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Heating Oil Underground & Above ground Oil Storage Tank Life Expectancy InspectAPedia®  -   Life expectancy of buried or above ground oil tanks Factors affecting oil tank life: indoors, outdoors, or buried tanks

This article discusses estimates of oil storage tank life for buried oil tanks and above ground oil storage tanks. How long an oil storage tank can be expected to reliably contain its oil and not to leak depends on quite a few variables which we discuss here. Also see OIL TANK FAILURE RATES and if your oil tank is leaking see OIL TANK LEAK ADVICE.

Some things that can shorten the life of an oil tank can be avoided or corrected. The photo shows how a leak develops and appears in an indoor oil storage tank, forming a stalactite of oil and sludge hanging from the bottom of the tank. Because an oil tank often rusts through from the inside out, the exterior of an oil tank may look fine but in fact it could be paper thin and easily punctured, even by a finger!

The life expectancy of oil tanks is helpful in planning for storage tank testing and storage tank replacement. This is a chapter of our "Heating Oil Underground & Above ground Oil Storage Tank Leaks, Testing, Problems & Solutions, Home Buyer's / Home Owner's Guide" which offers extensive free un-biased oil storage tank inspection and testing advice for property buyers and owners.

Home buyers should be sure to review OIL TANK TESTING - Leaky Heating Oil Tanks - How Oil Tanks are Tested for Evidence Leaks, of Current or Previous Oil Spills andOIL TANK LEGAL ISSUES - Home Buyers and Home Owners Guide to Leaky Heating Oil Tanks - What to Do About & When to Report Oil Tank Leaks. Leaky Heating Oil Tanks.

Home owners who have old oil tanks above ground or any age oil tank below ground should also be sure to review OIL TANK ABANDONING PROCEDURE - Abandoning Commercial vs. Residential Underground Oil Storage Tanks (UST) - Procedures & Regulations A separate website addresses Septic Tanks.

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OIL TANK LIFE - Life Expectancy of Buried or Underground Oil Tanks

While we've found them lasting longer, a common life expectancy of buried oil tanks is 10-15 years. At about 20 years, the risk of leaks from buried steel oil tanks becomes significant. Leaks can occur earlier if a tank was damaged at installation or was not properly piped.

Even if you think the tank is ok, young, and not leaking, buried oil tanks, should be tested for water in the tank bottom. Water should be pumped out since it corrodes the tank and leads to leaks. Oil tank leaks can also be due to damage at time of installation, improper installation, corrosive soils, or piping defects. If the tank is to remain in use, ask your fuel supplier about using an additive or other methods to help remove water.

In New England for a two year period [1984-5] among customers who have buried heating oil tanks (16% of total customers) surveyors found an average of 1.7 tank leaks per thousand customers. They also found 2.5 fuel line leaks per 1000 customers. (Fuel Oil and Oil Heat magazine, August 1985 p.18.) We do not have similar data for buried gas tanks in residential application.

Factors in Oil Storage Tank Life and Oil Leak Occurrence

Above Ground Indoor Oil Storage Tanks

• The first tank shown here has seepage at its fill and vent fittings, a rather typical and trivial problem which is hard to avoid unless meticulous sealant application is used during assembly of the fill and vent piping - the machining at the tank top and on larger diameter piping is often a bit rough. The second tank shown here is an older one which shows the same seepage around the tank top fittings. But what about those oil stains on the lower left tank body? The tank may be leaking at its seams or from perforations. Further investigation is warranted.
• Water accumulating in the tank from bad oil deliveries or from wide temperature swings and in-tank condensation. Test the tank for water and remove water from the oil tank by pumping (large amounts) or by absorbing chemicals or pads (small amounts of water).
• Poorly-made plumbing connections. Inspect and correct any leaky fittings.

Above Ground Outdoor Oil Storage Tanks and Life Expectancy Factors

Include the causes listed above and add the following oil storage tank life determining factors:

• Exposure of the oil storage tank to wider temperature swings, especially in cold and humid climates can increase in-tank condensation
• Exposure of the tank filler or vent pipes to rain, especially to roof runoff for tanks mounted under the eaves of a home and especially if a proper cap is not kept on the tank filler pipe or if the vent pipe is not properly installed and shielded.
• External oil tank rust due to exposure to the weather. Many small tanks, 250g or 275g, were never rated for outdoor use, as you may easily ready by examining the embossed UL label affixed to most tanks. Manufacturers of newer oil storage tanks in this size range appear to have removed this "indoor use only" wording from the UL label, as you can see in the photo shown here. We have not learned whether the standard was changed, the tanks were changed, or simply the label was changed. An outdoor tank should be protected from the weather and in freezing climates should be given shelter and warmth.
• Improper oil tank installation / installation of improper oil tank type: the second photo above shows an old, indoor-oil tank which was moved outside and placed onto the soil surface below a deck, and then was half buried. What is this tank, a buried tank or an above ground tank? It was not rated for outdoor use at all and is at extra risk of leakage due to placement of the tank body directly in contact with the soil.
• Improper oil storate tank supports, such as failure to keep the outdoor tank off of the ground, to install it at the proper pitch and direction of pitch, and to install it on level, secure piers can lead to a tank tipping over, ripping open an oil line, and obvious catastrophes of oil spillage and heat loss.

