A battle is brewing over how to best protect groundwater at mining sites around New Mexico.
The state Environment Department says the new rules it's proposing would be the most stringent of any copper producing state in the West, with new engineering requirements for handling left-over rock, leach piles, tanks and pipelines.
The proposed rules have the support of New Mexico's over 300 million dollar copper mining industry, but environmentalists say they would mark a huge step backward if approved by the state's Water Quality Control Commission.
The commission began what's expected to be a month-long hearing on Tuesday.
Environmentalists accuse the department of giving into the industry despite months of stakeholder meetings. Attorney General Gary King has also come out in opposition, saying the proposed rules would violate state water protection laws.