Under a proposed stipulated order concerning CAA violations at the Rush Island coal-fired power plant in Festus, Missouri, a settling CAA defendant must complete two primary mitigation projects, one supporting the distribution of stand-alone HEPA purifier devices to residential customers within Ameren’s service territory and another to promote the transition to electric school buses for schools in the St. Louis metropolitan and surrounding areas, and an additional project relating to the implementation of weatherization and energy efficiency upgrades in residential buildings if certain benchmarks are not met with the two primary projects.