Out of sight, out of mind. That’s exactly how homeowners with oil-fired heating systems think about the buried tank that holds the heating oil. They could be in for a rude awakening. Most homeowners do not know that they are responsible if their oil tank leaks. If a tank leaks and contaminates the surrounding soil, the cost for the cleanup, which includes excavating around the tank, scooping up the oil-saturated soil, and carting it away by a licensed carter, must be paid by the homeowner. This effort can cost thousands of dollars. If the oil leak contaminates an aquifer or a stream, the cost for cleanup can run into tens of thousands.
Most of the buried tanks used to store home heating oil are steel and have a projected life of about twenty years, although the actual life depends on the extent to which water has been accumulating within the tank and on soil conditions. If the oil tank for the house that you want to purchase is that age or older, you have three options. You can ask the seller to provide you with a certification on the integrity of the tank; you can have the tank tested for leaks at your expense; or as a preventive measure you can replace the tank- the most expensive option.
Some homes have buried oil tanks that are no longer in use because their heating system has been converted from oil to gas. If this is the case, ask the seller if the tank has been properly put out of service. If it hasn’t, it should be; otherwise, safety and environmental problems can develop. In many communities, properly putting a tank out of service is a legal requirement. An abandoned tank that has not been properly prepared will eventually deteriorate because of corrosion resulting in leakage, collapse, or both. Leakage, of course, contaminates the soil.
To put a tank out of service properly, the residual oil or sludge at the bottom of the tank must be pumped out and disposed of, using a licensed carter. The tank should then be removed entirely or filled with an approved filler such as sand. If the soil below the tank is contaminated, it must be removed. The exact abandonment procedure may vary depending on the municipality. Check with your local department of environmental conservation or health department for the approved method.