What are the grease trap requirements in Seattle, WA?

Food service establishments in Seattle must install and maintain grease traps or interceptors per local FOG ordinances. The city follows the Uniform Plumbing Code (UPC).

What size grease trap do I need for my restaurant in Seattle?

Grease trap sizing depends on your establishment's flow rate, number of fixtures, and local code requirements. 1,000 gallons minimum for gravity grease interceptors; hydromechanical interceptors per UPC sizing (typically 20-50 GPM). Use our free sizing calculator for a recommendation.

Grease Trap Requirements
Seattle, WA

Q: Do I need a grease trap permit in Seattle?

Yes, a FOG permit is required in Seattle. Fee: No separate FOG permit fee; covered under King County Industrial Waste discharge program.

FOG compliance regulations for food service establishments in Seattle, Washington. Serving 6,372 food service establishments.

At minimum every 90 days for t

Pumping Freq.

Required

Permit

Yes

25% Rule

UPC (Washington State uses Uniform Plumbing Code)

Code Base

Pumping Requirements

Frequency At minimum every 90 days for the first year; frequency may be adjusted based on monitoring records

25% Rule Applies

Permits & Enforcement

Permit Required Required

Permit Fee No separate FOG permit fee; covered under King County Industrial Waste discharge program

Max Fine $10,000 per day per violation under Seattle Municipal Code; King County may impose additional penalties

Complete FOG Regulations

Minimum Trap Size	1,000 gallons minimum for gravity grease interceptors; hydromechanical interceptors per UPC sizing (typically 20-50 GPM)
Pumping Frequency	At minimum every 90 days for the first year; frequency may be adjusted based on monitoring records
25% Rule	Yes — trap must be pumped when grease and solids reach 25% of capacity
Permit Required	Yes
Permit Fee	No separate FOG permit fee; covered under King County Industrial Waste discharge program
Maximum Fine	$10,000 per day per violation under Seattle Municipal Code; King County may impose additional penalties
Inspections	Annually; King County WTD inspects FSEs on a risk-based schedule
Record Keeping	Required — maintain pumping logs and manifests on-site
Plumbing Code	UPC (Washington State uses Uniform Plumbing Code)
Ordinance Ref.	Seattle Municipal Code Chapter 21.16 - Side Sewer Code; King County Code Title 28 - Industrial Waste; King County FOG Control Program requirements
Authority	King County Wastewater Treatment Division (WTD) Industrial Waste Program; Seattle Public Utilities (SPU) for local sewer connections

Additional Notes

Seattle's FOG program is primarily administered by King County WTD since the county operates the regional wastewater system. FSEs must install and maintain grease interceptors. The program requires kitchen BMPs, employee training, and proper hauler manifests. Garbage disposals are discouraged in FSEs. Records must be retained for 3 years minimum.

Regulations change frequently. Always verify current requirements with your local wastewater authority or plumbing inspector before making compliance decisions. Last updated: March 2026.