Section 266(1) in Gauhati Municipal Corporation Act, 1971
(1)No person other than a licensed plumber shall execute any work pertaining to water supply, drainage and sewerage disposal as described in this part and no person shall permit any such work to be executed except by a licensed plumber:Provided that if, in the opinion of the Commissioner the work is of a trivial nature, he may grant permission in writing for the execution of such work by a person other than a licensed plumber.