120 John Dodd Rd, Spartanburg, SC 29303
Restaurant Grease Trap Cleaning Guide: Essential Care Tips
Hey! John (Ivan) Rusev here, from Rock Solid Septic & Excavation. While mostly what we do is residential work, a sizable chunk of it is restaurant grease trap service. They are easy to overlook until a kitchen develops slow drains or a wastewater backup. In this guide, I cover what grease traps do and how to keep them running.
What Is a Grease Trap?
A grease trap or grease interceptor is a device that commercial kitchen wastewater flows through to remove fats, oils, grease, and food solids before the water enters the sewer or septic system. Small hydromechanical grease interceptors are commonly installed indoors near specific fixtures. Larger gravity grease interceptors are generally installed outside and receive wastewater from multiple approved kitchen fixtures.
How Grease Traps Function
The grease trap unit works on the basis of density, just like a septic tank. Wastewater from approved kitchen fixtures enters the unit and slows down, allowing lighter fats, oils, and grease to rise while heavier food solids settle. The wastewater between these layers then exits toward the sewer or onsite wastewater system. The exact fixtures connected to the unit must follow the approved plumbing design and local requirements. Fats and oils float to the top, while the solids sink to the bottom. The clarified water between them exits out to the sewer line, with fats and solids retained within the trap.
Restaurant Grease Trap Maintenance
Most municipalities require food service establishments to install grease traps and keep them at a certain level and to record the date of servicing according to local codes. Proper grease trap maintenance means checking grease levels regularly and cleaning each unit on the schedule appropriate for its size and type. ReWa requires in-ground grease interceptors in its service area to be maintained at least quarterly unless an alternative schedule is approved by a Commercial Pretreatment Inspector. The correct interval depends on the unit, grease accumulation, and the applicable wastewater authority. Restaurants that record the amount of grease and stick to maintenance schedules don't have to worry about the costly emergency situations that improperly maintained grease traps cause.
Adhering to some best practices will greatly improve the performance of your grease trap. Make sure that you scrape plates into the trash can before washing, don't pour oil down the sink, and place strainers in the kitchen drains to catch food particles. Follow these habits, and the accumulation of grease in the traps will slow down drastically. They will be serviced less frequently, which means less money spent on cleaning and maintenance each quarter. Maintenance records and a properly functioning interceptor also help the restaurant demonstrate compliance during wastewater pretreatment inspections.
Adhering to some best practices will greatly improve the performance of your grease trap. Make sure that you scrape plates into the trash can before washing, don't pour oil down the sink, and place strainers in the kitchen drains to catch food particles. Follow these habits, and the accumulation of grease in the traps will slow down drastically. They will be serviced less frequently, which means less money spent on cleaning and maintenance each quarter. Maintenance records and a properly functioning interceptor also help the restaurant demonstrate compliance during wastewater pretreatment inspections.
Cleaning Your Grease Trap
Cleaning requirements depend on the type of unit. A small indoor trap may be cleaned by trained restaurant personnel when local rules allow it. The contents must be removed completely, the walls and baffles cleaned, and the waste contained and disposed of by an approved method.
A large in-ground grease interceptor should be completely pumped by an approved transporter. Removing only the floating grease is not sufficient because settled solids and material on the walls and baffles remain inside. ReWa requires complete pump-out and does not allow skimming of in-ground interceptors.
Soap, enzymes, bacteria, emulsifiers, or degreasers should not be used as a substitute for cleaning. These products can move grease farther into the plumbing or wastewater system instead of removing it from the premises. During service, the technician should also inspect the baffles, covers, and interior for corrosion or other damage.
A large in-ground grease interceptor should be completely pumped by an approved transporter. Removing only the floating grease is not sufficient because settled solids and material on the walls and baffles remain inside. ReWa requires complete pump-out and does not allow skimming of in-ground interceptors.
Soap, enzymes, bacteria, emulsifiers, or degreasers should not be used as a substitute for cleaning. These products can move grease farther into the plumbing or wastewater system instead of removing it from the premises. During service, the technician should also inspect the baffles, covers, and interior for corrosion or other damage.
What Years of Grease Buildup Can Do
We saw the damage that improper grease disposal can cause during a residential septic service in Inman. The equipment was different from a restaurant grease interceptor, so this is not a commercial grease-trap case, but it shows why grease should be captured and removed before it reaches downstream piping. A homeowner's toilets would gurgle every time water ran in the kitchen. Alex and Bailey opened the tank and found the inlet baffle jammed full of 10-year-old hardened grease from cooking oil that never got intercepted. The grease had formed such a dense cake that it narrowed the opening until water started to push back into the fixtures. The home did not have a grease interceptor. In a restaurant, an overfilled or poorly maintained interceptor can likewise allow FOG to reach downstream piping, where it may contribute to restrictions and backups. Anyway, the guys pumped the tank, cleaned the baffle, ran the water, and confirmed the flow. One $400 visit, and gurgling disappeared.
Need your grease trap cleaned?
If your grease trap is overdue for service or you are unsure about local requirements, call us at (864) 431-2822. We serve restaurants across Spartanburg, Greenville, Cherokee, Pickens, and Anderson counties and can recommend the right cleaning schedule for your unit.
FAQ
Most restaurants hire a professional grease trap cleaning service that pumps out accumulated grease and solids, scrapes down the interior, and disposes of the waste according to local regulations. Some smaller under-sink traps get cleaned in-house by staff trained on the process, although larger interceptors almost always require a licensed cleaning service. Kitchens with more than one fixture line often run several grease traps at once, and each one needs its own service record.
Yes. Without regular maintenance, grease and solids build up until grease traps stop working the way they’re designed to, which leads to clogs, odor, and backups into the kitchen. Preventive maintenance on a set schedule costs far less than the cleanup after an overflow, and it keeps grease traps compliant with whatever the local health department requires.
Proper grease trap maintenance means checking grease levels on a consistent schedule, scheduling professional cleaning before the trap reaches capacity, and training kitchen staff to scrape food waste and excess oil into the trash rather than sending grease down sinks. Keeping a written log of service dates also helps with compliance with local health department requirements, and it gives a new manager or inspector a clear record of service needs going back years.
Requirements depend on the type of unit and the local wastewater authority. ReWa allows restaurant personnel to clean some smaller grease traps using approved removal and disposal methods. In-ground grease interceptors must be completely pumped by an approved transporter. Restaurant grease waste is regulated, but it should not automatically be described as hazardous waste.
Frequency of cleaning depends on the size of the trap and how much cooking oil the kitchen processes. Cleaning frequency depends on the type and size of the unit, the amount of FOG and solids collected, and the rules of the local wastewater authority. Small indoor traps may need weekly or more frequent attention. In ReWa’s service area, in-ground grease interceptors must be serviced at least quarterly unless a Commercial Pretreatment Inspector approves another schedule. The restaurant should follow the stricter of its measured accumulation rate and the required local schedule. Regular professional cleaning on that kind of schedule is what keeps grease out of wastewater lines and the sewer system your kitchen depends on, and it’s the single habit that keeps grease traps out of emergency territory. Well-run kitchens treat their grease traps the same way they treat any other piece of equipment on a maintenance log, not an afterthought.