(A) Purpose. The purpose of this section is to aid in the prevention of sanitary sewer blockages and overflows due to the accumulations of fats, oils and greases in the sanitary sewer from commercial establishments, particularly food preparation and food serving facilities, by requiring all food service facilities to install properly sized and maintained grease traps or interceptors to prevent excess fats, oils, and greases from entering the city’s collection system.
(B) Definitions. For the purpose of this section, the following definitions shall apply unless the context clearly indicated or required a different meaning.
FATS, OILS, and GREASES. Organic polar compounds derived from animal and/or plant sources that contain multiple carbon chain triglyceride molecules. These substances are measured using analytical test procedures established in 40 C.F.R. pt. 136. Fats, oils, and greases are collectively referred to herein as “greases.”
FOOD SERVICE FACILITIES. Those facilities primarily engaged in activities of preparing, serving, or making available for consumption by the public such as restaurant, commercial kitchen, grocery store, caterer, hotel, school, hospital, prison, correctional facility, and care institution. These FACILITIES use one or more of the following preparation activities: frying, baking, grilling, sautéing, rotisserie cooking, broiling, boiling, blanching, roasting, toasting, poaching, infrared heating, searing, barbecuing, and any other food preparation activity that produces a hot non-drinkable food product in or on a receptacle that requires washing.
GREASE INTERCEPTOR MINIMUM DESIGN CAPABILITY. The design features of a grease interceptor and its ability or volume to effectively intercept and retain greases from grease laden wastewaters discharge to the sanitary sewer.
GREASE TRAP or INTERCEPTOR. A device for separating and retaining greases and like compounds prior to entry into the sanitary sewer collection and treatment system. These devices also serve to remove and collect settleable solids from food service facilities prior to entry into the sanitary sewer. GREASE TRAPS and INTERCEPTORS are collectively referred to herein as GREASE INTERCEPTORS.
NON-COOKING FACILITIES. Those facilities primarily engaged in the preparation of precooked foodstuffs that do not include any form of cooking. These include cold dairy and frozen foodstuffs preparation and serving facilities.
NORTH CAROLINA PLUMBING CODE. Written guidelines, regulations and ordinances governing the plumbing criteria for type and use of plumbing systems in the State and its political subdivisions.
PUBLICLY OWNED TREATMENT WORKS or POTW. The collective wastewater treatment system owned and/or operated by the city, including all devices, systems and appurtenances thereto used in the collection, storage, treatment, recycling, distribution and reclamation of municipal sewage, industrial wastes of liquid nature, or other wastewater.
SANITARY SEWER. A pipe or conduit intended to carry wastewater or waterborne wastes from homes, businesses, and industries to the POTW. A sewer collection system.
USER. Any person, including those located outside the jurisdictional limits of the city, who contributes, or causes or permit the contribution of, wastewater into the POTW.
(C) Grease interceptors.
(1) All food service facilities shall install a minimum 1,000 gallon in ground grease interceptor, unless an alternative pretreatment method is approved by the city in accordance with division (D)(9). All grease interceptors shall be provided and maintained in continuously efficient operation at all times by and at the expense of the user.
(2) Existing food service facilities without a grease interceptor may be required by the city to install, operate and maintain a new grease interceptor that complies with the requirements of this section. If an overflow or failure of the sanitary sewer collection system to convey sewage can be attributed in part or in whole to an accumulation of grease from an existing facility without a grease interceptor, the city will require the facility to install a grease interceptor within 180 days of written notification. Any additional fixtures that are added to the existing facility and discharges a grease laden wastestream shall be plumbed into the interceptor and/or a new interceptor may be required.
(3) Exterior in ground grease interceptors shall be serviced and emptied of all waste content as required to maintain minimum design capability, but not less often than every 60 days. In floor and under the counter grease interceptors shall be cleaned not less often than weekly.
(4) In ground interceptors must have access manholes, minimum diameter of 24 inches shall be provided over influent and effluent chambers and sanitary tee. The access manholes shall extend at least to finished grade and shall be designed and maintained to prevent inflow and infiltration. The manhole also shall have readily movable covers to facilitate inspection, grease removal, and wastewater sampling activities.
(5) Minimum design criteria for grease interceptors shall be approved by the City Planning and Inspections Department in accordance with the NC Plumbing Code and provide for a minimum hydraulic retention time of 24 minutes at actual peak flow, between influent and effluent baffles with 20% of the volume of the grease interceptor being allowed for the sludge to settle and accumulate.
(6) Grease interceptors shall be kept free of inorganic materials such as rocks, grit, gravel, sand, eating utensils, cigarettes, shells, towels, rags, and the like, which could settle and reduce the effective volume of the grease interceptor.
(7) There shall be no reintroduction of wastewater back into the grease interceptor.
(8) The use of biological additives as a grease degradation agent is not permissible.
(9) A user may request to the Planning and Inspection department, an alternative to an in ground interceptor because of documented space constraints. The request shall contain the following information:
(a) Location of the city’s sewer main and easement in relation to available exterior space outside of the building;
(b) Existing plumbing at or in an establishment that uses common plumbing for all services; and
(c) Detailed list of all potential sources of grease at the subject premises.
(10) The POTW Director reserves the right to make determinations of grease interceptor adequacy and need, based on review of all relevant information regarding grease interceptor performance, facility site, and building plan review, and to require repairs to, or modification or replacement of such grease interceptors.
(11) Users are required to ensure that all material removed from grease interceptors is disposed of in a manner that complies with all federal, state and local statutes, rules, regulations, policies, and ordinances.
(12) The use of hot water flushing to clear the interceptor is prohibited.
(D) Grease interceptor inspections.
(1) The city will inspect an establishment’s grease interceptor and maintenance records at the city’s discretion. If problems are found during any such inspection, the user must take immediate corrective action as directed by the POTW Director.
(2) At inspection, grease cap and solids measurements will be performed. Grease accumulation shall not be greater than six inches at any point within the grease interceptor. Solids accumulation shall not be greater than 20% of the total water depth from the grease interceptor’s interior floor to the static working water level, at any point within the grease interceptor.
(E) Record keeping. User shall maintain a written record of all grease interceptor maintenance activities for a period of no less than three years. These records shall consist of clean out dates, the name of the owner or manager of the facility, and the name of the firm that performed the clean out. These records must be located on the premises and available for inspection during all business hours.
(F) Compliance monitoring. Any user that is subject to sampling by city staff will be accessed the cost for any analytical testing fees.
(Ord. passed 4-19-05; Am. Ord. passed 11-20-12)