How much does it cost to decommission an oil tank in Seattle?

The permit is fixed and the work is not. Seattle Fire Department Permit Code 6103 costs $184.00 per tank as of the April 2026 form. The work itself is quoted per property, because a tank filled in place and a tank lifted out of a back garden are different jobs.

Do you need a permit to decommission an oil tank in Seattle?

Yes, and it has to be issued before the work. Seattle Fire Code section 105.6.19 requires a permit to remove, abandon or otherwise dispose of a heating oil tank, and the Fire Department will not issue one after the work is finished.

What does a decommissioned oil tank mean?

It means the tank was either lifted out of the ground or emptied, triple rinsed and filled with an inert solid such as sand, concrete slurry or foam, under a permit, and that a report was filed afterwards. Both methods count as decommissioning under the Seattle Fire Code.

Can you sell a house in Seattle with an oil tank?

You can, and many do. Washington sellers disclose an underground oil tank on NWMLS Form 17, so the question moves to the buyer and their lender rather than disappearing, which is why most tanks get dealt with before closing rather than after.

Does the fire code require a soil test when the tank comes out?

No. Seattle Fire Department guidance states that compliance with the Seattle Fire Code does not require a site plan or soil samples. Reporting and cleanup obligations under state environmental law are separate, and they still apply if the tank has leaked.

How long does the paperwork take after the work is done?

The certified decommissioner has thirty days. They return the Heating Oil Tank Decommissioning Report Form to the Fire Department and give you a copy inside the same window.

Oil Tank Decommissioning in Seattle, WA

Permitted removal and fill in place across the city and King County, with the report filed inside thirty days.

Technician checking a domestic steel heating oil tank with a handheld meter

Get A Written Quote

The address is enough to start.

What The City Record Shows

Most people arrive here because someone else asked for proof. An agent, a buyer, a lender or a relative clearing an estate. Pick the line closest to where you are.

A Record Is Not Always A Closed File

A decommissioning record filed with the Seattle Fire Department shows the permit was issued and the report came back. It does not say whether the tank was pulled or filled in place, and it does not say anything about the soil. Read which method was used before you rely on it in a sale.

Oil Tank Decommissioning Cost In Seattle

Two numbers behave differently. The permit is fixed and public: Seattle Fire Department Permit Code 6103 is $184.00 per tank on the April 2026 application form, and a separate permit is required for each tank on the property. The work is quoted per property.

Published local figures put a fill in place with no contamination at roughly $700 to $1,000, and a full excavation and removal with no contamination at roughly $5,000 to $10,000. Those bands come from a Seattle home inspection firm rather than from us, and they move the moment contaminated soil is involved.

We do not publish our own price list yet. Ask for a written quote and you get a figure for your property rather than a band from someone else’s.

Heating Oil Tank Decommissioning Methods

Seattle recognizes two. The tank comes out of the ground, or it is emptied, triple rinsed and filled with an inert solid such as sand, concrete slurry or foam. Both are decommissioning under the Seattle Fire Code and both need the same permit.

The Fire Department is unusually direct about the choice. It advises that a tank suspected of leaking should be removed rather than abandoned, and it states plainly that it cannot predict what future regulations will require of tanks left in the ground, so a tank filled today may have to come out later at additional cost.

If a sale is driving the timing, that warning matters more than the price gap. A buyer’s agent reading a fill in place record will sometimes ask for removal anyway. Selling a house with a tank covers how that negotiation usually runs.

The Permit Line Runs Through King County

Same county, same tank, two different regimes. Which side of the Seattle city limit the property sits on changes the fee, the certificate and whether anyone inspects.

Inside Seattle

Seattle Fire Department, Fire Prevention Division.

Permit fee: $184.00
Permit code: 6103
Who must run the work: ICC certified
Inspection: No
Report deadline: 30 days
Scope: 1 to 4 units, under 1,100 gal

Unincorporated King County

Department of Local Services, Permitting Division.

Permit fee: No fee
Applied through: MyBuildingPermit
Who must run the work: County certified
Inspection: No
You are given: Permit, rinse receipt, site plan
Scope: Single family, duplex, townhome to 4

Seattle figures from the Permit Code 6103 application form, revision 04/26. King County figures from the Permitting Division handout dated June 2024. Both are linked on the sources page.

