(1) Except in the case of a one-pipe system and a single-stack system, all waste water shall discharge into a trapped gully or grease-trap below the grating thereof and above the level of the water therein, which shall be connected to a sewer.

(2) No waste-pipe shall discharge into or connect with a gutter, hopper-head or pipe provided or used for the conveyance of rain-water or into a channel provided for the irrigation of a garden.