Patagonia Area Resource Alliance

The Lead Queen Mine in Patagonia has been leaking acid runoff since 2014.

A mine that hasn’t operated in more than a hundred years continues to leak acid runoff in southern Arizona. The leak has been flowing out of the Lead Queen Mine in Patagonia since 2014. The Coronado National Forest has come up with a new plan to stop it.

The bright orange color of the runoff is caused by mineralization of iron-rich water, making the water acidic. It contains heavy metals, according to Heidi Schewel with the Coronado National Forest, 

She said the drainage only happens when it rains. Although past efforts have not been able to stop the flow, Schewel is confident the newest plan will work.

“What we're currently doing is plugging the main adit. It was a hydraulic plug. Then we're also putting additional filters in stream channel, should there be any discharge,” Schewel said.

Schewel said the forest service has not noticed any negative effects on the environment, but some local residents are skeptical.

Carolyn Shafer volunteers with the Patagonia Area Resource Alliance, a group that educates communities about the impact mining can have on the Patagonia Mountains, home to many bio-diverse and endangered species. She recounts a drainage in the past.

“It was literally acid. And the cattle are out there drinking it. It's it's affecting the plant life and everything else, it was a huge issue," Shafer said.

Shafer’s concerned that although the Forest Service’s plan may stop the flow, the acidic water trapped inside the mine may affect the groundwater, but Schewel assures that it shouldn’t affect the groundwater.

The Lead Queen Mine has not been operational since the early 1900s.