled from the ground or the tank itself has been filled with something like sand. Riverside wellfield has more USTs than any other wellfield (60 currently in use and over 300 out of service). Ford and Geist wellfield have never had any USTs located within them.
Currently, there are 13 active LUST sites (an active LUST site means that a leak has occurred and environmental consultants are investigating or cleaning it up) with the majority found in the Fall Creek wellfield. Once a leak has been cleaned up, the site is closed and given a designation called “No Further Action” by the Indiana Department of Environmental Management. There have been 155 LUST sites that have been cleaned up in the wellfields with over 60 in the Riverside wellfield alone.
As you can see USTs and LUSTs can contaminate our wellfields, so it is important to make sure UST owners are following all regulations and following best management practices so we can keep our groundwater safe!
Photo by Wisconsin Department of Natural Resources available under the Creative Commons Attribution-NoDervis license
