City of Bismarck Grease Interceptor Requirements

1. All classes of food service establishments are required to submit the drainage plumbing plans to the pretreatment coordinator or designee for approval prior to obtaining a building permit.
2. The size, type and location of each grease interceptor (GI) shall be approved by the pretreatment coordinator before installation.
3. The location of the GI must be indicated on the Site Plan.
4. Grease interceptors shall be constructed in accordance with plumbing code. See Uniform Plumbing Code appendix H for GI design criteria.
5. Approved GI sizes range from 500 - 2,000 gallons in working capacity. The actual size will depend on the number of kitchen fixtures that are connected to the GI.
6. Baffle tees are required on the GI inlet, baffle wall and outlet.
7. Baffle tees must be visible through the 24-inch manhole cover for inspection and cleaning.
8. Venting of the GI from the GI cover is prohibited.
9. The GI concrete compressive strength must be greater than 4000 psi.
10. All GI must be designed and installed to withstand traffic loads.
11. Manhole covers shall be gastight in construction and have a minimum opening dimension of twenty-four (24) inches. Concrete covers are not acceptable. The access manholes shall extend at least to finished grade and be designed and maintained to prevent surface and ground water from entering the GI.
12. The manufacturer must certify that the GI meets three criteria: water-tightness, physical dimensions, and strength.
13. A two-way cleanout is required downstream of the GI.
14. An inspection of the GI is required by the Building and Inspections department before covering.