Seattle Public Utilities — FOG / Commercial Kitchens
Not legal advice. Last verified 2026-09-24 · confidence high. Confirm with the city before you set a contract.
Minimum interval: No fixed calendar interval in the sources we cited.
Accumulation rule: No fixed calendar interval on the SPU commercial-kitchens page. Clean per manufacturer specifications; if specs are not available, no more than 25 percent of an interceptor should contain food or FOG buildup. SMC 21.16.310 B (as quoted by SPU): clean when more than 25 percent full of grease and food waste. Each business sets a schedule from buildup rate. Emulsifying agents, enzymes, bio-additives, or similar chemicals are prohibited (SMC 21.16.310 D).
Records: Retention period not stated on cited sources — keep invoices on site.
Hauler: Many businesses use service providers; SPU publishes a FOG service-provider list. The same SPU page also describes self-cleaning indoor units (scoop solids, add absorbent, bag to dumpster). Use a maintenance log (SPU PDF).
Permit: Any business with commercial kitchen plumbing fixtures and a King County Food Business Permit must install a grease interceptor (SPU; SMC 21.16.310 A). Even small delis, coffee shops, pizza parlors, and caterers.
Enforcement: SPU states fees range from $250 to $5,000 for non-compliance. The owner may also have to pay city costs from grease-laden wastewater damage. Confirm current amounts with SPU (greasefreepipes@Seattle.gov).
NFPA 96 frequencies (widely republished by fire departments): solid fuel monthly; high-volume quarterly; moderate semiannual; low-volume annual. Insurers and local fire inspectors can be stricter.