Buried Oil Tanks
Up to 30% of all underground residential oil tanks leak.
Air that replaces the oil consumed in an oil tank contains moisture. This moisture condenses into water that flows down the walls of the tank. It settles on the bottom of the tank where it eventually causes the tank to rust. Tanks with rust holes that are accessible sometimes can be patched with a rubber-and-sheet metal device that is fabricated in such a way that it can be clamped around the tank to seal the leak. Dead vegetation around the tank is an indication of leaking oil or spills. Underground storage tanks obviously cannot be as easily patched, and are even more likely to leak, thanks to the corrosiveness of oil.
Perhaps up to 30% of all underground residential tanks leak. Even in sunny California, oil was the fuel of choice early in the 20th century until gas piping took over the urban market in the 1930s, and tank removers there report that about 20% of the removed tanks still had product and were leaking, causing soil contamination (piping to the tank leak more often than tanks).
In the Northeast, where tanks are older, the percentage of bad tanks may be 50%. Slightly more than half of all spills reported on New York’s spill hotline are from residential tanks.
Evidence of water or soil contamination may trigger a pollution remediation order under federal (and some state) laws. Remediation costs range from $2000 to $1 million, with the average being about $40,000, according to some experts. In the absence of obvious contamination evidence, leaks generally are legally defined as a change in product quantity of .05 gallons per hour. Under this definition, some tanks could be losing slightly over one gallon per day and still not be condemned (yet). Nevertheless, such leaky tanks often contaminate ground water and invite lawsuits by neighbors, including those that may be quite distant (wells often receive water from locations that are hundreds of miles away).
Homeowners who wish to win or avoid a lawsuit from neighbors or officials can “take all due diligence” by hiring a tank tester to test the tank (perhaps $500; get one who is certified by local authorities). If the tank later is found to be faulty, the EPA superfund may pay remediation costs. Oil-supply companies also offer service contracts (perhaps $50 per year) that may cover the cost of replacing a tank. Regulations enforced in most communities require that any tank suspected of leaking (e.g., odors, oily soil, dying vegetation, etc.) must be reported to authorities. The life expectancy of tanks depends upon the type of tank, the type of soil, and climate. Rarely do typical steel tanks, used before 1990, last much more than a couple of decades.
Abandoned tanks also can pollute, especially if filled with water, as is allowed in some communities. They also eventually collapse, perhaps threatening life and limb. They should be totally emptied and then filled with inert solids in compliance with EPA and local regulations. Please note that oil companies that reclaim oil from tanks take only the good oil and leave the sludge that settles to the bottom of the tank. Do not fill a tank with inert solids if it still contains product (doing so can dramatically increase the eventual cost of remediation, and may violate regulations). If you discover an abandoned tank that has leaked, don’t panic. Call the local EPA office and your state’s water board to see if there are funds available for remediation. If not, the “statutory owner” may be required to pay for removal and remediation (the “statutory owner” may not be the current homeowner; consult your local authorities).
If the tank is not leaking, still it is a good idea to remove the tank (required by some relocation companies and some lending agencies). EPA guidelines call for all underground tanks to meet tough standards for corrosion resistance, effective December, 1998. State laws are much more stringent. Chet Riley is the Owner/Proprietor of CENTENNIAL Home Inspections.
Chet Riley is the Owner/Proprietor of CENTENNIAL Home Inspections. For any questions regarding home inspections, please call Chet at 585-293-2278. Or e-mail him at criley1@rochester.rr.com. Further information can be obtained at http://www.centennialhomeinspections.com/.