When required by the Industrial Waste Division of the Water Department, an approved oil interceptor shall be installed in the drainage systems of buildings, structures, parts of buildings, and premises of the following uses or occupancies:
- Commercial garages, auto repair shops, service stations, trucking docks, and any other place where gasoline or other flammable liquid with flash-point less than 90° F is dispensed or regularly used in connection with the work performed or processes employed;
- Dry cleaners or dyers using solvents;
- Paint, lacquer, or varnish factories;
- Printing in manufacturing plants.
Oil interceptors shall be constructed so as to be oil-tight and shall have easily removable watertight and gas-tight covers.
Every oil interceptor shall have a separate vent on the terminal end of the inlet piping and a fresh air inlet on the sewer side of the interceptor tank to relieve vapor. The size of the fresh air inlet shall not be less than 2 inches in size. The fresh air inlet shall be connected to the interceptor tank and extended to the outer air in accordance with Section P-503 or other location approved by the Department.
Construction of oil interceptors shall be one of the following:
- Reinforced concrete with the base, baffle wall and exterior walls not less than 6-inches thick; or
- 8-inch sewer brick parged to a smooth finish on the interior walls; or
- 8-inch 75% solid concrete block parged to a smooth finish on the interior walls; or
- Other materials as approved by the Department.
Adequate access to each compartment of the intercepting tank shall be provided by a minimum 18- inch manhole and removable cover. Manhole covers shall be cast iron or pre-cast reinforced concrete set into a retaining ring, and each cover shall weigh not less than 63 pounds. Manholes shall be brought up to grade and be water-tight and gas-tight.