BILLINGS — A company planning to build a large copper mine in central Montana will need to construct a pond for treated wastewater in order to comply with state water quality rules.
The Bozeman Daily Chronicle reports Sandfire Resources will build a 54 million gallon wastewater pond for the Black Butte mine north of White Sulphur Springs.
The company originally planned to send treated wastewater from mining through underground filters and then into the groundwater. State regulators said that would have left the mine unable to meet standards for nitrate pollution.
The company last month submitted a proposed addition to its discharge permit that includes the pond.
Montana Department of Environmental Quality spokeswoman Kristi Ponozzo says the change will delay a draft environmental study of the mine by a few months.