Settlement with Tractor Supply Company Inc. and Tractor Supply Company of Texas L.P. resolves allegations that the companies imported and sold more than 28,000 ATVs, off-highway motorcycles, and engines that did not comply with federal Clean Air Act certification and emission information labeling requirements. Under settlement, company will implement compliance plan to prevent future violations and mitigation projects to reduce air pollution. Company will also pay $775,000 civil penalty.