All Grease Interceptor Cleaning

Grease Interceptor Cleaning: When Pumping Is Not Enough

Routine pumping keeps a grease interceptor in compliance on paper. Professional cleaning keeps it functioning as designed — and the difference matters more than most operators realize until a problem develops.

What accumulates between pump-outs. A grease interceptor works by slowing wastewater flow enough for FOG to float and solids to settle. The separated layers are removed during pumping. What pumping does not remove is the grease film that coats the interior walls and baffles with each cycle, the hardened deposits that build up at the waterline and along the inlet pipe, and the accumulated solids that compact at the base of older interceptors. These deposits decompose anaerobically, producing hydrogen sulfide gas and reducing the effective working volume of the interceptor below its rated capacity.

How cleaning is performed. A technician with a pressure jetting truck directs high-pressure water through the interceptor at 1,500 to 4,000 PSI depending on interceptor size and deposit severity. The procedure loosens and mobilizes accumulated deposits on the walls, baffles, and inlet/outlet fittings. The loosened material is then vacuumed out and transported to a licensed disposal facility with a waste manifest. A thorough cleaning on a large outdoor gravity interceptor takes one to three hours.

Cleaning frequency versus pumping frequency. These are not the same service on the same schedule. High-volume operations may require pumping monthly but deep cleaning only quarterly. Your local FOG program may specify minimum cleaning intervals separately from pumping intervals. A reasonable baseline is professional cleaning every third or fourth pump-out cycle, with visual inspection at every visit to assess whether cleaning is warranted sooner.

Signs your interceptor needs cleaning now. Persistent sewer odour in the kitchen or near drains is the most common indicator. Slow drainage from floor drains or sinks upstream of the interceptor suggests reduced flow capacity from buildup. Visible grease film on baffle surfaces during a pump-out inspection that does not remove with vacuuming indicates hardened deposits requiring jetting.

Biological additives: useful supplement, not a substitute. FOG-digesting biological products can modestly extend the interval between mechanical cleanings in lower-volume operations. They are not accepted by any municipal FOG program as a substitute for scheduled pump-outs or mechanical cleaning, and they have no effect on hardened deposits that require mechanical removal.

Bundled versus standalone cleaning. Some FOG service providers bundle cleaning with every pump-out as a standard service. Others treat cleaning as a separate scheduled or on-request service. If your provider offers bundled service, confirm exactly what the cleaning component includes: visual inspection only, light rinse, or full-pressure jetting. The distinction matters for compliance documentation.

Document cleaning separately from pumping. Your waste manifest records pump-out volume and disposal. Cleaning should be documented separately — a service record showing the date, the procedure performed, and the technician's name. If your FOG compliance record is ever audited, the ability to show both pumping and cleaning documentation at appropriate intervals is the difference between a clean audit and a notice of violation.

Find licensed grease interceptor cleaning operators in your area using the directory above. Filter by service type, verify provider credentials on claimed listings, and contact providers directly for scheduling and service scope confirmation.