What if an oil storage tank is installed at your property?

  • Buried oil tanks raise increasing environmental, safety, legal and economic concerns for home owners and home buyers because oil leaks underground or even within buildings can lead to both environmental damage and very costly cleanup operations.
  • Other types of storage tanks, such as above ground oil storage tanks and septic tanks present similar issues.

Environmental issues

  • Fuel oil leaks and soil or water contamination.
  • Economic issues: cost and risks of testing, tank removal, site cleanup.


  • Tank collapse. Major costs can be involved.
  • Regulations regarding identification, testing, and removal or abandonment of buried tanks vary widely from state to state.
  • Home fuel oil tanks are excluded from Federal Regulations about oil storage tank reporting and monitoring, but in some states and provinces, are addressed by state or local DEP/DNR/DEC agencies and regulations.
  • In any case, should a home fuel oil tank causes a release of oil into the environment, at that point the owner of the tank is not exempt from the other provisions of the Federal Regulations–the source of leak/spill would have to be stopped, a site characterization would have to be completed, and appropriate corrective action (cleanup) would have to initiated, and the incident would have to be reported.
  • Such components are not inspected during a home or building inspection unless specific prior test arrangements have been made with someone who specializes in this field. Tank inspection, other than casual visual inspection, tank tests, as well as removal or abandonment require that you use an appropriate expert. Some general advice is below.

Life Expectancy of Buried or Underground Oil Tanks

  • The common life expectancy of buried oil tanks is 10-15 years.We do not have the same data for gas tanks. Life may be similar. Buried tanks should be tested for amount of water present in tank bottom, and water should be pumped out. Water corrodes the tank and leads to leaks. 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.

Oil Tank Leak Failure Causes

  • Underground fuel storage tanks usually fail from rust perforation due to several effects of water inside the tank including, in the case of heating oil, combination of water with sulfur in the fuel, bacterial action, and other factors. External rust, unless very heavy, isn’t highly correlated with internal rust. Leaks can occur due to tank damage or at piping connections. A new tank involves significant expense.

Oil Tank Testing Procedures

  • Specialty companies and some oil companies have equipment to test buried tanks for leaks. Both simple pressure-testing and very sophisticated electronic testing are commonly used, mostly on commercial equipment rather than residential tanks. Testing for water in the tank is simple and can be done by any service person. Tank testing methods vary in risk to the tank, cost, procedures used, length of time to complete, and more.

Oil Tank Removal or Abandonment Methods

  • There are also proper methods of “abandoning” old unused buried tanks without actually excavating and removing them (provided there is not evidence of leakage). If a tank is not to be used, can involve significant expense. A proper abandonment procedure involves pumping out remaining fuel, confirming that there has been no leakage, cleaning the tank, and filling the tank with an approved filler, or removing it entirely. These measures, if required, involve significant expense.
  • Buried tank removal is handled by environmental services companies. Usually the specialist arranges testing, excavation, and disposal. Or tanks can be abandoned in place.

Environmental Issues & Regulations for Oil Tanks

  • Some state DEP/DEC/DNR (Departments of Environmental Conservation or similar agencies) have programs for registering buried tanks at any site storing more than 1000 gallons of fuel oil. Requirements for gas (auto fuel), or other fuels may be different. Eventually this concern may spread to smaller residential tanks. The concern is for leaks which contaminate the environment. Tanks located where they may leak into a local waterway or into the water supply are a special environmental concerns.

Above Ground Fuel Oil Storage Tanks

  • For years, factory-fabricated above ground liquid storage tanks such as those used to store home heating oil were shipped to job sites where dispensers, flame arrestors, vents and other accessories were added. Installers verified that the proper components were selected for compliance with fire and environmental codes. Unfortunately, code authorities still might find that requirements were not met.
  • During the past five years, manufacturers have introduced complete above ground storage tank (AST) systems with related accessories, such as dispensers, siphon valves, overfill protection systems and emergency venting devices, installed on the tank at the factory. Authorities Having Jurisdiction (AHJs) and manufacturers have requested that UL investigate entire factory-fabricated AST systems, to streamline the field-approval process and minimize problems associated with incompatible tank accessories.
  • UL has established a new product category and continues outlining requirements for Subject 2244, Above ground Flammable Liquid Tank Systems. UL has already completed its first product Listings to Subject 2244, and work on a proposed Standard was expected to begin in 1998.
  • Subject 2244 identifies four AST installations: aviation-fuel storage, motor-vehicle fuel dispensing, motor-oil storage, and generator-base tank systems. AST systems include a primary tank with integral secondary containment, provided by a double-wall tank or an integral tank and dike. Required and optional components are assembled prior to shipping. However, some components may require limited field assembly detailed in the installation instructions provided with each AST system.
  • To assist code authorities in facilitating the field evaluation process, UL has developed a Code Compliance Verification List (CCVL) for UL Listed AST systems. The CCVL documents how the tank complies with U.S. model codes, including National Fire Protection Association (NFPA) 30, Flammable and Combustible Liquids, and NFPA 30A, Automotive and Marine Service Stations, and the Uniform Fire Code (UFC). The CCVI, is included with UL Listed AST systems, and will be provided in the guide card information for Above ground Flammable Liquid Tanks (ECRU) in the 1998 edition of ULs Gas and Oil Directory.
  • The CCVL identifies the model code requirements for AST installations, including: supports, venting, piping and fittings, tank construction and openings, electrical installations, spill-control dispensers, and other accessories. The CCVL also documents installed components, including manufacturers’ names, model numbers, ratings and UL Listing information.
  • For example, motor-vehicle fuel-dispensing tank systems have requirements for sizing emergency vents in accordance with the exposed side walls and top of tank. The CCVL documents the required emergency venting for the tank, and identifies that the appropriately sized UL Listed emergency vent was installed.
  • The UL Listing markings on a tank system will identify the primary tank construction, For example, UL 142 and Subject 2244 indicate a steel tank; UL 2085 and Subject 2244 indicate a protected-tank system. UL markings affixed to ASTs that have been evaluated to Subject 2244 will also include the AST system type, such as motor-vehicle fuel dispensing, generator-base, aviation-fuel storage and motor-oil storage.

Government Contacts for Oil Tank Information & Regulations