KENNECOTT PROTECTING BIRDS AND WETLANDS OF THE GREAT SALT LAKE
by Harold Hough
When people think about Kennecott Copper and Utah, they think of the Bingham Canyon pit operation. The Bingham Canyon Mine has produced more copper than any mine in history -- about 18.1 million tons, so much that if it were turned into 14 gauge wire, it would reach from Jupiter to the Sun. The mine is 2¾ miles across at the top and ¾ of a mile deep. You could stack two Sears Towers on top of each other and still not reach the top of the mine. And, if you stretched out all the roads in the open pit mine, you'd have 500 miles of roadway -- enough to reach from Salt Lake City to Denver.
However as much engineering went into building and maintaining this pit, Kennecott engineers have been involved in engineering a lot of wetlands for the birds and wildlife of Utah. A century and a half of mining in and around Bingham Canyon has left a lot of environmental damage from an era when mines weren’t required to clean up after they stopped operations. Over the past two decades Kennecott has worked to clean up a contaminated water table, cleaned up and destroyed old mining facilities, and reclaimed acres of tailings. In the process, they have created a lot of wetlands.
One example is Smelter Slag Lagoon. The Smelter Slag Lagoon held excess process water supply and excess storm water from Kessler Canyon. Although it was no longer in use, Slag Lagoon sediment contained high concentrations of some heavy metals like arsenic. Although the concentrations were not a risk to humans, they did present a potential risk to sensitive wetland species.
In 2001 Kennecott drained the lagoon and moved the contaminated sediment to a toxic waste site. Workers then “terraformed” the prospective wetland and added 15 new islands. Then wetland flora was planted along the shore and a culvert was opened up to allow water for the Great Salt Lake to flood the lagoon. Now the site is a wildlife habitat.
Wetland development also means monitoring and cleaning up the groundwater. Studies showed that there was a serious water contamination problem near the wetlands on the south side of the Great Salt Lake. There were high selenium and arsenic levels present in groundwater beneath and downhill from the smelter and refinery. These contaminated waters were entering the wetlands.
Kennecott identified where the contaminated water was entering the wetlands and are now diverting it for industrial use. They also dug up contaminated soil and moved it to a toxic waste repository. After several years of pumping water from this area for process use, arsenic levels have declined dramatically.
Kennecott’s wetland development isn’t just limited to reclaiming old mining sites. It is also a technique to allow it to expand operations in ecologically sensitive areas. In fact, 3,670-acre Inland Sea Shorebird Reserve (ISSR) was developed by Kennecott. The wetland project came about when Kennecott needed to expand tailings impoundment near its smelter. Unfortunately, the only land available for the tailings was wetlands. Not only are they a source of bird biodiversity, the area was a stopping over point for migrating birds.
Kennecott talked to a wide range of environmentalists and experts at the EPA, Nature Conservancy, Utah Division of Wildlife Resources, US Fish and Wildlife Service, and the Army Corps of Engineers. To offset the loss of these wetlands, Kennecott bought about 3,989 acres of land near the south shore of Utah’s Great Salt Lake.
After cleaning up the area, Kennecott terraformed the land and secured alternative water sources to create and sustain the wetlands, dug ditches to bring the water to the area, and constructed shallow earthen dams to contain the water. The wetland and associated upland communities provide important feeding, staging (resting), and breeding habitats to migratory waterbirds. The Reserve now attracts migratory shorebirds and waterfowl and provides habitat for many other wildlife species. Overall, between 2 and 5 million shorebirds representing 200 different species visit the Great Salt Lake and its surrounding wetlands each year.
The project is now recognized as one of the most successful mitigation projects in the US. It was designated the Outstanding Environmental and Engineering Geologic Project by the Association of Engineering Geologists. In their commendation, they noted, “The procedures used and the success realized should serve as examples for future wetland mitigation planning.” In 2004, the site, along with the whole Gilbert Bay area was recognized by the National Audubon and BirdLife International as an Important Bird Area.
Wetland creation isn’t limited to correcting the problems of the past and the needs of the present. When the current tailing impoundment areas are no longer needed, Kennecott will return them to their original status as wetlands.
Kennecott has shown us that the mining industry can help make the surrounding ecosystem better than before. Rather than make the expansion of the copper operation a problem, the company has turned it into an environmental benefit. It’s proof that mining can have a positive impact on our environment.