Heating Oil Cleanup Requirements & Standards

Heating Oil

Confirmation of the existence of contamination or suspicion of contamination resulting from a spill or release of heating oil should prompt several pertinent questions:

  • What reports must be made, and to whom?
  • When does a cleanup have to occur?
  • What is the required level or standard of cleanup?

Cleanup Requirements

Chapter 173-340 WAC (Model Toxics Control Act – Cleanup) addresses the requirement for expeditious cleanup of contamination and the requirement to conduct remedial action necessary to protect human health and the environment. Reporting requirements address contamination that may pose a threat to human health and the environment.

If contamination from a spill or release from a heating oil tank does not pose an imminent or substantial threat to human health and the environment, cleanup does not have to be accomplished immediately. A property transfer may well prompt a lender or purchaser to require cleanup prior to completion of the property transfer, but there is no legal requirement to effect an immediate cleanup.

Reporting Requirements

Report to Ecology any release to the environment.

You must notify the Department of Ecology (Ecology) of any release to the environment. You can notify Ecology by phone, email, or using an online form. View Contact information for the Department of Ecology.

Ecology Offices

Eastern Region (509) 329-3400
(Adams, Asotin, Columbia, Ferry, Franklin, Garfield, Grant, Lincoln, Pend Oreille, Spokane, Stevens, Walla Walla, and Whitman counties)

Central Region (509) 575-2490
(Benton, Chelan, Douglas, Kittitas, Klickitat, Okanogan, and Yakima counties)

Northwest Region (425) 649-7000
(Island, King, Kitsap, San Juan, Skagit, Snohomish, and Whatcom counties)

Southwest Region (360) 407-6300
(Clallam, Clark, Cowlitz, Grays Harbor, Jefferson, Mason, Lewis, Pacific, Pierce, Skamania, Thurston, and Wahkiakum counties)

If the release has impacted surface water or groundwater (e.g. lakes, rivers, creeks, or storm sewers), you must also notify the Washington Emergency Management Division at 1-800-258-5990.

Cleanup Standards

Corrective action to remove or treat contamination from heating oil should not, in most cases, be perplexing. Dealing with contaminated soil is usually not complicated. The presence, however, of contamination of surface or groundwater, or the presence of fumes in a basement or crawl space may complicate the problem and lead to more involved or costly courses of corrective action.

Chapter 173-340 WAC ( Model Toxics Control Act – Cleanup) provides guidance and requirements related to the cleanup process, cleanup standards, reports, etc. The Rule provides several approaches for establishing cleanup levels.

The Method A approach should be used for sites undergoing routine cleanup actions and for establishing soil cleanup levels. Heating Oil is essentially diesel fuel and the appropriate hazardous substance measured for corrective action is TPH (total petroleum hydrocarbons).


Although at this time there is no legal requirement to do so, you should keep a copy of all correspondence related to a heating oil tank project, including copies of any lab analyses. It is advisable to take photos during any testing, corrective action or related activities, and maintain copies.