Public Works Commission

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Commercial Grease Trap Requirements

Section 31-43. Grease and Oil Removal

A) Grease and oil traps or other interceptors shall be provided at the User's expense, when such user operates an establishment preparing, processing or serving food and/or food products; except that such interceptors shall not be required for private living quarters or dwelling units. At a minimum, all food preparatory sinks, dishwashers, etc. shall be connected to the trap or interceptor. Any sink equipped with a waste-grinder or any plumbing fixture not associated with food preparation should not be connected to the trap or interceptor.

B) All interceptors shall be of a type and capacity accessible for cleaning and inspection. All such traps or interceptors shall be serviced and emptied of the waste content as required in order to maintain their minimum design capability to intercept oils and greases from the wastewater discharged to the public sewer, or to achieve compliance with the Oil and Grease limit of 250 mg/l (Section 31-46). For grease traps, the service shall be completed and documented at an interval not to exceed ninety (90) days. For under-the-sink interceptors, the service shall be completed and documented daily or at a frequency recommended by the manufacturer. If an under-the-sink interceptor is not serviced daily, it shall be the responsibility of the user to demonstrate compliance with the Oil and Grease limit.

C) Users who are required to pass water through a grease trap or similar interceptor will provide for a minimum detention period of twenty (20) minutes between the influent and effluent baffles with twenty (20) percent of the total volume of the grease trap or interceptor being allowed for a sludge pocket.

D) Where installed, all traps or interceptors shall be maintained by the User at his expense in continuously efficient operation at all times.

E) During trap maintenance, all inorganic and organic solids shall be removed from the sludge pocket. In addition, all floating material shall be skimmed from the trap or basin tank to avoid accumulation of scum covering the surface of the liquid. There shall be no reintroduction of the water removed from the trap either to the trap itself or to the sanitary sewer system without prior written approval from the PWC. The User shall be responsible for the removal and disposal by appropriate means of the captured material in accordance with local regulations.

F) The User shall maintain a written record on site of trap or interceptor maintenance for three (3) years. A copy of each service record shall be sent to the PWC Pretreatment Program office no later than fifteen (15) days after the end of the month during which the maintenance occurred.