One of the most common misconceptions about oil tank testing is that is done with pressure. In fact, the opposite is done. When a tester performs a tank test he puts your tank under 3 pounds of vaccum and places a microphone in your tank. The Down side is there are many reasons a tank can FAIL a tank test, causing a spill number to be created.
Sometimes the 3 pounds isn’t enough to pull air through holes in the bottom of leaky tanks and other times the tank may fail due to a piping issue. For more information http://barrier.com.bh-10.webhostbox.net/failed-tank-test/ We advise our clients; buyers, sellers and home owners to replace the underground storage tank with an aboveground heating oil tank. Especially when it is an older tank. At least you will have a new tank afterwards.
Another way is to test the soil around the tank. This is called a subsurface investigation. This investigation tests the soil and/or water around your oil tank. It allows you to know whether the soil/water around the tank has been impacted.
In the end, any single wall underground home heating oil tank should be replaced with an above ground oil tank. Even if the tank passes a tank test or subsurface analysis.