FARMINGTON – About 130 people gathered for the first day of a mining conference aimed at better understanding the environmental conditions facing the Animas and San Juan rivers.

Hosted by the New Mexico Water Resource Research Institute, various local and municipal agencies throughout three states, two Native American tribes and three Environmental Protection Agency regions attended sessions Tuesday at San Juan College.

“We wanted to bring together a diversity of experts and share information about ongoing monitoring, and discuss unanswered questions and fill in data gaps to fill those questions,” said New Mexico Environmental Department Chief Dennis McQuillan.

McQuillan said the two-day conference was structured to start from the emergency response to the Gold King Mine spill in August 2015, and then get into the “nitty gritty” of the geology, mining history and chemistry of the mining district north of Silverton.

“We wanted to cover all our bases,” he said.

On Aug. 5, EPA-contracted crew, while working on a remediation project on the Gold King Mine about 10 miles north of Silverton, accidentally breached the loose pile of dirt and rocks that covered the entrance to the long-inactive mine.

The event released an estimated 3 million gallons of mine wastewater, which contained heavy metals such as iron, cadmium, arsenic and lead.

The plume passed through the Animas and San Juan rivers, and eventually dumped into Lake Powell in Utah.

“What I saw was indescribable,” San Juan County manager Kim Carpenter said of the orange plume approaching New Mexico. “There was this beautiful clear crisp water, and what seemed to be chasing it was a wall of sludge.”

Experts for the better part of the day pored over data, both pre- and post-Gold King Mine spill. A major concern for researchers was the unknown amount of sediment left in the river. The remaining sediment, some believe, will be stirred with the coming spring runoff.

Robert Runkel with the U.S. Geological Survey said five new monitoring systems have been installed along the stretch of the Animas and San Juan rivers in New Mexico.

Runkel ran through a laundry list of studies conducted since the basin was first seriously characterized in the 1990s and early 2000s. He said the region’s naturally occurring mineralization makes any permanent fixes to the watershed a complicated issue.

“This is a long-term problem that involves sources contributing metals into the basin before the Gold King Mine spill, and sources contributing metals as we speak,” he said.

McQuillan said the federal agency will hold another conference next year and expects data collected from the year’s monitoring efforts will be available.

“We really want a watershed scale investigation and monitoring plan from the source in Silverton to Lake Powell,” he said.

jromeo@durangoherald.com

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