In the Water (Prevention and Control of Pollution) Cess Act, 1977(36 of 1977) (hereinafter referred to as the principal Act), in section 2, for clause (c), the following clause shall be substituted, namely:--
'(c) "industry" includes any operation or process, or treatment and disposal system, which consumes water or gives rise to sewage effluent or trade effluent, but does not include any hydel power unit;'.