for the legislative approval requirement to be applicable. See SDCL 34A-6-53, 34A-6-54. Also, the parties agree that the Big Stone plant accepts out-of-state waste, but nowhere do they specify how much of the plant’s 200,000-plus annual tons are composed of out-of-state waste. The fact that a small trickle of out-of-state waste would still be allowed to enter South Dakota after the Referendum would not save the Referendum if it otherwise had the practical effect of closing off South Dakota’s borders to out-of-state waste. See City of Philadelphia v. New Jersey, 437 U.S. 617, 618, 628, 98 S.Ct. 2531, 2532, 2587-38, 57 L.Ed.2d 475 (1978) (invalidating a New Jersey statute that prohibited the importation of most, but not all, out-of-state waste); Waste Sys. Corp., 985 F.2d at 1387-88 (<HOLDING>); Southeast Arkansas Landfill, Inc. v. Arkansas
holding that mere reference to the interlocal agreement in the citys ordinances even assuming the interlocal agreement impermissibly burdens interstate commerce by restricting the flow of solid waste is not enough to render those ordinances invalid holding that ordinances the effect of which was to remove 10400 annual tons of solid waste at 80 a ton from interstate commerce were discriminatory in practical effect holding that ordinance requiring all municipal solid waste generated within county to be delivered to a particular facility discriminated against interstate commerce holding that housing discrimination has a substantial effect on interstate commerce holding to the same effect