The stability of heavy metals on the bed of Lake Coeur d’Alene is still an open question, according to a critique published in journal Northwest Science.
The critique’s author, Tom Pederson, was hired by Hecla Mining Co. and others in the industry to review a controversial 1993 study by U.S. Geological Service scientist Art Horowitz. That study suggested that metals trapped on the lake bottom could eventually pose a health hazard.
“They were concerned that the truth, or the proper interpretation, was not being advanced,” said Pederson, a marine geochemist and professor of oceanography at the University of British Columbia.
The way Horowitz views it, the mining companies just didn’t like what he had to say.
“The fact that the information is disturbing to one or more individuals … is unfortunate,” Horowitz said.
The scientific dispute mirrors the highly charged political debate over how dirty the Coeur d’Alene Basin is, and who should bear the responsibility for cleaning it up. The federal government in March sued several mining companies for environmental damage in the Coeur d’Alene basin.
Both scientists suspect the other’s work is driven by politics.
Horowitz’s 1993 government-funded study concluded that the heavy metal mining waste stored on the lake bottom - including lead and zinc - could be released into the water if the lake is robbed of too much oxygen. Once released into the water, the metals could pose a health hazard.
The results were widely publicized, along with Horowitz’s comment that “the metals I’ve seen in this lake are among the highest I’ve ever seen.”
The study has been used to justify proposals to dredge the lake, which is estimated to cost hundreds of millions of dollars.
Pederson, however, said such proposals are premature.
He called the 1993 study flawed because Horowitz and fellow scientists failed to follow proper procedures to evaluate the form the metals are stored in.
“The techniques were improperly applied; the samples were not collected in the right way,” Pederson said Thursday. “All this was compounded by improperly interpreting the data.”
When contacted at his Atlanta office, Horowitz said, “That’s his opinion.”
Both scientists were offended by the implication that their science was tainted by politics.
“I resent the fact that I’m being shot because I’m the messenger,” said Horowitz, who conducted the 1993 study with USGS and Idaho Division of Environmental Quality money.
Phillip Cernera of the Coeur d’Alene Tribe, which has called for dredging the lake and is a party in the federal lawsuit against mining companies, painted Pederson’s review as another political move by the mining industry.
“They’re going to hire their hitmen to attack everything we’ve done in every way, shape or form,” he said. “You know, it’s war. It’s war.”
Pederson defended his own work, saying, “I have nothing I’m championing here except the truth.”
While mining industry representative Holly Houston said Pederson’s critique “proves” that “the best place for those metals is at the bottom of the lake,” Pederson himself concludes that nothing has been proven.