922.12 GREASE INTERCEPTOR MAINTENANCE REQUIREMENTS.
(a) New and existing Grease Interceptors shall be maintained in efficient operating condition by periodic removal of the full content of the interceptor which includes wastewater, accumulated FOG, floating materials, sludge and solids from interceptor walls, baffles and floor.
(b) All existing and newly installed grease interceptors shall be maintained in a manner consistent with a maintenance frequency approved by the WWTP official pursuant to this section.
(c) No FOG that has accumulated in a grease interceptor shall be allowed to pass into any sewer lateral, sewer system, storm drain, or public right of way during maintenance activities.
(d) The maintenance frequency for all Food Service Establishments with a grease interceptor shall be determined by one of the following methods as determined by the City of Aurora.
(1) Grease interceptors shall be fully pumped out and cleaned at a frequency such that the combined FOG and solids accumulation does not exceed 25% of the total design hydraulic depth of the grease interceptor. This is to ensure that the minimum hydraulic retention time and required available hydraulic volume is maintained to effectively intercept and retain FOG discharged to the sewer system.
(2) All Food Service Establishments with a Grease Interceptor shall fully pump and clean out their grease interceptor not less than every 90 days.
(3) If a FSE wishes to clean its GI less often than the minimum specified in this Chapter (every 90 days), a waiver request is required. The owner/operator of a Food Service Establishment may submit a request to the WWTP official requesting a change in the maintenance frequency at any time. The Food Service Establishment has the burden of responsibility to demonstrate that the requested change in frequency reflects actual operating conditions based on the average FOG accumulation over time and meets the requirements described in this Chapter, and that it is in full compliance with the conditions of this Chapter. Upon determination by the WWTP official that the requested revision is justified, the maintenance frequency will be reduced and documented in a letter to the owner/operator. Upon determination that the requested revision is not justified, the FSE will be required to continue maintaining the GI at the specified frequency.
(4) If the grease interceptor, at any time, contains FOG and solids accumulation that does not meet the requirements described in Section 922.12
(d)(1), the Food Service Establishment shall be required to have the grease interceptor serviced within five (5) business days such that all fats, oils, grease, sludge, and other materials are completely removed from the grease interceptor. If it is determined that an overflow or blockage situation exists, the interceptor shall be serviced immediately. If deemed necessary, a WWTP official may also increase the maintenance frequency of the grease interceptor from the current frequency.
(e) Wastewater, accumulated FOG, floating materials, sludge/solids, and other materials removed from the grease interceptor shall be properly disposed off site by waste haulers in accordance with federal, state and/or local laws.
(f) Food waste disposal units shall not be connected to or discharged into any grease interceptor.