1. The lid shall be secured to the body and easily accessible and removable with the use of common tools. No special tools shall be needed to remove the lid. HGI must be watertight and be constructed of materials not subject to excessive corrosion or decay. The HGI shall be coated so as to be resistant to corrosion. Refer to city of Gig Harbor Public Works Standards Chapter 5, List of Drawings for Specifications.

2. Baffle systems and all other internal pieces shall be removable to facilitate cleaning and replacement, but must be in place at all other times.

3. The lid shall cover the deep seal HGI. The deep seal HGI shall be constructed so as to eliminate the possibility of sewer gas entering the kitchen area.

4. HGIs and interceptors that are installed above ground must be equipped with an influent flow regulator and an effluent valve assembly that allows for sample collection.

1. The HGI may be set on the floor, partially recessed in the floor with top flush with the floor, or fully recessed below the floor to suit piping and structural conditions, as acceptable by the building and fire safety department of the city.

2. There shall be sufficient clearance for the removal of the HGI cover for cleaning and inspection.

3. The HGI shall not be installed in a waste line from a garbage grinder. Any garbage grinder waste shall bypass the HGI.

4. A suitable flow control fitting shall be installed ahead of the HGI in the waste line beyond the fixture and as close as possible to the underside of the lowest fixture. When wastes of two or more sinks or fixtures are combined to be used by one HGI, a single flow control fitting shall be used.

5. Air intake for flow control shall either terminate under the sink drain board as high as possible to prevent overflow, or shall terminate in a return bend at the same height and on the outside of the building. (The UPC requires devices to be readily accessible and in a visible location.)

6. To retain water and prevent siphoning, all HGIs shall have a vented waste, sized in accordance with the UPC.

7. With the approval of the fire and building safety department, one HGI may be used to serve multiple fixtures if the fixtures are located close together and the HGI is sized to meet the combined flow of all the fixtures.

1. Hydromechanical grease interceptors (HGIs) shall be serviced weekly or as needed on an individual basis. This will be determined by the amount of grease produced and a maximum measurement of no more than three inches accumulation on the top of the HGI or 25 percent of the total liquid volume is occupied by floating solids or sediment. In addition, discharge does not exceed the 100 mg/L limit. After accumulated grease and waste has been removed, the HGI shall be thoroughly inspected to make certain that inlet, outlet, and air relief ports are clear of obstructions.

2. Grease and other waste removed from the HGI shall not be introduced into any drain, sewer, or natural body of water. The waste shall be placed in proper containers for proper disposal. It shall not be mixed with “edible” grease. Grease and waste removed from an HGI shall not be disposed of in such a manner so as to become food for animals or humans.

3. The grease generator shall maintain adequate documentation that the HGI is appropriately cleaned and inspected as referenced in GHMC 13.30.111, Interceptor pumping and cleaning (GGI/HGI). Hydromechanical grease interceptor waste generators shall meet all applicable federal, state and local requirements regarding the accumulation, generation, and disposal of waste. (Ord. 1185 § 4, 2010; Ord. 1107 § 7, 2007; Ord. 1087 § 6, 2007).