A grease trap is one of those pieces of restaurant infrastructure that only gets attention when something goes wrong, usually a backup during a busy service or a surprise question during a health inspection. Regular maintenance is far cheaper and far less disruptive than either of those situations, and it's worth understanding what the maintenance actually involves before you're dealing with an emergency.
What A Grease Trap Actually Does
A grease trap intercepts fats, oils, and grease from kitchen wastewater before it reaches the sewer line, allowing the lighter grease to float and separate from the water while solids settle to the bottom. Without it, that grease would travel into the sewer system, where it cools, solidifies, and causes blockages, both in your own line and potentially in the municipal system downstream. Grease interceptor sizing and installation requirements are covered under the Uniform Plumbing Code (UPC), which Washington has adopted statewide, and most jurisdictions require a functioning grease trap for any commercial kitchen for exactly this reason.
Why Skipping Maintenance Causes Real Problems
A grease trap that isn't pumped and cleaned on schedule eventually fills to capacity, at which point it stops doing its job and starts letting grease pass straight through into your sewer line. This is exactly how a restaurant ends up with a sudden, disruptive backup during service, usually at the worst possible time. It's also a real compliance issue. Many local jurisdictions inspect grease trap maintenance records, and a poorly maintained trap can result in fines or, in serious cases, a required shutdown until it's addressed.
What A Proper Maintenance Schedule Looks Like
Pumping Frequency Depends On Volume
A high-volume kitchen may need pumping monthly, while a smaller operation might go longer between services.
The 25% Rule
Many jurisdictions require pumping once grease and solids reach 25% of the trap's total capacity, not just when it's completely full.
Documentation Matters
Keeping service records is often a real compliance requirement, and it's useful to have on hand during a health inspection.
Between-Service Habits Help
Scraping plates before washing and avoiding pouring grease down drains extends the time between required pumpings.
How We Handle This For Kent-Area Businesses
Our commercial plumbing service includes scheduled grease trap maintenance, set up proactively around a realistic pumping frequency for your specific kitchen's volume rather than waiting for a problem to force the issue. We also handle the response calls when a trap has already caused a backup, though the honest goal is to get ahead of that situation with a real schedule instead. If your line has backed up more than once, it's worth having a proper sewer line inspection alongside the grease trap service, since repeated grease-related backups can sometimes damage the line itself over time.
We work with businesses across our coverage area, including several kitchens in Covington's retail and dining corridors, scheduling service during off-hours specifically to avoid disrupting a kitchen during its working day.
What A Service Visit Actually Involves
A proper grease trap service starts with pumping out the accumulated grease and solids, followed by a thorough scraping and cleaning of the trap's interior surfaces, since grease can build up on the walls even after the bulk of it has been pumped out. The inlet and outlet baffles get checked too, since a damaged or missing baffle lets grease bypass the trap's separation process entirely, defeating the point of having one installed.
After service, we provide documentation of the visit, including the date and the volume removed, which becomes part of your compliance record. Keeping a consistent paper trail matters more than most kitchen operators realize until an inspector actually asks for it, and having it ready without scrambling is one less thing to worry about during an already stressful inspection day.
Interceptor Size And Kitchen Volume
Not every grease trap is sized correctly for the kitchen it serves, especially in a space that's changed hands or expanded its menu since the trap was originally installed. An undersized interceptor reaches capacity faster than expected regardless of how well you maintain a pumping schedule, which shows up as more frequent service needs than a comparable kitchen elsewhere. If your kitchen seems to need pumping unusually often, it's worth having the interceptor's sizing checked against your actual current volume rather than just accepting more frequent service as the new normal.