Environmental Protection Agency staff are being told not to enforce violations against oil and gas companies, CNN reported this week.

Agency officials gave the order verbally to EPA staff in the Midwest – home to refineries, chemical plants, and a legacy of industrial contamination – multiple EPA sources told the outlet.

The Trump Administration has made it a priority to unwind the country’s environmental regulations, including a rule last week proposing to repeal pollution standards for existing coal- and new natural gas-fired powerplants.

The move is part of what Trump EPA Administrator Lee Zeldin in March called the “biggest deregulatory action in U.S. history,” with plans to slash rules on oil and gas wastewater, chemical disaster rules, and regulations on mercury emissions from coal plants.