Commercial vehicle repair garages and gasoline stations with grease racks or pits, storage garages, enclosed parking garages, fire stations, emergency vehicle garages, and all facilities which generate oil and/or flammable waste shall be provided with floor drains or trench drains connected to an approved gas and oil interceptor. Residential garages with floor drains shall have a gas and oil interceptor if they have four (4) or more vehicle bays or exceed 900 square feet in size.
(A) General Requirements.
(1) Gas and oil interceptors shall be of cast iron, steel, polyethylene, polymer concrete or equally durable fiberglass materials suitable for gas and oil fiberglass interceptors shall not be used for receiving any substance other than gas and oil. Poured concrete interceptors are prohibited.
(2) Each interceptor or basin shall be provided with a heavy metal cover which shall be bolted into place and made gas and watertight.
(3) Each interceptor and, if provided with separate compartments, each compartment and basin shall be provided with a vent of at least two 2”, which shall extend independently to the outer air. Two or more vents may be connected to a header which shall be 6” or higher than the lowest floor drain served.
(4) The inlet of the interceptor or the first basin shall be trapped except when floor drains are individually trapped.
(5) Floor drains above the level of the interceptor or basins shall connect to a separate stack vent.
(6) Interceptors must be constructed in accordance with the Illinois State Fire Marshal’s rules and regulations for underground storage tanks (41 Ill. Adm. Code 174), where applicable, and shall be maintained to prevent loss of gas, oil, etc. interceptors utilizing an automatic draw off feature must install a separate U.L. approved underground storage tank or storage tank integral with the interceptor.
(7) Minimum Dimension. Oil interceptors shall have a depth of at least 2’ below the invert of the discharge drain.
(8) Performance. The oil interceptor shall have at least a 12” water seal with a minimum 90 percent efficiency rating or have a minimum of an 18” water seal. Gas and oil in the effluent from the interceptor or triple basin shall not exceed the levels specified by the sewage treatment authority having jurisdiction, as promulgated by local ordinances and regulations.
(9) Trench drains shall be of cast iron, steel, polymer concrete or fiberglass material comparable to schedule 40 PVC. Poured concrete trench drains for gas/oil discharges are prohibited.
(B) Commercial Requirements. For all commercial facilities specified in this Section, a minimum of one (1) floor drain for each 500 square feet shall be installed. Where trench drains are used to carry wastes to the gas/oil interceptor, the trench drain shall either extend the entire length of the work (stall) area or shall be installed in each working stall. Continuous trench drains shall have a trapped and vented opening no less than every 40 lineal feet. Intermittent trench drains shall be treated as individual floor drains and shall meet the trap and venting requirements for floor drains. Floor drains for such areas shall be provided with an interceptor or a series of three (3) basins before discharging into the building drainage system.
(C) Sizing.
(1) Motor Vehicle Servicing. Interceptors are required for motor vehicle servicing areas. The minimum size interceptor shall be six (6) cubic feet (45 gallons) for the first 100 square feet of garage floor area plus one (1) cubic foot for each additional 100 square feet to be drained into the interceptor. (One (1) cubic foot equals seven and one-half (72 gallons.)
(2) The minimum size interceptor for all facilities, except those facilities required to conform to subsection (C)(1) of this Section, shall be six (6) cubic feet (45 gallons) for the first 500 square feet of floor area plus one (1) cubic foot per each additional 500 square feet to be drained into the interceptor.
(D) (1) Any user occupying and utilizing an existing structure having an operative gasoline and oil interceptor which met all applicable laws and standards at time of installation and which effectively collects gasoline and oil so as to prevent entry of same into the sanitary sewer may, upon request to and approval of the City Building Inspector, continue to use said existing interceptor until such approval shall be revoked for cause, including but not limited to inadequate maintenance, failure to maintain or clean, disrepair, change of standards, discharge of gas and oil into the sanitary sewer, inadequate capacity, or blockage within the sewer line or main.
(2) (a) A maintenance record shall be maintained by the user indicating maintenance and cleaning of the gas and oil interceptor. The record shall indicate each date and time of inspection and/or cleaning; each day and time of cleaning or maintenance; name of person performing cleaning or maintenance; name of person witnessing cleaning or maintenance; estimated volume of gas and oil and other materials removed; method of disposal of the gas and oil and other materials removed, and verification signed by the owner and manager of the user.
(b) The maintenance records shall be filed with the City Inspection Department on a regular and recurring basis not less often than quarterly; maintenance records shall be maintained for a 3-year period and shall be available for inspection by the City.
(c) The City Building Inspection or his authorized designee shall have such right of entry and inspection as may be necessary for the purpose of inspection, observation, measurement, sampling, and testing to determine compliance with this ordinance.
(Prior Code, Art. 16A, § IVA)