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Buying or Selling a Home with a Heating Oil Tank

Whether you’re buying or selling a home, it’s likely that at some point you’ll have questions about heating oil tanks. Some key issues to consider:  

For buyers


  • If the homeowner/seller knows of any tank no longer in use on the property, he or she must ensure that the tank is empty of oil.
  • The seller must also provide you with documentation that the tank has been emptied, as explained under the "For Sellers" section.
  • Note that a tank that has only been emptied of oil has not been “decommissioned." 
  • If the owner does not know if there’s a tank on the property, DEQ recommends the buyer hire a qualified expert to check for one. Always obtain owner permission prior to conducting any search activities.
  • If a tank is found on the property, have a service provider check to see if it has leaked if either of the following are true:
    • The tank is abandoned and has not been decommissioned, including soil sampling; or
    • The tank is active and has not been checked for leaks.
  • The current owner of the property is responsible for any necessary cleanup even if the leak happened before he or she bought the property. If you buy property knowing that a tank is present and no work has been done to determine if it has leaked, you also become responsible for any leaks discovered in the future. You then would have to contact an attorney for advice if you wanted to recover any costs from the prior owner.

For sellers

Nothing, if BOTH of the following are true:
  • The oil tank isn’t leaking or hasn’t leaked; and
  • You don’t know of any old, abandoned underground heating oil tanks on your property.

However, be aware that there may have been multiple small oil spills around the fill pipe when fuel was delivered. Or, the tank could have had problems in the past that you’re not aware of. Keep in mind that you’re responsible for cleaning up any contamination from a leak. DEQ recommends you check your tank for leaks before listing your home. You may want to consider having a licensed service provider test the soil underneath to determine whether or not it has leaked. This service may cost about $200 to $300.

You must do ALL of the following:
  • Ensure that any abandoned (i.e. unused) heating oil tank on your property is empty of oil,
  • Provide documentation to the buyer showing that the tank has been emptied, and
  • Leave the vent line in place unless you "decommission" the tank

  • Dated receipts from the company that pumped the oil out of the tank; or
  • Receipts from the oil recycling company if you pumped the tank yourself.

​DEQ recommends that you check for a tank before listing your property. You can:
  • Look for an oil fill pipe. It is usually close to the ground and close to where the furnace is located in your home.
  • Look for a vent pipe. You can usually see it attached for two to eight feet up the side of the house. It is 1.25 to 1.5 inches in diameter with a small vent cap on it.
  • Hire someone to look for an underground tank; this this typically costs $100 -200.
Note: If there’s been a leak, you as the property owner are responsible for cleaning it up to DEQ standards. If you believe the leak happened before you bought the property, you may want to seek advice from an attorney about recovering costs from the previous owner.

​Although you may choose not to look for a tank or have your soil tested, some buyers may require these things be done before the sale. Doing them ahead of time may save you time in selling your home. You are also required by state law (Oregon Revised Statute 105.464) to give the buyer a disclosure statement saying whether you know about any underground storage tanks or any contaminated soil or water on the property.

Contact your Realtor for more information on disclosure statements or further obligations that buyers or sellers may have about property information.

​Once the tank has been emptied of oil, actual decommissioning is voluntary.*

"Decommissioning" is a generic term for taking a tank out of service by cleaning it, then removing it or filling it in place with an inert material. If you – or the buyer – would like to have the decommissioning performed in compliance with state standards, you must:

  • Have the decommissioning project certified by a licensed service provider, and soil samples collected to confirm that no oil contamination was detected; and
  • Submit the certified report and documentation to DEQ with the associated filing fee ​to have the project registered. DEQ will send you a letter confirming the decommissioning project is complete.

*For example, you may choose not to clean the tank and remove it or fill the tank with an inert material or to have soil samples collected. However, be aware that some buyers or lenders may want the tank decommissioned to state standards so they do not assume liability for any problem found in the future.

​​​​You must notify DEQ within 72 hours of discovery, if you haven’t already done so, and clean up the leak to DEQ standards. To report the leak, call 1-800-742-7878. Then contact a Licensed Heating Oil Tank Service Provider for information on cleanup options. All service providers are required to report leaks when they are discovered.

​​Contractors or homeowners decommissioning their own tank must submit a report, and "certify" that their work is in compliance with all regulatory requirements and cleanup standards have been met.

The report and certification letter is submitted to DEQ. More information and fees please refer to the home page.

If the required documentation and fees have been submitted, the DEQ then registers the certified cleanup report and sends a letter to the responsible person. The DEQ audits various certifications and contractors to ensure that the work meets acceptable standards.

​It has come to DEQ's attention that contractors are being asked to recertify sites that have previously been issued a No Further Action letter by DEQ prior to 2/17/2000 or been certified as meeting standards by a contractor after 2/17/2000. The issue becomes what reliance, if any, can contractors and/or homeowners place on those earlier decommissioning or cleanup determinations. The advice DEQ has been giving is that the earlier determinations remain valid if:

  • No evidence exists to suggest a new release has occurred.
  • New site assessment data is consistent with the data submitted and relied on to make the earlier determination.
  • DEQ has not challenged the reliability of the earlier data through an enforcement action.

If the contractors or homeowners have any questions about the new information, they should contact the HOT technical staff for assistance or send an email.

On a related matter, DEQ is occasionally asked how long the results from a site assessment are valid where an active tank remains in the ground. Because new spills or releases from an active tank can occur at any time, DEQ advises that site assessment samples should be relied on for no more than 90 days. After 90 days it is advisable for new assessment data to be collected. DEQ will not accept site assessment data that is more than 90 days old if used to certify a decommissioning or cleanup.