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How to find buried oil tanks:
This article assists property buyers, owners, and inspectors in the location of buried oil tanks or the detection of evidence that an underground (or even an above ground) oil tank is or was in use at a property. We provide an illustrated guide to finding buried oil storage tanks by visual inspection.
The article and photographs used to show the reader ways to find buried oil tanks include examples of clues leading to the discovery of "nearly hidden" buried or underground oil tanks which were found at residential properties and which avoided very costly surprises later for the new owner.
[Click to enlarge any image]
Underground oil storage tanks, or UST's, whether still present or previously removed, involve a risk of costly oil leaks and soil contamination which may need to be addressed.
Before hiring an expert oil tank testing or removal company to find the oil tank, test an oil tank for leaks, and perhaps remove or abandon a buried oil tank in place, first we describe and illustrate a series of visual clues that can help you find the most likely location for a buried oil tank at any property.
Buried Tanks: Look at the property before deciding to hire a tank testing company for professional inspection and testing. You can obtain basic information such as the age (property and tank), tank location, and type of oil tank.
Our sketch at left, courtesy of Carson Dunlop, shows a common buried oil tank installation except that the oil line is shown leaving the bottom of the buried oil tank.
Modern practice usually connects a pair of oil lines to the top of a buried oil tank, avoiding picking up water and sludge from the tank bottom, and avoiding the chance that a leak in piping between oil and building interior will flood the inside of the building with oil.
But the sketch above shows that many buried oil tanks are installed close to the building foundation wall, usually parallel to the wall, since it's easiest to bury the tank in that position during new construction. (The sketch shows the tank at right angles to the wall so that we could portray the various piping arrangements with clarity.) So one of the first places to look for a buried oil tank is close to the building.
But that's not the only possible location for an outdoor buried oil tank at a property. We saw this coffee can in the bushes near a New York home and picked it up thinking we were just cleaning up trash left on the ground. Later in this article you'll see what we found.
Watch out: from a previous use, a buried oil tank may be present or may have been present at a property even if it is now served by an indoor, above ground oil tank or even by LP or natural gas. So don't assume that because you don't see a tank that none was ever used or present at a property. Make a visual site inspection for clues suggesting that one or more tanks is or was present.
Even an alert home buyer or home inspector, not charged with an environmental site survey (nor paid for one) might discover evidence of very costly buried tank problems at a property, simply by attending certain visual details and thinking about what they mean. For the case of buried oil tanks, the next few photographs show two cases of the discovery of a nearly-hidden outside oil tank fill pipe which led to the discovery of buried oil tanks. These tanks had not been properly abandoned, risking significant cost to the property owner or buyer.
The first three photos below show us exploring a hole in a bald patch of grass. Oil spills, such as during a heating oil delivery, can poison the soil so that even when no heating oil is visible or no odors remain, the grass may still refuse to grow in this spot. So we explored further as our photos show.
Many visual or historical clues may indicate that there is or was a buried oil or other fuel tank at a property.
Visible oil tank fill or vent pipes protruding from the ground, depressions near a building, or even areas of dead grass or plantings in a small spot where a buried or previous fuel tank fill pipe may have been installed - from spillage of fuel.
At one site this clue led to the discovery that the tank "removal" had consisted of nothing more than the unscrewing and removal of the fill and vent pipes from the leaky oil tank.
Age and type of property, existing oil fill and vent piping locations, existing oil tank size and ratings, abandoned heating oil lines, marks where equipment was previously mounted, footprints of old heating equipment, and other clues can form strong enough evidence of a risk of a hidden or improperly removed oil tank that we might then advise further investigation.
The next two photos show us exploring what appeared to be a simple coffee can tossed in the yard of a residential property.
The buried oil tanks discovered below these "nearly hidden" filler pipe openings needed to be tested for leakage and then properly abandoned - a significant expense
What is significant about this "abandoned" UST is that the evidence right at ground level (we could see down into the oil storage tank still in place but not in use) one could infer that the oil storage tank had not been properly abandoned. The risks include un-discovered heating oil leaks into the soil at this property.
See SIGNS OF BURIED OIL TANKS for a detailed discussion of the study of outdoor clues used to find a buried oil tank at a residential property.