We discuss the inspection of above ground oil storage tanks at ABOVE GROUND OIL TANK INSPECTIONS.

What Determines the Life of Buried Oil Storage Tanks

Include the causes listed above and add the following: Exposure of the tank filler to surface runoff (as shown in the photograph): some oil tank installers or homeowners insist on installing the tank filler flush with or even below ground level, perhaps for aesthetic reasons. This detail increases the risk of snow melt or surface runoff entering the oil storage tank, particularly if the filler cap is left off or if its o-ring or gasket seal is not perfect. Smaller tanks which have been buried, such as a 250g or 275g tank, especially if more than 10 years old, are suspect: we have not ever found one of these that was labelled as approved for outdoor below-ground use. If you have a buried oil tank in this size range further investigation is warranted. Mechanical damage to the tank during installation, such as scraping its protective coating (if there was one), or omission of any protective coating on the buried tank. Damage might occur for example, by scraping the tank with equipment used to move it, or by setting the tank into a hole atop a rock or other debris. Fiberglass or plastic tanks may be more vulnerable to serious mechanical damage during installation. Corrosive soils - soil corrosivity may be a significant factor in buried steel oil tank life in areas of soils with a high corrosivity index. Plastic or fiberglass tanks are less likely to be affected by soil corrosivity. Amount of ground water in soil: wet soils increase the risk of corrosion on buried steel tanks and increase the risk of leaks into a damaged (or poorly plumbed) tank for both steel and plastic/fiberglass oil storage tanks.

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OIL TANK HOME
ABANDONING OIL TANKS ABOVE GROUND OIL TANK INSPECTIONS
BURIED OIL TANK ADVICE
BURIED OIL TANKS, FINDING
FLOATING UP OIL STORAGE or SEPTIC TANKS
FUEL OIL TYPES & CHARACTERISTICS
HEATING OIL EXPOSURE HAZARDS, LIMITS
HEATING OIL SHELF LIFE
OIL TANK ABANDONING PROCEDURE
OIL TANK FAILURE CAUSES
OIL TANK FAILURE RATES
OIL TANK GAUGES
OIL TANK INSPECTION REPORTS
OIL TANK DEFECT INSPECTION
OIL TANK PIPING DEFECTS
OIL TANK LEGAL ISSUES
OIL TANK LEAK ADVICE
OIL TANK LIFE
OIL TANK REMOVAL COs
OIL TANK REMOVAL FINANCIAL AID
OIL TANK REGULATIONS
OIL TANK SLUDGE
OIL TANK STANDARDS
OIL TANK TESTING
OIL TANK TESTING COs
OIL TANK WATER CONTAMINATION

• The rate or frequency of oil tank leaks or oil storage tank failures, focused on underground storage tanks or USTs, is discussed in detail at TANK FAILURE RATES Oil Tank Failure Data - Oil Tank Failure Rates - Oil Tank Leak Probability as a Function of Tank Age, Location, Condition, Soil Conditions and Other Factors. TANK REGULATIONS outlines who, when, and how oil leaks and spills must be reported to environmental authorities.

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]
• Above Ground Oil Tanks: Visual Inspection of Oil Storage Tanks for evidence of leaks, damage, improper piping - photos and text
• Above Ground Oil Tanks Checklist, an Oil Company's advice
• Above Ground Tanks UL Standards, UL Tank Listing Standards, guidance for home owners, buyers, and inspectors
• Buried Oil Tanks - Finding How to Find Buried Oil Tanks and "Nearly Hidden" and Leaky Oil Tanks - photos and text.
• Buried Fuel tank - Advice - Buried FUEL Tank - GAS or OIL advice for home buyers, home owners, inspection report language for homes where a buried oil tank is or was installed
• Environmental Issues & Regulations for Oil Tanks, Registration, Abandonment, Leak Reporting
• Home Inspection Report Language Library: Buried Oil Tanks, Buried or aboveground oil tank advice for home buyers and home owners, where a buried oil tank is or was installed, also home inspection report language for oil tanks
• Home Inspection Report Language Library: Visible Defects in Oil Tank Installations, Tanks, and Heating Oil Piping
• Home Inspection Report Language Library: Gas Fuel Piping or Tank Faults Basic advice - home inspection report language suggestions
• Home Inspection Report Language Library: Oil Tanks text file list © Oil and Other Storage Tank Leaks, Testing, Abandonment, Inspection - UST home inspection report language files - Reference List
• Indoor Environment Website Indoor Building Environmental Hazard Detection, Testing, Repair, & Prevention - Main Web Page
• Leaky Heating Oil Tanks - Advice for Home Owners or Buyers: caused of leaks in oil tanks, oil tank testing alternatives, what to do about leaky tanks: D. J. Friedman, ASHI Tech. Journal, Vol.2 No.1, Winter, 1992 p. 42-43 Illus
• Leak or Failure Rates for Home Heating Oil Tanks
• Legal Issues Regarding Buried Oil Storage Tanks K. S. Rea, Attorney, summary from ASHI Chapter Seminar.
• Primer on Petroleum Bulk Storage Tanks & Petroleum Contamination of Property Paul H. Ciminello, ASHI Tech. Journal, Vol.3 No.1 Spring 1993, p 35-39
• 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
• "How do you choose the right tank testing method?", Cynthia Johnson, Fuel Oil & Oil Heat Magazine, November 1995
.
• 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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