Section 60(1) in Faridabad Complex Administration Building Rules, 1989
(1)Every drain shall :-(a)be of suitable size, and if it is intended for the conveyance of foul water shall have an internal diameter of not less than 100 millimetre;(b)be laid with a suitable fall and where practicable in a direct line. The standard gradient shall be 1 in 40 for a 100 millimetre drain and 1 in 60 for 150 millimetre drain. The maximum and minimum gradient shall respectively be 1 in 20 and 1 in 80 for a 100 millimetre drain and 1 in 40 and 1 in 140 respectively for 150 millimetre drain.
