Is there an in-ground oil tank in your yard? You don’t care because you don’t plan on selling anytime soon and you don’t want to know the answer because you’ll be required to clean it up if there is an issue. MISTAKE.
Most tanks were left in place when the owner switched to natural gas or other heating methods. Those tanks, even if they were “empty” still have the dregs of oil in them. Over time, metal rusts and in the end starts to look like Swiss cheese. In this case, the tank had completely drained and found ground water. What would have been a roughly $700 decommissioning became a five-figure project.
Where do you start? If you live in Portland, PortlandMaps has most of the historic oil tank permits online. Enter your address and click on the “historic permits” tab. Keep in mind that it is not the definitive answer. If there is copper piping in the basement floor or a cap in the street it is a pretty compelling sign that there was a tank at some point. The question then becomes whether the tank was above ground or below?
If you know there was a tank on the property DEQ can verify whether or not they have records of decommissioning. Companies, such as Alpha Environmental who did the project above, can do soil samples, tank locates and research involving the tank too. The DEQ also has a resource page for their Heat Oil Tank program.
There’s no doubt that you could be opening a can of worms but the sooner you address it the better the bad is likely to be.