Prohibited Sewer Discharges
Seattle Public Utilities states that Seattle Municipal Code prohibits wastewater containing more than 100 parts per million by weight of fats, oil, or grease. Visual evidence of grease buildup originating from a private sewer line can also constitute a violation.
Food-service businesses must install and maintain grease interceptors. Seattle also prohibits emulsifying agents, enzymes, bio-additives, and similar chemicals in interceptors because they can move grease downstream rather than remove it.
Separate Grease at the Source
Restaurants should:
- Collect used fryer oil in a closed container for appropriate recycling or disposal
- Scrape food and grease from cookware and dishes before washing
- Keep sink strainers in place
- Dry-wipe oily surfaces
- Prevent spills from entering storm drains
- Maintain interceptors before accumulation exceeds limits
Grease and solids removed from an interceptor must be handled through an appropriate disposal method or service provider.
Records and Enforcement
Keep interceptor cleaning, pumping, hauling, and repair records. Seattle warns that noncompliant businesses may face enforcement, penalties, and costs associated with grease-related damage to the sewer system.
Waste rules vary by material and quantity. Confirm current disposal instructions with Seattle Public Utilities, the waste hauler, and the receiving or recycling facility.
Frequently Asked Questions
Can used cooking oil go into the grease interceptor?
No. Collect bulk cooking oil separately rather than pouring it into sinks or the interceptor.
Can enzymes replace pumping?
No. Seattle prohibits enzymes, emulsifiers, bio-additives, and similar chemicals in grease interceptors.
Request FOG Compliance Plumbing
Request Restaurant Grease Disposal Regulations support from Seattle Plumbers for interceptor inspection, cleaning, repair, sizing, or installation. Confirm legal interpretations and facility-specific directives with the responsible Seattle or King County agency.