(A) Construction of interceptor. Grease interceptors shall be constructed in accordance with the city's standards and shall have a minimum of two compartments with fittings designed for grease retention. All grease removal devices or technologies shall be subject to the written approval of the city. The approval shall be based on demonstrated removal efficiencies of the proposed technology. The city's standard drawing for grease interceptors is shown in Appendix A.
(B) Access. Access to grease traps and grease interceptors shall be available at all times, to allow for their maintenance and inspection. Access to grease interceptors shall be provided by two manholes terminating one inch above finished grade with cast iron frame and cover.
(C) Load-bearing capacity. In areas where additional weight loads may exist, the grease interceptor shall be designed to have adequate load-bearing capacity (example: vehicular traffic in parking or driving areas).
(D) Inlet and outlet piping. Wastewater discharging to a grease trap or grease interceptor shall enter through the inlet pipe of the interceptor. Each grease interceptor shall have only one inlet and one outlet pipe.
(E) Interceptor sizing.
(1) The required size of a grease interceptor shall be approximated by using the city's grease interceptor sizing formula shown in Appendix B. Most grease interceptors will have a capacity of not less than 1,000 gallons nor exceed a capacity of 2,000 gallons. If the calculated capacity using the city's grease interceptor sizing formula exceeds 2,000 gallons, multiple units in series shall be installed. See Appendix B for example for formula.
(2) Grease interceptor designs represent minimum standards for normal usage. Installations with heavier usage require more stringent measures for which the user is responsible and shall pay the costs to provide additional measures if required by the city. The city reserves the right to evaluate interceptor sizing on an individual basis for facilities with special conditions, such as highly variable flows, high levels of grease discharge or other unusual situations that are not adequately addressed by the formula.
Editor's note:
Appendix A is available in the office of the City Clerk.