Par. 1. - Every building from which, in the opinion of the superintendent of sewers, grease may be discharged in such quantity as to clog or injure the sewer, shall have a special grease trap satisfactory to the superintendent of sewers. Every building in which gasolene, naphtha or other inflammable compounds are used for business purposes shall be provided with a special trap, satisfactory to the superintendent of sewers, so designed as to prevent the passage of such material into the sewer, and ventilated with a separate pipe rising to a point four feet above the roof. All non-siphon traps shall be of a type approved by the commissioner. The waste pipe of every wash stand for vehicles shall be provided with a sand box of sufficient capacity.

Par. 2. - The waste pipe from the sink of every hotel, eating house, restaurant or other public cooking establishment, shall be connected to a grease trap of sufficient size, easily accessible to open and clean, placed as near as practicable to the fixtures that it serves.

Section 124. Roof Leaders and Surface Drains

Par. 1. - Rain water leaders when connected with house drains shall be suitably trapped and, within the proposed surface drainage area, shall not be connected at the top of the stack, nor extended down through the interior of the building, except by special permit from the commissioner. Wherever a surface drain is installed in a cellar or basement, it shall be provided with a deep seal trap and back water valve. Drain pipes from fixtures in cellars and basements liable to back flow from a sewer shall be supplied with back water valves.