How often must a Phoenix restaurant pump its grease interceptor, and what records must it keep?

Section 28-15 requires interceptors to be "maintained by the user in continuously effective operating condition at all times." At minimum that means periodic removal of all accumulated grease, lint, oil, sand, sludge, solids, wastewater and other materials, thorough cleaning of the interior, and necessary repairs to internal structures. The code then sets the schedule:

• Hydromechanical interceptors (grease traps): "must fully pump out and clean the interceptor at a frequency of not less than once every 30 days unless granted a variance by the Director. No hydromechanical interceptor may be allowed to go more than 90 days without maintenance."
• Gravity interceptors at food service establishments: pumped out and cleaned "not less than once every three months" unless the Director grants a variance.
• All gravity interceptors: a full cleaning once fats, oils and solids pass 25 percent of capacity, and at least once every 12 months unless the Director grants a variance. The 12-month floor is what reaches gravity interceptors at laundries, car washes and other non-food businesses.
• No chemical shortcuts: enzymes, bacteria, solvents and emulsifiers may not be used in lieu of physical cleaning, and a pumper may not put removed contents back into the interceptor.
• Records: they must be available at the facility or site for a minimum of three years from the date created and be made available to the Director on request. The code says they cover all cleaning, the volume of waste removed, device capacity, waste disposal, repair, replacement and maintenance.

The city's FOG manual restates the schedule in kitchen terms. It adds that a licensed pumper must do the cleaning, that the interceptor must be left completely empty, and that a new kitchen should watch how fast grease builds during its first months with its pumper or an Environmental Services inspector and adjust the interval. The manual says the interceptor "may need to be pumped more frequently." Maintenance is "the sole responsibility of the user, or in the case of multiple user interceptors, the property owner."

• User: the business that operates the kitchen. For an interceptor shared by several tenants, the manual makes the property owner responsible.
• Variance: permission from the Director for a different interval. Neither the code nor the manual promises one.
• Records: the manual counts pumping invoices from third-party contractors as maintenance records.

Any user of a grease trap or gravity interceptor in the City of Phoenix. The 30-day and 90-day trap rule covers every hydromechanical user, and the three-month rule is written for food service establishments. Section 28-12 also reaches laundries, service stations, auto repair shops, car washes and commissaries when the Director requires an interceptor, and those gravity interceptors fall under the 25 percent and 12-month rules.

• A taqueria pumps its trap once a quarter because nothing smells. Without a variance, quarterly does not meet the 30-day standard and can run past the 90-day cap.
• A restaurant's gravity interceptor is pumped every three months on the dot, but the kitchen fries a lot. The schedule is a minimum. If the inspector finds grease and solids over 25 percent, the interceptor needs a full cleaning sooner.
• A strip center shares one interceptor among four tenants. The property owner is responsible, so the owner needs the pumping invoices, not just each tenant.
• The same taqueria switches to an enzyme product to stretch its pumping schedule. The answer flips: the manual prohibits enzymes and bacteria used to dissolve grease, and the pumping frequency still applies.

1. 1Find your device type (trap or gravity interceptor) and put its next pump date on the calendar.
2. 2Book a licensed pumper and ask for a written invoice every visit.
3. 3Keep a folder at the restaurant with every invoice and log for the last three years.
4. 4Watch the first months of a new kitchen and shorten the interval if grease builds fast.
5. 5If you want a longer interval, ask the Director for a variance before you stretch the schedule. Questions about interceptors go to the Water Services Environmental Services Division, which schedules interceptor plan review appointments at 602-495-0278.

• "Quarterly is the rule for everything." That is the food service gravity interceptor minimum. Traps are every 30 days, and gravity interceptors at non-food businesses have a 12-month floor.
• "My pumper keeps the records." The code says the records must be available at the facility or site.
• "Pumping out the liquid is enough." The interceptor must be completely emptied and cleaned, and the removed material may not go back in.