EPA rolls back mercury emission standards and ends Good Neighbor interstate pollution rule

EPA Administrator Lee Zeldin announced on February 20, 2026, a sweeping package of 31 deregulatory actions described as the largest single-day deregulatory event in U.S. history, including repeal of the 2024 Mercury and Air Toxics Standards amendments and termination of the Good Neighbor Plan governing interstate air pollution. The MATS repeal allowed coal-fired power plants to emit more than twice the previous mercury limit and removed mandatory particulate matter continuous emissions monitoring. The Good Neighbor Plan's end released downwind states from enforceable emissions reduction requirements.