In the case of Train, Administrator, Environmental Protection Agency v. City of New York et al., 1974, the Supreme Court ruled in favor of Russell E. Train, who was then serving as administrator for the Environmental Protection Agency (EPA). The issue at hand was whether or not the EPA had overstepped its authority by implementing a system to control air pollution that differed from what Congress had outlined in amendments to the Clean Air Act. Several states and cities argued that this action exceeded statutory limits on agency power. However, upon review, it was determined that while Congress did specify certain requirements for state implementation plans regarding air quality standards under Section 110(a)(2) of the Clean Air Act Amendments of 1970; they also granted discretion to EPA administrators under Section 110(c) to promulgate regulations necessary for enforcement if a state fails to submit an adequate plan within specified deadlines. Thusly allowing them flexibility in how these standards were enforced and maintained.

In the dissenting opinion for TRAIN, ADMINISTRATOR, ENVIRONMENTAL PROTECTION AGENCY v. CITY OF NEW YORK et al., 1974, Justice William O. Douglas argued that the Environmental Protection Agency (EPA) did not have the authority to suspend or delay implementation of certain pollution control standards as it had done. He believed that Congress intended for these standards to be implemented without delay when they passed the Clean Air Act Amendments in 1970 and therefore disagreed with his colleagues' interpretation of this legislation which allowed EPA such discretion. Douglas also expressed concern about potential harm caused by delaying enforcement of environmental regulations and emphasized a need for strict adherence to legislative mandates aimed at protecting public health and welfare from air pollution hazards.