Dist. Ct. did not err in dismissing as untimely plaintiffs’ action alleging that defendant-power company violated section 7475(a) of Clean Air Act by failing to seek construction permit for installation of “best available control technology” (BART) for each pollutant subject to said Act when modifying five of its coal-fired power plants. Applicable limitations for said action is five years, and plaintiffs did not bring instant lawsuit until 10 to 15 years had passed after modifications had been completed. Ct. rejected plaintiffs’ claim that limitations period did not apply under either continuing violation or continuing-injury theories based on plaintiff’s argument that each day of power plant operation without instant (BART) permit constituted separate violation of section 7475(a). As such, once limitations period had expired, defendant was entitled to proceed as if it possessed all required construction permits.