Section 104(5) in The Punjab Scheduled Roads and Controlled Areas Restriction of Unregulated Development Rules, 1965
(5)Every inlet other than a ventilating pipe to such drain shall be properly trapped by a suitable and efficient trap, and such trap shall be formed and fixed so as to be capable of maintaining a water seal of -(a)two inches where such inlet has an internal diameter of less than three inches;(b)three inches where such inlet has an internal diameter of less than three inches.
