Aboveground storage tank requirements in Washington

Project sequence

Current fire code: 2021 IFC with Washington amendments

Washington has adopted the 2021 International Fire Code through Chapter 51-54A WAC. The statewide edition became effective March 15, 2024. Local authorities enforce the code and may have locally adopted administrative requirements, so the project city, county, or fire district still matters.

Most AST permitting is local

Washington Department of Ecology states that it does not regulate most aboveground storage tanks. Local fire agencies, counties, and cities generally regulate and permit AST installations. For a buyer, that means the best early step is to identify the actual authority having jurisdiction before the tank is ordered.

Ecology's exceptions are narrower than they first appear

Ecology identifies two important exceptions. A tank can fall into the underground-storage program when more than 10 percent of the system is underground. Separately, aboveground petroleum tanks of 10,000 gallons or more at Class 1 oil-handling facilities are overseen by Ecology's spill-prevention program. Class 1 facilities are large oil-handling facilities such as refineries, terminals, and facilities transferring oil to or from tank vessels or pipelines. A normal truck-fed fleet or jobsite tank is not automatically a Class 1 facility simply because it is near water.

SPCC remains a separate federal test

EPA's SPCC rule can still apply even when Washington has no state AST registration requirement. The federal analysis looks at facility type, discharge potential, and aggregate oil-storage capacity. Do not use a single tank's gallon count as the entire SPCC test.

Example: fleet yard adding a diesel tank

For a Washington fleet yard, confirm the city or county fire authority, stored product, site access for deliveries, dispensing use, tank design and proposed location. Request the applicable local site-review checklist before ordering; state environmental exclusions and federal SPCC are separate determinations. A tank listing alone does not establish an approved installation location.

What to confirm before ordering

• Exact city, county, or fire district with permit authority
• Tank capacity, construction/listing, and secondary-containment approach
• Setbacks to buildings, property lines, public ways, and ignition sources
• Dispensing, venting, vehicle-impact protection, and electrical requirements
• Whether the site falls into Ecology's Class 1 facility rules or another specialized program

What not to assume

• Do not assume there is one statewide AST permit office for ordinary commercial tanks.
• Do not treat the absence of a blanket state registration program as the absence of local permitting.
• Do not apply Ecology’s Class 1 facility rules to an ordinary fleet/jobsite tank without confirming the facility category.
• Do not use one tank’s gallon count as the entire federal SPCC applicability test.

Primary sources

• Washington Legislature: Chapter 51-54A WAC, 2021 International Fire Code
• Washington Ecology: Underground and Aboveground Storage Tanks
• Washington Ecology: Class 1 facility spill-prevention plans
• U.S. EPA: Does SPCC Apply to Your Facility?