This appeal from a judgment of the Supreme Court of Michigan draws in question the constitutional validity of certain provisions of Detroit's Smoke Abatement Code as applied to ships owned by the appellant and operated in interstate commerce.
The appellant is a Michigan corporation, engaged in the manufacture and sale of cement. It maintains a fleet of five vessels which it uses to transport cement from its mill in Alpena, Michigan, to distributing plants located in various states bordering the Great Lakes. Two of the ships, the S. S.C.rapo and the S. S. Boardman, are equipped with handfired Scotch marine boilers. While these vessels are docked for loading and unloading it is necessary, in order to operate deck machinery, to keep the boilers fired and to clean the fires periodically. When the fires are cleaned, the ship's boiler stacks emit smoke which in density and duration exceeds the maximum standards allowable under the Detroit Smoke Abatement Code. Structural alterations would be required in order to insure compliance with the Code.
Criminal proceedings were instituted in the Detroit Recorder's Court against the appellant and its agents for violations of the city law during periods when the vessels were docked at the Port of Detroit. The appellant brought an action in the State Circuit Court to enjoin the city from further prosecuting the pending litigation in the Recorder's Court, and from otherwise enforcing the smoke ordinance against its vessels, 'except where the emission of smoke is caused by the improper firing or the improper use of the equipment upon said vessels.' The Circuit Court refused to grant relief, and the Supreme Court of Michigan affirmed, 355 Mich. 227, 93 N.W.2d 888. An appeal was lodged here, and we noted probable jurisdiction, 361 U.S. 806, 80 S.Ct. 53, 4 L.Ed.2d 53.
In support of the claim that the ordinance cannot constitutionally be applied to appellant's ships, two basic arguments are advanced. First, it is asserted that since the vessels and their equipment, including their boilers, have been inspected, approved and licensed to operate in interstate commerce in accordance with a comprehensive system of regulation enacted by Congress, the City of Detroit may not legislate in such a way as, in effect, to impose additional or inconsistent standards. Secondly, the argument is made that even if Congress has not expressly pre-empted the field, the municipal ordinance (materially affects interstate commerce in matters where uniformity is necessary.' We have concluded that neither of these contentions can prevail, and that the Federal Constitution does not prohibit application to the appellant's vessels of the criminal provisions of the Detroit ordinance.
The ordinance was enacted for the manifest purpose of promoting the health and welfare of the city's inhabitants. Legislation designed to free from pollution the very air that people breathe clearly falls within the exercise of even the most traditional concept of what is compendiously known as the police power. In the exercise of that power, the states and their instrumentalities may act, in many areas of interstate commerce and maritime activities, concurrently with the federal government. Gibbons v. Ogden, 9 Wheat. 1, 6 L.Ed. 23; Cooley v. Board of Wardens of Port of Philadelphia, 12 How. 299, 13 L.Ed. 996; The Steamboat New York v. Rea, 18 How. 223, 15 L.Ed. 359; Morgan's Louisiana & T.R. & S.S.C.o. v. Louisiana Board of Health, 118 U.S. 455, 6 S.Ct. 1114, 30 L.Ed. 237; The Minnesota Rate Cases, Simpson v. Shepard, 230 U.S. 352, 33 S.Ct. 729, 57 L.Ed. 1511; Wilmington Transp. Co. v. R.R. Commission of California, 236 U.S. 151, 35 S.Ct. 276, 59 L.Ed. 508; Vandalia R.R. Co. v. Public Service Commission, 242 U.S. 255, 37 S.Ct. 93, 61 L.Ed. 276; Stewart & Co. v. Rivara, 274 U.S. 614, 47 S.Ct. 718, 71 L.Ed. 1234; Welch Co. v. State of New Hampshire, 306 U.S. 79, 59 S.Ct. 438, 83 L.Ed. 500.