Section 46(4) in Punjab Urban Planning and Development Building Rules, 2018
(4)Waste water pipes. - A waste water pipe from a bath, sink (not being a slope sink), bidet or lavatory basin and pipe for carrying water directly shall -(i)not discharge as to cause dampness in the walls or the foundation of a building; and(ii)if it discharges into a drain, be disconnected from the drain by a trapped gully with a suitable grating above the level of the water in the trap.
