Revoked a rule that prevented coal companies from dumping mining debris into local streams.
Withdrew a proposed rule aimed at reducing pollutants, including air pollution, at sewage treatment plants.
Withdrew a proposed rule requiring groundwater protections for certain uranium mines.
Weakened federal rules regulating the disposal and storage of coal ash waste from power plants. (A second phase of this rollback is still under way.)
Proposed rolling back protections for certain tributaries and wetlands that the Obama administration wanted covered by the Clean Water Act.
Delayed by two years an E.P.A. rule regulating limits on toxic discharge, which can include mercury, from power plants into public waterways.
Ordered the E.P.A. to re-evaluate a section of the Clean Water Act and related guidance that allows states to reject or delay federal projects – including pipelines and other fossil fuel facilities – if they don't meet local water quality goals.