Oil Tanks and Pipes Tend to Leak

Depending on who you talk to, the possibility that a specific oil storage system is leaking ranges from less than one percent to fifty percent. The limited data collected by Sound Home Inspection Inc. suggests that a realistic number is somewhere in the middle of that range.

Even less is known about the severity of such leaks. At the extreme ends of the spectrum there are leaks which contaminate a few square feet of soil. Then there are the leaks from oil tanks which have contaminated many truckloads full of soil. Translated into the cost of cleanup, the range is from a few hundred dollars to over $100,000.

The fact that an oil tank has leaked and has contaminated the soil usually comes as a surprise to the owner and user of a property. Most oil contamination from underground tanks is not detectable at the surface. Such contamination is often the result of a slow ongoing leak which may not be significant enough to notice a large increase in oil consumption. When contamination is detected, it is usually the result of tank removal, construction work, or soil tests. Some oil leaks are also found as a result of water in the tank, or a dramatic increase in oil consumption as a result of a large hole in the tank. In rare occasions, oil seepage is detected in a basement, drainage system, or the hillside adjacent to the tank.

Some of the factors which contribute to oil tank and oil line leaks are: the age of the tank, the quality of the installation work, the condition of the soil, and luck. Well drained and sandy soil is conducive to long tank life. Wet and clay like soils promote rust and leaking tanks. Finding water inside a tank is a sign of a leaking tank. However, it is not positive proof nor does it indicate how much oil has leaked out of the tank, or for how long.