Section 3(2) in The Environment (Protection) Rules, 1986
(2)Notwithstanding anything contained in sub-rule (1), the Central Board or a State Board may specify more stringent standards from those provided in [Schedules I to IV] [ Substituted by G.S.R. 422(E), dated 19.5.1993 (w.e.f. 19.5.1993).] in respect of any specific industry, operation or process depending upon the quality of the recipient system and after recording reasons, therefor, in writing.
