(A) Grease interceptors shall be installed by users, as required by § 52.024(C). 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 City Pretreatment/FOG Coordinator for the proper handling of liquid wastes containing grease.
(B) No user shall allow wastewater discharge concentration from subject grease interceptor to exceed 150 milligrams per liter, as identified by Chapter 52.
(C) All grease interceptors/traps shall be designed, installed and located in accordance with this chapter and local building codes. Specifications will allow for complete access to inspection, cleaning, maintenance and the like. All outdoor grease interceptors shall have a locking mechanism on all manhole covers, as deemed acceptable by the Pretreatment/FOG Coordinator. No grease interceptor shall be less than 1,000 gallons or greater than 1,500 gallons. When the required capacity exceeds 1,500 gallons, the Pretreatment/FOG Coordinator will look at all details of facility size and grease production, and may give special approval for a bigger trap if deemed necessary.
(D) All grease interceptors shall be subject to review, evaluation and inspection by the Pretreatment/FOG Coordinator during normal working hours. Results of inspections will be made available to facility owners, lease holders or operators. The Pretreatment/FOG Coordinator may make recommendations for correction and improvement.
(E) All such grease interceptors shall be serviced and emptied of accumulated waste content, as required in order to maintain minimum design capacity or effective volume of the grease interceptor, but not to exceed every 90 days. In-floor and under-the-counter grease traps shall be cleaned not less than every 30 days.
(F) 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 of 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 not to exceed 90 days for all outdoor grease interceptors and 30 days for all indoor units at the user’s expense. Grease interceptors shall be kept free of inorganic solid materials such as grit, rocks, sand, gravel, eating utensils, shells, cigarettes, 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 following conditions: If any skimmed or pumped wastes removed from the grease interceptor are treated in any fashion on-site and reintroduced back into the grease interceptor as an activity of and after said on-site treatment, the user shall be responsible for the attainment of the established grease numerical limit consistent with and contained in division (C) above on all discharges of wastewater from said grease interceptor into the city sanitary sewer collection and treatment system;
(4) Operate the grease interceptor in a manner so as to maintain the 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 (C) 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 city 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.
(5) Understand and agree that the use of chemicals, grease solvents, emulsifiers or thermal sources to temporarily dissolve fats, oils and grease in lieu of physical cleaning is not considered acceptable grease trap maintenance practice and is prohibited;
(6) Understand and agree that the use of enzymes and special bacteria formulations to reduce grease trap accumulations may be allowed in certain cases. A temporary approval may be given for a maximum of six months to prove their effectiveness. Pump out frequency may be reduced at the discretion of the Pretreatment/FOG Coordinator if products used prove to be effective. The burden of documenting these findings is the responsibility of the discharger and will require monthly service reports detailing the service provided and products used. If inspection by the pretreatment staff determines this treatment to be unsatisfactory, normal pumping frequency shall be resumed, as provided for elsewhere in this chapter;
(7) Understand and agree that garbage grinders shall not be discharged into a grease removal device. Special approval of garbage grinders by the Pretreatment/FOG Coordinator will be determined on a case by case basis and must discharge directly into the sewer system. It is not recommended that garbage grinders/disposals be used in commercial food establishments due to the amount of solid waste that is discharged into the sewer collection system. The debris creates sewer blockages and increased maintenance and repair of the wastewater plant and equipment;
(8) Dishwashers shall not discharge into under-the-counter grease traps or underground interceptors less than 1,500-gallon capacity. If the trap is sized to provide the manufacturer’s recommended detention time and the trap is located far enough away from the dishwasher to allow cooling of the water to less than 110°F, the Pretreatment/FOG Coordinator may grant an exception. A request shall be made to the Pretreatment/FOG Coordinator, and only after approval has been given can the dishwasher be installed accordingly. All wastewater from the dishwasher’s pre-rinse station must be discharged into the grease removal system;
(9) Understand and agree that the Pretreatment/FOG Coordinator 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;
(10) Understand and agree that the Pretreatment/FOG Coordinator will conduct facility inspections at a minimum of once every quarter or otherwise at his or her discretion. Every effort will be made to schedule inspections at a time that will be convenient to the management staff of said facility. The Pretreatment Staff will coordinate with the user during regular quarterly pumping to inspect the condition of the grease interceptor walls, bottom, top, cover, inlet and outlet pipes, and baffles; and
(11) Understand and agree that disposal of fryer oil into the city sewer system or stormwater system is specifically prohibited. The city strongly encourages the recycling of used cooking oil. Facility owners may contact the Pretreatment/FOG Coordinator for a list of renderers/haulers.
(G) The user shall submit a grease interceptor maintenance log form provided by the city to the Pretreatment/FOG Coordinator at the time of each inspection. The user shall maintain a written record of grease interceptor maintenance for a period of three years. All such records shall be made available for inspection by the Pretreatment/FOG Coordinator upon request. The following information must be maintained: receipt for job performed signed by the contractor, clean out date, owner or manager of the facility, name and license number of firm performing the clean out, disposal method and final destination of material removed.
(H) No non-grease laden sources are allowed to be connected to sewer lines intended for grease interceptor service.
(I) 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 pursued under this chapter for failure to achieve limits on grease discharges from said grease interceptors. If, during this three-month period, an obstruction of a city 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 the establishment in the city’s sewer main(s) or lift station, the city will take appropriate enforcement actions and may hold responsible the 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. Failure to pay all service related charges may also be grounds for sewer service discontinuance.
(J) Grease interceptor 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 9-13-2021) Penalty, see § 53.99