Eighteen head of cattle grazing near the abandoned Lanes Creek phosphate mine in Caribou County, Idaho, died earlier this month from acute selenium poisoning, the U.S. Department of Agriculture’s poisonous plant research lab in Logan, Utah, confirms.
Sheep and horses have died from selenium poisoning in the past after feeding on selenium-tainted vegetation in Southeast Idaho’s phosphate mining region, but cattle were thought to be less susceptible. Selenium is a toxic byproduct of phosphate that can leach and be absorbed by plants.
Kip Panter, the lab’s research leader, said the Bear Lake Grazing Association cattle were moved into the area on Aug. 2 and died about three days later. “It doesn’t take long. Acute selenium is very toxic. It affects the heart and lungs,” Panter said.
A range rider provided liver, kidney, and blood samples from the cattle. Panter said that the samples, which were analyzed by the Utah State Diagnostic Laboratory on the Utah State University campus, tested positive for high levels of selenium.
While water samples from a nearby creek were normal, Purple Aster showed 4,000 parts per million of selenium, which is relatively high, he continued, adding that lots of rain caused vegetation to grow more lush and high this season.
Dan Keetch of the Bear Lake Grazing Association did not return repeated phone messages regarding the cattle deaths. It was not clear who owned the cattle, totaling about 500 head.
Mining at Lanes Creek was begun in 1978 by the Alumet Partnership, which included National Steel Corp. – which filed for bankruptcy in 2002. Alumet sold the property to the Bear Lake Grazing Association in 1997. The J.R. Simplot Co. leases mineral rights, but has never mined there. It did process ore from the mine in the 1980s before mining was suspended later that decade.
Simplot spokesman David Cuoio stated: “The area where the 15 to 20 cattle died is not near any present or past Simplot phosphate mining operations.”
It was discovered in 1997 that horses and sheep grazing near Southeast Idaho phosphate mining operations were dying of selenium poisoning. As a result, Simplot, Monsanto, Agrium, FMC/Astaris, and Rhodia each spent $1 million to conduct an area-wide study in conjunction with the Idaho Department of Environmental Quality.
Several horses died near Agrium’s Mabey Canyon Mine in Caribou Canyon on pasture at the base of a mine dump. Hundreds of sheep also succumbed to selenium poisoning near Simplot’s Conda mine, not far from Soda Springs.
IDEQ Regional Administrator Bruce Olenick said his Pocatello office received a telephone call on Aug. 11 from Simplot, alerting it to the cattle deaths east of Monsanto’s South Rasmussen Ridge Mine and north of Simplot’s Smoky Canyon Mine. Simplot officials met with grazing association members on Aug. 10.
“Sheep are more susceptible. We always thought cows were more immune and had higher tolerances for selenium,” Olenick said, speculating the plants were eaten later in the year, when they had more time to mature and gain higher toxicity
IDEQ officials visited the Lanes Creek mine site on Aug. 13. Olenick said the private land had been reclaimed, describing it as a “big hump of vegetation,” but he said he understood cattle were not supposed to be grazing in the area.
Marv Hoyt, Idaho director of the Greater Yellowstone Coalition, an environmental group, said the recent cattle deaths are another indication of continued problems in the phosphate region. He said the kill should be a wakeup call for federal agencies and mining companies.
Forsaken mines that have not been cleaned up are polluting waterways, vegetation, and soil, Hoyt said. “With these old mines spread across the landscape, who knows what the real effects are on livestock and wildlife?” he asked.
Monsanto is seeking permission to open the Blackfoot Bridge Mine to replace its South Rasmussen Ridge Mine’s phosphate ore. Simplot is expanding its Smoky Canyon Mine.