Department of Environmental Conservation

D E C banner

Underground Heating Oil Tanks: A Homeowner's Guide

Most home heating oil tanks are not regulated by New York State's Petroleum Bulk Storage (PBS) regulations because they have a capacity of less than 1,100 gallons (see the PBS Registration Fee Worksheet (PDF, 11.65 KB) for more information). However, some delegated counties have regulations that do apply. If you live in one of the four delegated counties: Nassau, Suffolk, Cortland, or Westchester, you are encouraged to contact the appropriate county Department of Health agency to determine whether such smaller heating oil tanks are regulated.

Even if your heating oil tank is unregulated, a leak could be very unfortunate, not only for the environment, but for your pocketbook, too. When an underground tank or pipe leaks, the cleanup can cost tens of thousands of dollars and, if your homeowner's insurance policy contains a "pollution exclusion" clause--which many do--you could get stuck with the bill.

When a tank is found to be leaking, additional work is usually needed to determine the extent of the problem and the amount of cleanup required. Contamination must be reported to the Spills Hotline by calling 1-800-457-7362.

One way to address these concerns is to remove your underground tank and replace it with a new underground tank or a new aboveground tank installed in your basement, garage or storage shed.

Why should I consider replacing my underground tank?

Like all equipment, tanks have a limited useful life and eventually have to be repaired or replaced. Many underground home heating oil tanks are similar to the 275-gallon steel tanks you have probably seen in basements or garages. These tanks were not designed to be buried and, if left in place, will eventually corrode and leak. Even larger tanks that were specifically designed for underground use will leak if they are not protected from corrosion.

If you notice an unexplainable increase in your home heating oil use, your tank may be leaking. But that information alone is not always an accurate indicator. In some cases, water may leak into the tank or the leak may occur only when the tank is full, thus hiding the problem from the homeowner.

While possible, the odds are that an underground tank 10 or 15 years old probably is not leaking. However, the likelihood of a leak increases as the tank gets older. Even small, slow leaks can pose a serious threat to your family, your neighbors and the environment if they go undiscovered for a long time. And if your tank does leak, you may face a costly cleanup. Having an old tank replaced with a new, modern double-walled underground tank or new aboveground tank can save you both money and anguish in the long run. Don't forget to replace piping when a new tank is installed. Contract with a reputable equipment dealer to be sure the tank is installed with overfill alarms, vents and other vital equipment.

How much does it cost to remove an underground tank?

Removal can cost from $1000 to $5,000 depending on the size of the tank, its condition, and how easily it can be reached.

For the best price, shop around. Check online for environmental contractors in your area or contact your oil company. Get cost estimates from several contractors. They can provide you with an accurate estimate by visiting your home to determine both where your tank is located and whether there are obstacles to getting the job done. Compare services and be sure to check references. As with any substantial home improvement, get a written cost estimate and a contract that outlines the services to be performed before work begins.

Can I test my tank for leaks instead of digging it up?

Yes. However, it is important to consider that no test can predict what will happen next year, next month, or even the next day. If you have an old steel tank that is not protected from corrosion, your money may be better spent on tank removal since you will have to dig the tank up anyway if the test reveals it is leaking.

Although a commercial tank tester provides the most reliable check for leaks, a general evaluation for a leak can be performed by checking for a drop in the oil level in the tank when oil is not being consumed.

Can I just empty the oil from my tank and leave it underground?

Yes, if certain other measures are taken.

State law requires that aboveground and underground heating oil tanks be emptied, cleaned and purged of all vapors. If an underground tank is to be removed, the vent line and fill line must also be removed or the fill line must be capped with concrete. If the underground tank is to be closed in place (that is, filled with an inert material such as sand), the vent lines must remain open and intact and the fill line capped or removed.

The best choice is to remove the tank. This will enable you to check for soil contamination and avoid future sink holes which might occur if the tank collapses.

In addition, should you decide to sell your home, a bank or the buyer likely will ask for an environmental assessment or the removal of the tank, which could make closing your tank in place costlier than removing it from the ground in the first place.

How will I know if my tank has leaked?

Contamination may be indicated by signs of a damaged tank or pipe, soil that is stained or gives off strong oil odors, a sheen on the groundwater, or environmental test results. Sampling and analysis is recommended if the tank is located near any wells, drinking water supplies, wetlands, ponds or streams, or if there are any indications that contamination is present.

When shopping for a contractor, ask if they have the capability of doing an environmental assessment.

What if contamination is found?

Don't panic; the problem could be minor and relatively simple to correct. Take action as soon as possible because addressing the problem now will prevent a higher cost and damage later.

If you find contamination or suspect there has been a leak (for example, loss of fuel), contact the nearest DEC regional office or call the Spill Hotline (1-800-457-7362). DEC will provide you with guidance and assistance.

How can I obtain more information?

Call DEC'S Helpline at (518) 402-9543, or the nearest regional office.


  • Important Links
  • PDF Help
  • For help with PDFs on this page, please call 518-402-9543.
  • Contact for this Page
  • NYS DEC
    Environmental Remediation
    625 Broadway
    Albany, NY 12233-7020
    518-402-9543
    Send us an email
  • This Page Covers
  • Page applies to all NYS regions