In the author's view (DJF), oil tank testing services and professional environmental inspectors are expected to include both a visual screen of the property for clues such as these, and also a combination of other methods to detect buried oil tanks. Some clues that area strong evidence of a buried oil tank at a property are listed and illustrated below.
This photo (above) provides evidence of buried oil lines and possibly an abandoned buried oil tank, as explained in text just above.
Our photo at above left shows heating oil found seeping through the foundation wall in a crawl space. We suspected that a buried oil tank was or had been outside of this foundation wall and that it had leaked through the building foundation.
Further investigation discovered an abandoned heating oil tank buried just outside of this wall, under a driveway.
See INDOOR CLUES TO BURIED OIL TANKS for a detailed discussion of the study of indoor visual clues used to find a buried oil tank at a residential property.
Continue reading at BURIED OIL TANKS, INDOOR CLUES or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.
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Looking at property to purchase. Now heated with gas....has been for over 50 years. Oil tank buried somewhere on property...detectors cannot locate. Can we safely assume tank deteriorated?? Soil samples = no oil contamination thanx - C.T. 2/26/13
A competent onsite inspection by an expert usually finds additional clues that help accurately diagnose a problem or to get better clues about the history of oil tanks at a property:.
That said, here are some things to consider:
Not I nor anyone with a modicum of sense would promise you, by email, about a property of which we know nothing, that your site is free of risk of an expensive clenaup job due to a prior oil tank leak or spill based on the information in your note.
If you have reason to believe that an oil tank was previously at the property I would not assume that there was no leak or no remains of an old tank just because no one has seen anything.
With all of these dire warnings the question really is how much time, effort, and money are appropriate to pour into the ground trying to reduce risk of a hidden hazard.
Typically for a site that we know something about, people do soil testing in the most-likely tank locations and, absent any other data, for a residential property they give up, accepting the risk of buried hazards and future costs. It makes sense to think that no one in their right mind would install a buried oil tank at some great distance away from the building it serves, but indeed sometimes tanks are more distant than one might guess.
I have, for example, wandered in the woods of a property being bought by a friend; we found a large above ground oil tank hidden way back in the woods - from years ago; happly there was no leakage. Worse, a buried steel tank, if not properly abandoned, could have been left empty and could lead to a sudden soil collapse, even someone falling into the hole - with serious consequences. That tank was nowhwere near any existing building, but we found the remains of an old building - just the foundation that the tank had served. In fact it was the site history, signs of an abandoned road through the woods, and the discovery of the old foundtion that led me to the oil tank.
Remember that if you buy a property and do not find an oil spill, and if you are later selling the property and your new buyer finds a spill, it becomes your cost bear.
For a site where people have reason to be extra careful or concerned (there are factors that can raise our Fear-o-Meter or lower it) other options are available including consulting with an environmental expert who will audit site history, do a records search, and who might use ground scanning radar or other methods to make a more accurate search of the property, ending with a report that either found something or makes thje property owners comfortable.
Also see the FEAR-O-METER a promotion theory to convert risk of hidden defects & hazards into action thresholds, for a discussion of how an accumulation of inspection evidence leads to a rational decision to perform invasive or desctructive inspection measures.
You probably want some combination of research into site history, visual inspection, and testing to decide how much risk remains to you. But if we knew that there had been a buried tank at a property, or were pretty sure there was one that had not been professionally abandoned, presuming it magically disappeared with no work on anybody's part is a bit of a risky proposition.
In sum, when do we quit looking for a buried hazard? Armed with the information you have or can find out, and the extent of property that remains unexplored, and the probability that a buried oil tank was actually installed at some remote spot not near any building, you will decide how much remaining risk there is and and how much to spend on reducing that risk (you can't get it to zero in some cases). That's for you to decide with some advice from an on-site expert.
Thanx....just had it inspected..
No tank,no soil contamination
be sure to keep documentation - in the event of a future property sale that will help.
(Oct 14, 2014) Rosa said:
We had a property where we changed oil heating to electric heating.The property was sold 3 more times in a span of 28 years. the current owners dug up the soil to put in a French drain and came upon an oil tank. they had it removed and are now suing the person that sold the the property for damages. in turn the person who sold them the property is suing the person who sold it to them and he is suing us. Who is liable in this case? we sold the property in 1986.
Rosa this is a legal question for your attorney and the reply will most likely depend on the terms of the various contracts of sale.
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