77 Ill. Adm. Code 890.510
Grease Interceptor Requirements
Section 890
Section 890.510Â Grease
Interceptor Requirements
Plumbing systems for
institutions or commercial establishments in which grease, fats, culinary oils
or similar waste products from kitchens or food processing areas are wasted, or
in which grease, fats or culinary oils are wasted in connection with utensil,
vat, dish or floor cleaning processes shall include grease interceptors. All
waste lines and drains carrying grease, fats or culinary oil in these
establishments shall be directed to one or more interceptors. (See Appendix E.Illustrations
A and B.)
a)Â Â Â Â Â Â Â Â All required grease interceptors shall comply with the
following:
1)        Material and Covers. Grease interceptors shall be constructed
of durable, corrosion-resistant materials and shall have water-tight covers
securely fastened in place.
2)        Minimum Size. A grease interceptor installed on the same
floor as the fixture shall have one-half the liquid-holding capacity of the
fixture. A grease interceptor located on a floor below the fixture shall have 60
percent of the liquid-holding capacity of the fixture. To determine the liquid-holding
capacity in gallons of a plumbing fixture, the length is multiplied by the
width by the height in inches and divided by 231. Where two or more sinks or
receptacles are connected to an interceptor the liquid holding capacity shall
be based on the combined volume of the fixtures served.
3)Â Â Â Â Â Â Â Â No grease interceptor shall receive the discharge from a food
waste disposal.
4)Â Â Â Â Â Â Â Â The flow rate of the interceptor shall be sufficient to handle
the maximum demand of the connected system.
5)Â Â Â Â Â Â Â Â All interceptors shall be installed in an accessible location
to permit the convenient removal of the lid and internal contents.
6)Â Â Â Â Â Â Â Â All interceptors shall be designed and installed with proper
venting so that they do not become air bound. (See Appendix E.Illustration C.)
b)        Prohibited Type. Water cooled grease interceptors are
prohibited.