(A) Grease interceptors shall be installed by users as required by Chapter 52 of this code. Grease interceptors shall be installed at the user’s expense, when such user operates a cooking establishment. Grease interceptors may also be required in non-cooking or cold dairy and frozen foodstuffs establishments and other industrial, commercial, or institutional establishments when they are deemed necessary by the HCDPU pretreatment staff for the proper handling of liquid wastes containing grease.
(B) No user shall allow wastewater discharge concentration from subject grease interceptor to exceed 200 milligrams per liter, as identified by EPA method 1664 or 150 milligrams per liter, as identified by EPA method 413.
(C) All grease interceptors shall be of a type, design, and capacity approved by the HCDPU Director or his or her designee and shall be readily and easily accessible for user cleaning and county inspection. No grease interceptor shall be less than 1,000 gallons total capacity unless otherwise approved by the Director or his or her designee. All grease traps should be designed and constructed outside of the confines of a building.
(D) All grease interceptors shall be subject to review, evaluation, and inspection by the pretreatment staff during normal working hours. Results of inspections will be made available to facility owner, leaseholder, or operator. The pretreatment staff may make recommendations for correction and improvement.
(E) Any user who is subject to this chapter that wishes to use a garbage disposal, food grinder, pulper, and the like will have these devices plumbed to the grease trap to prevent solids buildup in the collection lines.
(F) At user’s expense, all such grease interceptors shall be serviced and emptied of accumulated waste content as required in order to maintain minimum design capability or effective volume of the grease interceptor, but not less often than every 30 days. Any deviation from the 30-day schedule will only be allowed at the discretion of the HCDPU Director. A variance request should be applied for in writing to: HCDPU Pretreatment Unit, P.O. Box 1119, Lillington, NC 27546-1119. A variance will not result in a compromise of the integrity of the HCDPU collections system.
(G) Users who are required to pass water through a grease interceptor shall:
(1) Provide a minimum hydraulic retention time of 24 minutes at actual peak flow or 12 minutes at the calculated theoretical peak flow rate as predicted by the Uniform Plumbing Code fixture criteria, between the influent and effluent baffles with 20% of the total volume of the grease interceptor being allowed for sludge to settle and accumulate, identified hereafter as
SLUDGE POCKET;
(2) Remove any accumulated grease cap and sludge pocket as required, but at intervals of not longer than 30 days at the user’s expense. Grease interceptors shall be kept free of inorganic solid materials such as grit, rocks, gravel, sand, eating utensils, cigarettes, shells, towels, rags, and the like, which could settle into the sludge pocket and thereby reduce the effective volume of the grease interceptor;
(3) Accept the condition that if any skimmed or pumped wastes or other materials removed from the grease interceptor are treated in any fashion onsite and reintroduced back into the grease interceptor as an activity of and after said onsite treatment, the user shall be responsible for the attainment of established grease numerical limit consistent with and contained in division (B) above on all discharges of wastewater from said grease interceptor into the county sanitary sewer collection and treatment system;
(4) Operate the grease interceptor in a manner so as to maintain said device such that attainment of the grease limit is consistently achieved.
CONSISTENT shall mean any wastewater sample taken from said grease interceptor shall be subject to terms of numerical limit attainment described in division (B) above. If an establishment desires to use an alternative to an out-of-building grease interceptor, because of documented space restraints, the request for an alternative location shall contain the following information:
(a) Location of county sewer main and easement in relation to available exterior space outside building;
(b) Existing plumbing at or in a site that uses common plumbing for all services at that site; and
(c) Nature of the requested variance.
(5) Understand and agree that the use of chemical or biological additives as a grease degradation agent is not permitted;
(6) Understand and agree that the use of automatic grease removal systems is conditionally permissible, upon prior written approval by the pretreatment staff. Any establishment using this equipment shall operate the system in such a manner that attainment of the grease wastewater discharge limit as measured from the unit’s outlet is consistently achieved;
(7) Understand and agree that the pretreatment staff 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, modifications, or replacement of such traps. This review may also include the plumbing connections to and from the trap; and
(8) Understand and agree that a minimum of once per year, the pretreatment staff will conduct an inspection of the user’s grease interceptor. The pretreatment staff will coordinate with the user during regular monthly pumping to inspect the condition of the grease interceptor walls, bottom, top, cover, inlet and outlet pipes, and baffles.
(H) The user shall submit a grease trap service record form provided by the county to the pretreatment staff on the first day of each month. The user shall maintain a written record of trap maintenance for three years. All such records will be available for inspection by the county at all times.
(I) No non-grease laden sources are allowed to be connected to sewer lines intended for grease interceptor service.
(J) Except as provided herein, for a period of three months following adoption of this chapter, although installation and maintenance of grease interceptors will be required, no enforcement actions will be taken under this chapter for failure to achieve limits on grease discharges from said grease interceptors. If, at any time, an obstruction of a county sewer main(s) occurs or a sewer lift station problem occurs that causes a sewer overflow to the extent that an impact on the environment is realized and that said 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 a user’s establishment in the county’s sewer main(s) or lift station, the county will take appropriate enforcement actions and may hold the responsible user liable for costs related to service calls for sewer line blockages, line cleaning, line and pump repairs, fines, and the like including all labor, materials, and equipment.
(K) Access manholes, with a minimum diameter of 24 inches, shall be provided over each chamber and sanitary tee. The access manholes shall extend at least to finished grade and be designed and maintained to prevent water inflow and infiltration. The manholes shall also have readily removable covers to facilitate inspection, grease removal, and wastewater sampling activities.
(Ord. passed 7-16-2012) Penalty, see § 53.99