On or about September and October 2007, Generac imported into Illinois 998 large spark-ignition (SI) nonroad engines. Although, the engines were imported for use stationary emergency generators, Generac failed to affixed the required stationary engine label to each of the engines. This constituted 998 violations of Sections 203(a) and 213(d) of the Clean Air Act,42 U.S.C. §§ 7522(a) and 7547(d), and the implementing large spark-ignition (SI) nonroad engine regulations, 40 C.F.R. Part 1048 (SI Nonroad Regulations).