The US Environmental Protection Agency has issued a new directive that requires all mining companies to treat their wastewater to remove acid mine water, a source with knowledge of the change told ABC News.
The EPA issued the memo on Tuesday to mining companies and their subcontractors who conduct the treatment process at their mines.
In order to comply, mining companies must report the water that they use to treat wastewater to the EPA, the source said.
However, the memo does not include a list of how many companies currently use acid mine discharge to treat waste, and no specific requirements have been issued for how much acid mine wastewater must be treated.
An EPA spokeswoman told ABCNews.com the agency is still assessing how it would use the new guidelines, which it is drafting.
While some companies may continue to use acid discharge, others may not, the EPA said in a statement.
“The EPA is committed to working collaboratively with companies and other stakeholders to ensure that all mines comply with existing standards and meet the highest environmental safety standards,” the statement said.
“We will continue to work with the public to ensure all mining operations comply with all regulations, and that mining companies continue to do what is right for the environment.”
Environmental groups have pushed the EPA to regulate mining companies.
The US Chamber of Commerce has called for the EPA and the Department of Labor to regulate the industry.
The EPA, however, said it has not yet received the letter from the Chamber.
As it works through its review, the agency will update the memo, which will be shared with industry and government officials, the spokeswoman said.
The new rule, which requires mining companies with more than 1 million employees to use water from one of two types of treatment plants, was originally published in November 2016.
Earlier this year, the Department Of Labor and the EPA issued guidance calling for all mining industries to use one of three types of water treatment plants for wastewater treatment.
A new rule was published in March 2018 that expanded on the requirements to include new technologies that treat waste using a combination of chemical and mechanical techniques.
There are currently 14 chemical wastewater treatment plants in operation, including the two chemical ones that use acid-based water, the Energy Department’s Office of Waste Management said in its latest quarterly report.
All of the chemical plants that use the chemical wastewater are in the West.
At least one of the plants in the US are located in Pennsylvania, the Office of the Director of National Intelligence said.