All pretreatment facilities to prevent the discharge of fat waste, oil, or grease shall be installed, maintained and operated by the discharger at his own expense. The installation shall be kept in continuous operation at all times, and shall be maintained to provide efficient operation. Cleaning of a gravity grease interceptor (GGI) grease removal system must be performed by a service contractor qualified to perform such cleaning. Trap-style hydromechanical grease interceptors (HGIs) may be maintained by the establishment as long as all the proper procedures for the cleaning and disposing of all waste materials are done in the proper manner.

At a minimum, gravity grease interceptors shall be cleaned at least once every 90 days and hydromechanical grease interceptors cleaned at least biweekly. These required frequencies may be extended with the approval of the director of public works. Grease interceptors must be cleaned whenever the combined thickness of the floating greases and settled solids is equal to, or greater than, 25 percent of the total liquid depth in the interceptor. When cleaned, a gravity grease interceptor must be completely pumped out, all solids removed, solidified grease scraped from the interior and the structure and all internal plumbing inspected for damage and corrosion. The GRS shall be refilled with cold water prior to being placed back into operation. If repairs are required, they shall be performed within 30 days.

When cleaned, the hydromechanical grease interceptor must have surface grease and oil removed, settled solids removed, all walls scraped, removable parts removed and cleaned, be inspected for damage and corrosion, and be properly reassembled. If repairs are required, they shall be performed within 30 days.

Material that is removed in the process of cleaning a grease removal system shall not be discharged back into the interceptor, any part of the POTW, any private sewer, any drainage piping or storm sewer system. All materials removed shall be handled and disposed of in accordance with federal, state, county and local rules and regulations. Grease removal devices (GRDs) that automatically, mechanically remove nonpetroleum fats, oils and greases from the interceptor shall be maintained in accordance with the manufacturers’ guidelines.

If a failure to maintain settling tanks, grit traps, grease interceptors, or oil/water separators or any other grease pretreatment facility results in partial or complete blockage of the building sewer or other parts of the POTW, adversely affects the treatment or transmission capabilities of the POTW, or requires excessive maintenance by the city, the discharger responsible for the facilities shall be subject to the remedies, including enforcement and penalties, in Article III of this chapter. (Ord. 3220 § 2, 2016; Ord. 2742 § 2, 2008; Ord. 2031 § 9, 1995; Ord. 1945 § 4, 1993; Ord. 1705, 1989. Formerly 14.60.358)