Commercial kitchen grease traps are essential plumbing devices that capture fats, oils, grease, and food solids before they enter municipal sewer systems. When grease enters the sewer system, it cools, solidifies, and accumulates, causing blockages that lead to sanitary sewer overflows (SSOs), property damage, environmental contamination, and costly repairs. The EPA estimates that grease causes approximately 47% of all sewer line blockages in the United States, resulting in billions of dollars in annual maintenance costs. For commercial kitchens, proper grease trap maintenance is not optional — it is a regulatory requirement enforced by local municipalities, health departments, and environmental protection agencies. Failure to maintain grease traps can result in fines of $500-$10,000 per violation, depending on jurisdiction.
Types of Commercial Grease Traps
Commercial kitchens typically have one of three types of grease management systems. Passive grease interceptors (gravity grease traps) are small, under-sink units that use gravity separation to capture grease. These units typically hold 20-50 gallons and are installed directly under the sink or near the dishwasher. They are common in restaurants with limited kitchen space and must be cleaned every 1-4 weeks depending on usage. Automatic grease removal devices (GRDs / grease recovery devices) are mechanical units that automatically separate and remove grease from wastewater using heat, skimming, or centrifugal force. These reduce cleaning frequency to every 4-8 weeks and are increasingly popular in new construction. Large outdoor grease interceptors are concrete or fiberglass tanks buried outside the kitchen, typically holding 500-2,000 gallons. These serve large-volume kitchens such as hospitals, hotels, casinos, and institutional food service operations and require professional pumping every 30-90 days. Our commercial kitchen cleaning services include grease trap maintenance for all types of food service facilities.
Grease Trap Cleaning Procedures
Proper grease trap cleaning follows a systematic process. The cleaning crew should wear appropriate PPE, including gloves, aprons, safety glasses, and slip-resistant boots. The area around the grease trap should be protected with floor coverings. The trap lid is removed carefully and inspected for damage or deterioration. The depth of the grease layer, sludge layer, and clear water zone are measured and recorded. The grease layer should not exceed 25% of the total liquid depth; if it does, cleaning frequency must be increased. All contents are removed by pump truck or manual bailing into sealed containers for proper disposal. The trap interior is scraped and wiped down to remove residual grease and solids. All interior surfaces are inspected for cracks, corrosion, or damage. The inlet and outlet baffles are inspected and cleaned thoroughly.
After cleaning, the trap is refilled with clean water and checked for proper flow. The lid gasket is inspected and replaced if damaged. The lid is securely fastened. A cleaning log entry is completed with date, time, volumes removed, observations, and technician signature. Waste grease and solids must be disposed of at licensed facilities; illegal dumping of grease trap waste carries severe penalties. Used cooking oil should be collected separately in designated containers for recycling into biodiesel. Many municipalities now require grease trap cleaning reports to be submitted electronically through their environmental management systems.
Regulatory Compliance and Record Keeping
Municipalities across the United States have adopted Fats, Oils, and Grease (FOG) ordinances that mandate grease trap maintenance schedules, documentation requirements, and enforcement penalties. Most jurisdictions require commercial kitchens to maintain grease trap cleaning logs for at least three years. Cleaning logs should include the date of service, name of the service company, volume of waste removed, condition of the trap and baffles, any repairs or maintenance performed, and technician signature. Many jurisdictions require monthly cleaning unless testing demonstrates that less frequent cleaning is sufficient. Some municipalities require grease trap waste manifests documenting proper disposal. FOG compliance is verified during routine health department inspections and can result in citations, fines, or even permit revocation for non-compliance. For comprehensive kitchen exhaust cleaning and grease management, visit our kitchen exhaust and hood cleaning services.
Additional FAQs
How often should a commercial kitchen grease trap be cleaned? The standard recommendation is every 30 days for most commercial kitchens. High-volume operations (cafeterias serving over 500 meals/day, 24-hour restaurants) may need cleaning every 14-21 days. Low-volume operations (coffee shops, bars serving only snacks) may qualify for every 60-90 days with testing.
Can I clean my own grease trap? Self-cleaning is permitted in most jurisdictions, but the waste must be properly handled and disposed of at a licensed facility. Many municipalities require professional cleaning service for larger interceptors (500+ gallons) due to environmental and safety concerns.
What happens if I don’t clean my grease trap? Consequences include foul odors from decomposing grease, backups and overflows in your kitchen (health code violation), clogged sewer lines (expensive repair bills), municipal fines of $500-$10,000 per violation, and potential closure of your food service operation.
What is the difference between a grease trap and a grease interceptor? The terms are often used interchangeably. Technically, a grease trap is a smaller under-sink unit (under 50 gallons), while a grease interceptor is a larger in-ground or above-ground unit (50-2,000+ gallons). Both serve the same purpose of capturing FOG before it enters the sewer system.
Do I need to add bacteria or enzymes between cleanings? Bio-augmentation products (bacteria/enzyme treatments) can help break down grease between cleanings and reduce odors. They are not a substitute for physical cleaning but can extend the time between cleanings by 10-20% when used correctly.
About RBM Building Services: Since 1974, RBM has provided commercial janitorial, building maintenance, and comprehensive kitchen cleaning services across Utah, Arizona, Nevada, and Texas. Call 800.403.3564 or contact us.
