How to Find Underground Oil Tanks - Onsite Inspection of Properties for Evidence of Buried Oil Tanks InspectAPedia® -
How to find buried oil tanks
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This is a photo & drawing guide to finding buried oil storage tanks by visual inspection. 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.
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.
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.
Here are investigation methods that any home buyer, owner, or home inspector can apply to
reduce these risks by looking for evidence that a buried oil tank is or was at a property.
Also see Above Ground Oil Tanks: Visual Inspection.
SITE INSPECTION - Visual Inspection of a Building Site for Evidence of "Nearly Hidden" Buried Oil Tanks
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 this sketch 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.
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.
Here are Visual Clues of the Presence of a Buried Oil Tank at a Residential Property
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.
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.
Here are Indoor Visual Clues of the Presence of an Indoor or Outdoor Abandoned Oil Tank
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.
Building interior inspection for abandoned oil piping or fuel lines, or patch-marks on foundation walls where such lines may have been removed.
Our photo at above left shows a pair of copper oil lines exiting an basement foundation wall. These pipes were almost certainly connected to a buried oil tank. Is the tank still present?
Our photo at above right shows an "extra" pair of copper oil lines protruding out of the basement floor even though there was an indoor oil tank piped to the heating equipment. One could follow these older oil lines by markings in the concrete over to the building wall where they penetrated the wall to connect to an older outdoor buried oil tank.
Our photo below shows markings in a concrete basement floor that are characteristic of the floor having been cut open to install oil piping. Follow these marks to their destination; if you do not trace these markings to currently active oil piping then further investigation is needed: they probably mark abandoned oil lines an possibly an abandoned outdoor oil tank.
This photo provides evidence of buried oil lines and possibly an abandoned buried oil tank, as explained in text just above.
Historical information about the site is collected.
Oil company records may be checked for indications of deliveries or of prior tank service or removal
Ground scanning radar may be employed to locate large buried metal objects including underground oil tanks
Common sense observation of details, such as the location and placement of oil tank fill and vent piping, if present, can indicate the probable size and type of tanks in some cases.
An examination of the history of the property's heating systems - what equipment has been present, removed, changed.
Examine the building interior and outside for evidence of heating oil leaks.
Our photo 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.
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ABOVE GROUND OIL TANK INSPECTIONS
- "Visual Inspection of Above Ground Residential Heating Oil Storage Tanks - ASTs"
Advanced Home Inspection Methodology - Developing your X-Ray Vision
A Promotion Theory for Forensic Observation of Residential Construction. Discussion of methods to accumulate clues to enable
the detection of hard-to-find defects on buildings or other complex systems.
Thanks to Alan Carson and Bob Dunlop, Carson Dunlop, Associates, Toronto, for permission to use illustrations from their publication, The Illustrated Home which illustrates construction details and building components. Carson Dunlop provides home inspection education, publications, report writing materials, and home inspection services. Alan Carson is a past president of ASHI, the American Society of Home Inspectors
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
Our recommended books about building design, inspection, and repair, and about indoor environment testing, diagnosis, and cleanup are at the InspectAPedia Bookstore.
More Information on Building Diagnostic Inspections and Repairs
Oil Tanks - The Oil Storage Tank Information Website: Buried or Above Ground Oil Tank Inspection, Testing, Cleanup, Abandonment of Oil Tanks
Abandon a Buried Oil Tank, How To - Abandoning Commercial Underground Tanks, Russ Brauksieck, ASHI Tech. Journal, Vol.3 No.1 Spring 1993, P. 40-41 [Reprint]
Petroleum Bulk Storage J. Sibblies, NY State DEC, Advice to Home Owners and Home Inspectors about Oil Storage Tanks - summary from ASHI Chapter Seminar.
Septic Tank inspection, testing, diagnosis, repair
OIL TANK FAILURE CAUSES - Oil Tank Failure Causes - oil tank leaks are caused by corrosion, damage, soil conditions, other factors
TANK FAILURE RATES - Oil Tank Failure Rates - Oil Tank Leak Probability as a Function of Tank Age, Location, Condition, Soil Conditions and Other Factors
OIL TANK TESTING - - How Oil Tanks are Tested for Evidence Leaks, of Current or Previous Oil Spills
National Association of Oil Heat Service Managers, PO Box 380, Elmwood Park, NJ 07407
"Homeowners Guide to Fuel Storage," Agway Energy Products, Verbank, NY, November 1990
Web Link Exchange: Contact Us to list your website or contact information for oil tank testing, tank corrosion research, oil industry experts
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