40 C.F.R. § 52.1030
Control strategy: Sulfur oxides
(a) The revision to Regulation 100.6 (Chapter 106) “Low Sulfur Fuel Regulation” for the Metropolitan Portland Air Quality Control Region, submitted by the Governor of Maine on August 25, 1977, is approved with the exception of paragraph 100.6.5(b) which allows the Commissioner of the Department of Environmental Protection to grant variances to Regulation 100.6.