Washington Oil Tank Rules
There is no single statewide heating oil tank law. There is a code baseline, a local authority that applies it, and a state agency holding the money.
- Out of service trigger
- 1 year
- Decided by
- Local fire official
- Program cap
- $75,000
- Insurance scheme
- Ended 2025
The One Year Trigger
Most Washington fire districts apply the 2021 International Fire Code, section 5704.2.13, under which an underground heating oil tank out of service for a year or more must be removed from the ground or permanently closed in place. Seattle adopts the same section number into the Seattle Fire Code.
Closing in place has defined content rather than being a matter of judgment. Liquids and sludge out, lines detached, the tank filled completely with an approved inert solid, underground piping capped or plugged and above grade fill piping permanently removed.
Who Actually Sets The Requirement
PLIA states it directly: your local county fire chief or fire marshal defines how to address a heating oil tank that is no longer in service. That is why two properties a mile apart can face different paperwork and different fees.
In this market that means Seattle Fire Department Permit Code 6103 inside the city, and the King County Permitting Division outside it.
The Program That Replaced The Insurance
The Insurance Scheme Has Closed
The Heating Oil Insurance Program ended on 30 June 2025, and the Heating Oil Loan and Grant Program took over from 1 July 2025. Registered tank policies ended with it. Any page still presenting PLIA cover as an active insurance product is out of date.
What The Loan And Grant Program Covers
Up to $75,000 per applicant, made up of a cleanup grant of up to $60,000 for a single heating oil tank and a preliminary planning assessment grant of up to $7,000, with loan finance for infrastructure work such as converting to another heat source.
It Opens In Windows, Not Continuously
PLIA runs application cycles every spring and winter, each open for 45 days. The spring 2026 cycle closed in June 2026. Check PLIA directly for the current window rather than relying on a date on a contractor site.
PLIA Decides, Not Us
We can tell you the program exists, what it covers and what documentation the work produces. Whether a given property qualifies is the agency’s decision and we will never present a program ceiling as a payment.
Cleanup Runs On Separate Law
The fire code permit governs taking the tank out of service. If oil has reached the ground, reporting and cleanup sit with the Washington State Department of Ecology, and cleanup standards run under the Model Toxics Control Act at Chapter 173-340 WAC.
The Seattle Fire Department says as much in its own guidance, noting that fire code compliance does not itself require soil samples and that other environmental obligations may still apply.
The Seattle Tax That Was Repealed
Seattle adopted a 24 cents per gallon heating oil tax in 2019, intended to fund conversions away from oil heat. It was delayed three times and then repealed, with the repeal signed on 2 December 2022.
The conversion funding survived the tax. The city now runs rebates for households moving off oil heat through its Clean Heat program, which is a separate thing from anything to do with the decommissioning permit.
Common Questions
- Does Washington require an old heating oil tank to be dealt with?
- The requirement is set locally rather than by one statewide rule. Most Washington fire districts apply the 2021 International Fire Code, under which an underground heating oil tank out of service for a year or more must be removed or permanently closed in place.
- Who decides what has to happen to my tank?
- The Pollution Liability Insurance Agency puts it plainly: your local county fire chief or fire marshal defines how to address a heating oil tank that is no longer in service. In Seattle that is the Fire Department, and in unincorporated King County it is the county Fire Marshal.
- Is there still heating oil tank insurance in Washington?
- No. The Heating Oil Insurance Program ended on 30 June 2025 and was replaced from 1 July 2025 by the Heating Oil Loan and Grant Program. Pages still offering the old insurance are describing a scheme that has closed.
- How much can the state program pay toward a tank?
- Up to $75,000 per applicant overall, including a cleanup grant of up to $60,000 for a single heating oil tank and a preliminary planning assessment grant of up to $7,000. Eligibility is decided by PLIA, not by a contractor.
- How long do I have to keep the paperwork?
- PLIA states that a record of the tank size, location and date of closure should be retained by the property owner for up to five years. In practice keep it permanently, because the next buyer will ask for it.
Rules Aside, What Does Yours Need
Send the address. We will say which authority applies, which method the situation calls for, and what it costs in writing.