Every commercial kitchen sends fats, oils and grease (FOG) down the drain, from fryer residue to dish rinse water. Grease interceptors catch it before it reaches the public sewer, where it hardens, narrows pipes and causes overflows. An interceptor only works if it is cleaned before it fills.
Local rules to know
The City of Medford's municipal code (section 11.505, Grease Interceptors and Other Pretreatment) makes the business responsible for inspecting, cleaning, repairing and maintaining its interceptor regularly at its own expense, and allows the city's Water Reclamation Division manager to set the cleaning frequency. It describes what cleaning means: removing all grease, wastewater, sludge and solids and scraping or pressure-washing walls and baffles. It also bars discharging FOG waste to the sanitary or storm sewer, and bars decanting it back into the interceptor.
Outside Medford city limits, much of the valley is served by Rogue Valley Sewer Services (RVSS), which runs its own FOG program, including a Regional Preferred Pumper Program for approved pumpers. If your business is in an RVSS service area, ask whether a pumper is on that list.
What a proper grease interceptor service looks like
- Full pump-out of grease, liquid and settled solids, not skimming the top layer.
- Scraping or washing walls and baffles, as the Medford code describes.
- Checking inlet and outlet tees and baffles for damage.
- Noting the condition and depth of grease and solids so the interval can be adjusted.
- Proper hauling and disposal of the waste.
- A service manifest or record you keep for inspections.
Picking a schedule
The right frequency depends on menu, volume and interceptor size. A fryer-heavy kitchen behaves very differently from a coffee shop. If the city or sewer agency has set your frequency, follow it. Otherwise start with a conservative interval, measure grease and solids at each visit, and adjust. Signs you are overdue include slow kitchen drains, odors near the interceptor, and grease visible at the outlet.
Kitchen habits that help
Scrape plates into the trash before washing. Collect fryer oil in a used-oil container for recycling rather than pouring it down a drain. Use strainers in sinks. Avoid relying on enzymes or very hot water to "move" grease; it tends to resolidify further down the line. Train new staff, since turnover is where good habits break down.
Small traps vs. large interceptors
Small under-sink grease traps can need cleaning very frequently and are sometimes handled by kitchen staff. Large in-ground interceptors need a vacuum truck. Tell us which you have, its size if known, and where its lids are when you request a free quote. After-hours service can be arranged to avoid closing during service.
Records and inspections
Keep every service manifest in one place, along with the interceptor's size and the frequency your sewer agency set, if any. If an inspector visits, being able to show consistent cleaning records is the simplest way to demonstrate compliance. Note the grease and solids depth recorded at each visit: if the interceptor is consistently full at cleaning time, the interval is too long; if it is consistently light, ask whether the interval can be extended.
Restaurants on septic
Some food businesses outside sewered areas discharge to an onsite septic system rather than a public sewer. Grease is especially harmful there, because it can pass into the drainfield and seal the soil. These kitchens should be particularly strict about interceptor maintenance and should talk to DEQ before changing menu, seating or hours in ways that increase flow. See our septic system types guide for background.
Tell us your interceptor size and current schedule when you request a quote, and we can suggest a starting interval.