A lawsuit introduced Wednesday is challenging the CuMo mining project above the Treasure Valley. The plaintiffs it would damage the area’s native plants and water supply.

In March, the U.S. Forest Service approved the CuMo mining project’s exploratory drilling operation to establish an open pit mine.

Three months later, environmental legal defense organization Advocates for the West has filed a lawsuit against the agency. It says the Forest Service isn’t taking necessary precautions to protect Idaho’s native Sacajawea bitterroot plant from drilling activity.

But John Robison is the Public Lands and Wildlife director for Idaho Conservation League, says he’s most concerned about water quality.

“The Boise River is the lifeblood of our community, and anything that happens up in their headwaters that could affect our quality of life, our drinking water, our recreation, our local economic opportunities really should be of concern to everyone,” said Robison.

The drilling and open pit mine would be next to Grimes Creek , a major watershed that feeds into the Boise River. Copper pit mining is known to use corrosive sulfuric acid to dissolve copper compounds.

Project leader Idaho Copper didn’t immediately respond to comment. On its website , the company says “The CuMo Project will not adversely affect the water quality in the Boise River.”

The U.S. Forest Service released a report last year agreeing with Idaho Copper’s assessment, saying the project had “no significant impact” on the mining area.

Idaho Copper says liquid acid drainage will be held by a tailing storage dam. But Robison says open pit mines are notorious for contaminating water sources.