Most of the actions are reconsiderations of existing policies, including regulations on power plants, the oil and gas industry, vehicles and wastewater. Standards for mercury, pollutants, greenhouse gas emissions and air quality are also being reviewed.

WASHINGTON (AP) — In what he called the “most consequential day of deregulation in American history,” the head of the Environmental Protection Agency announced a series of actions Wednesday to roll back landmark environmental regulations, including rules on pollution from coal-fired power plants, climate change and electric vehicles.