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Mining News: Red Dog tops EPA toxic release inventory Federal regulator’s annual report reflects scale of the world’s largest lead-zinc mine, not its outstanding environmental record Shane Lasley North of 60 Mining News
In its largely misunderstood and frequently misrepresented Toxic Release Inventory report, the U.S. Environmental Protection Agency ranked the Red Dog zinc mine in Northwest Alaska as the largest entity in the nation in releases of TRI reportable materials.
The EPA report, released in March 2009, reported that the world’s largest zinc mine released 533.4 million pounds of primarily zinc and lead compounds into the environment in 2007 (the latest figures available), down 81.9 million pounds from comparable discharges in 2006.
The EPA ranked Green Creek Mine second in Alaska in the toxic release inventory with 44.09 million pounds; the Fort Knox Mine, No. 3 with 3.6 million pounds; and the Pogo Mine, No. 4 with 1.96 million pounds. The Agrium fertilizer plant in Kenai was ranked No. 5 with 892,941 pounds in toxic releases.
“It is important to make this information available to Alaskans. The public wants to know what wastes are being generated or discharged in our state,” said Alaska Environmental Conservation Commissioner Larry Hartig. “It is also important to understand that most of the reported wastes are being managed in permitted, engineered facilities.”
TRI does not portray environmental quality Mining opponents often mistakenly cite Red Dog’s top ranking in the annual EPA report as an example of the detrimental effects of large-scale mining on Alaska’s environment.
The confusion and subsequent misrepresentation begins with the name of the report. Toxic release implies that the materials being reported are environmental pollution. In reality, more than 99 percent of chemicals reported in the Toxic Release Inventory are handled and stored legally.
“TRI data reflect only the amounts of the chemicals that have been disposed, released, or otherwise managed, not whether or to what degree the public has been exposed,” explained Brook Madrone, EPA Region 10 TRI Coordinator. “The large releases reported annually by metal mines in Alaska are due to the reporting of minerals that are listed as TRI chemicals – primarily zinc and lead – remaining in waste rock. This waste rock is disposed of in onsite impoundments. The more rock a mine processes, the more zinc and lead-containing waste rock is released. Teck Cominco’s Red Dog Mine, the world’s largest zinc mine, is no exception.”
About 99.95 percent, or 533.2 million tons, of TRI reportable materials at Red Dog are waste rock and tailings that state and federal permits allow the mine to safely manage.
“The total pounds of ‘releases’ do not at all reflect an accurate picture of Alaska’s environmental quality. The waste rock from Alaska mines is well engineered, contained and regulated by state and federal agencies,” said former DEC Commissioner Kurt Fredriksson. “Alaska’s environment continues to be clean, healthy and productive.”
Report reflects scale of mining The EPA’s annual report on toxic releases is not a commentary on Red Dog’s environmental record, but an observation that the world’s largest zinc mine moves incredibly large amounts of rock containing TRI reportable “toxins” such as zinc, lead and silver.
“Red Dog has the largest releases to land of trace metals that are listed as TRI toxics. The trace metals that are released are located primarily in the waste rock and in the tailings impoundment,” Madrone told Mining News. “Red Dog, being the largest zinc mine in the U.S., has the largest volume of toxic metals released to the rock piles and tailings impoundment. In addition, the concentration of these metals in the waste rock piles and impoundment is higher than in many other mines because of the quality of the ore.”
Meeting water standards improves creek quality While the minerals could be a cause of concern if released into the air or water in amounts above those permitted by federal and state environmental standards, this is not the case at Red Dog. More than 20 years after production startup in 1989, environmental protocols at the mine have reduced the mineralization of Red Dog Creek to levels lower than naturally existed before the mine was built.
Prior to mining, the enormous zinc-lead deposit leached large amounts of metals into the creek naturally. An independent analysis of the pre-mining water chemistry showed that about 250,000 pounds of zinc compounds flowed with natural runoff into Red Dog Creek annually. The naturally occurring high-metal content made the creek an unsuitable habitat for fish.
In 2007, Red Dog Mine released 559 pounds, or a fraction of 1 percent of the natural runoff, into the creek, according to EPA’s TRI data.
Since mining has begun at Red Dog, the same inhospitable areas of the creek now support Arctic Grayling and Dolly Varden.
In processing water discharged from the mine, dissolved metals are removed until extremely low levels are reached — water discharged from the mine contains fewer metals than the City of Anchorage’s residential drinking water. The improved water quality is due to changes to the creek’s hydrology and a state-of-the-art water collection and treatment system at the mine.
DEC technical engineer, Pete McGee added, “Alaska has very stringent water quality standards designed to protect public health and the environment. We ensure those standards are met by minimizing any discharges and ensuring adequate treatment of all wastes to prevent pollutants from impacting downstream users.”
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