The Chain From Permit To Report

Nothing here is optional and the order is not flexible. The single most common way a Seattle decommissioning goes wrong is the work happening first, because the Fire Department will not issue a permit after the fact.

Permit First

The application names the certified decommissioner and both work dates. It comes back stamped Approved to Proceed.

No permit is issued afterwards

Pump And Rinse

The tank is emptied and the interior triple rinsed to take out residual product and bottom sludge.

Disposal receipted

Fill Or Lift

The tank is filled with an inert solid or excavated and taken away, with the certified decommissioner on site throughout.

Certificate held on file

Report Filed

The decommissioning report goes to the Fire Department, and your copy arrives inside the same window.

Thirty days from completion

If either work date moves, the Fire Marshal’s Office has to be told in writing or in person by 9:00 am on the day the work actually happens. The form is blunt about the consequence: failure to do that renders the permit invalid.

What Sits Outside The Fire Code

Soil Testing Is Not A Fire Code Requirement

Seattle Fire Department guidance states that compliance with the fire code does not require a site plan or soil samples. That surprises most people. It does not mean the soil is fine, only that the permit does not ask.

Ecology Owns The Leak, Not The Fire Department

If a tank has leaked, reporting and cleanup run through the Washington State Department of Ecology under separate law. The Fire Department says as much in its own guidance and points to Ecology’s Northwest Regional Office.

Money Exists, On State Terms

The Pollution Liability Insurance Agency runs a Heating Oil Loan and Grant Program worth up to $75,000 per applicant, including a cleanup grant of up to $60,000 for a single tank. Eligibility is theirs to decide, not ours. See the Washington rules.

The Heating Oil Tax Never Took Effect

Seattle passed a 24 cents per gallon heating oil tax in 2019, delayed it three times and then repealed it, with the repeal signed in December 2022. Content still describing it as coming is out of date.

Where We Work

Across Seattle, including Ballard, Wallingford, Greenwood, Phinney Ridge, Ravenna, Bryant, Wedgwood, Laurelhurst and the rest of the city.

And in unincorporated King County, where the permit rules change: White Center, Skyway, Bryn Mawr, Fairwood, Klahanie, Cottage Lake, Hollywood Hill. Neighboring cities such as Shoreline, Burien, Tukwila and Renton run their own fire permits, so tell us the address and we will say which counter the application goes to.

Fewer than 10,000 Seattle homes still heat with oil, out of more than 180,000, on the city’s own November 2025 figure. It is a small pool of properties and an old one, which is why so many of these jobs surface during a sale.

Common Questions

How much does it cost to decommission an oil tank in Seattle?: The permit is fixed and the work is not. Seattle Fire Department Permit Code 6103 costs $184.00 per tank as of the April 2026 form. The work itself is quoted per property, because a tank filled in place and a tank lifted out of a back garden are different jobs.
Do you need a permit to decommission an oil tank in Seattle?: Yes, and it has to be issued before the work. Seattle Fire Code section 105.6.19 requires a permit to remove, abandon or otherwise dispose of a heating oil tank, and the Fire Department will not issue one after the work is finished.
What does a decommissioned oil tank mean?: It means the tank was either lifted out of the ground or emptied, triple rinsed and filled with an inert solid such as sand, concrete slurry or foam, under a permit, and that a report was filed afterwards. Both methods count as decommissioning under the Seattle Fire Code.
Can you sell a house in Seattle with an oil tank?: You can, and many do. Washington sellers disclose an underground oil tank on NWMLS Form 17, so the question moves to the buyer and their lender rather than disappearing, which is why most tanks get dealt with before closing rather than after.
Does the fire code require a soil test when the tank comes out?: No. Seattle Fire Department guidance states that compliance with the Seattle Fire Code does not require a site plan or soil samples. Reporting and cleanup obligations under state environmental law are separate, and they still apply if the tank has leaked.
How long does the paperwork take after the work is done?: The certified decommissioner has thirty days. They return the Heating Oil Tank Decommissioning Report Form to the Fire Department and give you a copy inside the same window.

Send The Address

Tell us the property address and what you have been asked for. You get a written quote by email, and a straight answer on which permit applies before anyone books a date.