The Secretary may establish such emission control requirements, by rule, as in his or her judgment may be necessary to prevent, abate, or control air pollution. The requirements may be for the State as a whole or may vary from area to area, as may be appropriate to facilitate accomplishment of the purposes of this chapter, and in order to take necessary or desirable account of varying local conditions. (Added 1967, No. 310 (Adj. Sess.), § 8; amended 1971, No. 212 (Adj. Sess.), § 3.)