Section 294(1)(d) in The Calcutta Municipal Corporation Act, 1980
(d)to provide a closed drain in substitution of an open drain or to provide such other appliance or thing either newly or in substitution of any existing appliance or thing or to provide both a closed drain and such other appliance or thing in substitution of the existing open drain and other appliance or thing which is or is likely to be injurious to health;