Grease Trap Requirements
Tacoma, WA

FOG Compliance in Tacoma, WA

Food service establishments in Tacoma operate under a combination of federal EPA pretreatment standards, Washington state plumbing code, and city-level FOG ordinances. Together these rules determine how grease traps must be sized, how often they must be pumped, and what happens when a restaurant falls out of compliance. The city has approximately 1,703 food service establishments — every one of them subject to the rules summarized below.

Pumping frequency is the compliance rule restaurant owners interact with most often. In Tacoma, the rule is: Must be pumped when grease and solids reach 25% of interceptor capacity. This aligns with the 90-day US median enforced by most major cities. The city follows the Uniform Plumbing Code (UPC) for trap sizing and installation. Under Section 1014, which applies a fixture drainage load formula with a retention time factor, grease interceptors installed in Tacoma must meet minimum capacity thresholds based on the fixtures connected to them — 3-compartment sinks, dishwashers, pre-rinse stations, wok stoves, and floor drains on the cook line. The local minimum trap size is: Sizes referenced in local code: 500, 1000, 75 gallons.

Tacoma enforces the 25 percent rule: grease traps must be pumped before the combined FOG and settled solids reach 25 percent of the trap's total liquid depth. Inspectors measure the depth with a sludge judge or dipstick, typically at surprise visits. Exceeding the threshold at inspection triggers a notice of violation and mandatory emergency pump-out, regardless of the scheduled pumping cycle.

For a deeper explanation of the rules this city enforces, read our guides on how grease traps work and the 25/50 pumping rule.