HELENA (AP) — State environmental regulators have given Tintina Resources permission to drill four wells to assess the groundwater in the area of its proposed copper mine in central Montana.

The Vancouver, British Columbia-based company plans to begin the 30-day test at the site of the Black Butte Copper Mine as soon as possible, said Jerry Zieg, vice president of exploration for Tintina Alaska Exploration.

The proposed mine is north of White Sulphur Springs and near Sheep Creek, a tributary of the scenic and popular Smith River. The state holds a lottery each year for permits to float a 59-mile stretch of the river.

Tintina plans to drill three pumping wells and a monitoring well at depths of 200 to 400 feet to learn where the groundwater starts, how deep it goes and how quickly it recharges, said Lisa Peterson, a spokeswoman with the Department of Environmental Quality. 

The agency is requiring Tintina to store the pumped water in a tank rather than a lined pond, as the company had proposed. The water contains some arsenic and will be sprayed over a 12-acre area at a rate at which the water will be used by plants or evaporate before it reaches the groundwater.

Tintina said the amount of arsenic that will end up on the ground will be well below the level allowed by the federal Environmental Protection Agency.