EPA proposed to repeal amendments to the 2024 Mercury and Air Toxics Standards (MATS). This action would release all covered facilities from the more stringent filterable particulate matter (PM) emission standard for coal-fired EGUs, the tighter mercury standard for lignite-fired EGUs, and the requirement to use PM Continuous Emissions Monitoring Systems (CEMS). It would revert back to 2012 standards for the industry.