The Red Dog Mine in northwest Alaska is major source of chemical releases, according to a new federal report.
State officials said the Environmental Protection Agency report released Tuesday is not an accurate representation of releases, Alaska Public Media reported .
The EPA's 2017 Toxics Release Inventory National Analysis includes a look at the EPA's Region 10, which covers Alaska and the Pacific Northwest.
Alexandra Dunn with the EPA said 86 percent of released chemicals reported in that region were from the Red Dog Mine. The agency said total releases from the mine increased 43 percent between 2016 and 2017, the latest figures available.
Dunn said onsite land disposal accounted for almost all of the Red Dog Mine's 2017 releases.
State Department of Environmental Conservation officials said the data doesn't reflect the exposure risk to the public because the discharges were properly disposed of.
"If you were able to take away or consider that the materials are permitted for discharge and disposed of in a responsible manner, Alaska would rank amongst the lowest in the nation," said Allan Nakanishi with the DEC. "So we really want to communicate that these discharges are regulated and safely disposed of."
DEC Commissioner Jason Brune said in a statement that "characterizing such releases as toxic is disingenuous at best."
Mine officials said the numbers reported to the EPA come from permitted operations. The movement of mined rock heading for the waste facility requires reporting, said Wayne Hall, a spokesman for mine owner Teck Resources, located in Canada.
Dunn noted that a chemical release doesn't equate to a risk, and said the data shouldn't be looked at in a vacuum.
"Where is the release going? Is it going into the air, into the water, and/or into the land? And of course we need to look at the extent and effectiveness of safeguards that are in place to prevent the movement of chemicals," she said.
Given the increase in chemical releases, the report is concerning, said Pamela Miller with Alaska Community Action on Toxics.
"Just the fact that this is being brought to the surface, it is a waste rock pile. It is subject to environmental exposure and erosion downwind and downstream from this waste rock facility, is still a primary concern, and I don't think there's any guarantee that this material is actually contained on-site," Miller said.
Hall said the increase stemmed from a greater concentration of the mineral galena in the mined rock. More ore was mined as well, he said.