Oil Tank Decommissioning Rules in Maine
This page covers closing a buried oil tank at a home or business in Maine, not the Maine Yankee nuclear plant. Maine regulates some oil tanks that federal law does not, such as underground heating oil tanks used on the premises. EPA lists Maine among the states with an approved UST program, and EPA's state programs page says approved programs operate in lieu of the federal program. Under 38 M.R.S. 565, the state rules apply to underground heating oil tanks used for consumption on the premises, which federal rules exclude. Chapter 691, the rule behind the Maine UST program, requires every underground oil storage tank to be registered regardless of use, size or product. Under 38 M.R.S. 563, single family homeowners are excused only from the registration fee for a tank at their personal residence. A basement tank sitting on or above the floor, where it can be readily inspected, is not an underground tank under state law.
Under 38 M.R.S. 566-A, an underground oil tank taken out of service for more than 12 months must be properly abandoned, and abandoned tanks must be removed unless removal is not physically possible or practicable. The owner gives written notice of the tank closure to Maine DEP in Augusta and to the local fire department. Chapter 691, as amended in March 2026, says the notice must reach DEP at least 10 business days before closure. It also says a tank out of service for 12 months must be removed within 60 days, unless DEP approves a request to keep it out of service longer. Closure in place, which Maine calls abandonment in place, is allowed only on four listed grounds, such as a tank beneath a building, or by variance. A deed notation must follow within 30 days.
Maine's Ground and Surface Waters Clean-up and Response Fund covers oil discharges from underground tanks, including heating oil tanks, but not the tank closure itself. Maine DEP's fund coverage page lists tank and piping removal and Appendix P site assessments among the costs the fund does not cover. It also excludes leaks discovered after October 1, 1998 from non-conforming tanks or piping. Under 38 M.R.S. 568-A, an application is due within 180 days of reporting the discharge, the standard deductible for an owner of one facility is $2,500, and the commissioner may waive the deductible for a personal residence in financial hardship. Our guide to closure in place versus UST removal explains what changes the scope of a closure job.
Under the Maine UST program, who must do the work depends on what the tank held. Chapter 691 requires the tank removal for a tank that ever held a Class 1 liquid, such as gasoline, to be supervised on site by a certified underground oil storage tank installer. A site assessment is required at closure, except for on-site heating oil tanks (other than heavy oil) and farm or residential motor fuel tanks of 1,100 gallons or less used only by the tank owner or operator. When one is required, the report goes to DEP within 45 days, and DEP does not certify site assessors. An actual oil leak must be reported within two hours at 1-800-482-0777. The state keeps a certified installer list; before hiring any contractor on this page for a gasoline tank, confirm its installer appears there.