Tennessee Spill: The Dredge Report
Scientific experts say that monitoring regimes put in place by the authority, as well as state and federal officials, may not be able to detect pulses of selenium, thanks to its odd chemistry, which may allow it to evade water monitoring.
Payne, who has a doctorate in soil science, told Sloan in an e-mail that the proposed water-monitoring scheme was of little use, since one of selenium's two relevant chemical forms is a toxic compound called selenite, which gets absorbed by secondary chemicals in coal ash and moves with the dredged ash, not in the water. Later, when exposed to more air, the selenite turns into selenate, another toxic form of selenium; it is not held by the secondary minerals and then moves on to take its toll on aquatic life. To make matters worse, according to Payne and others, the analytical methods used in the official monitoring efforts are simply not good enough to detect the trace amounts of selenium likely to be seen in the water. (The TVA said in an April 21 e-mail that official water-monitoring sites had detected no exceedances of selenium since dredging began. The statement also said the monitoring sites were designed to measure all forms of selenium.)
Payne, who has offered his consulting services to the TVA and state regulators, wants officials to understand why so many of the best-laid plans could be heading toward disaster. In the March 20 e-mail to Sloan, he questioned the TDEC's assumptions, pressed the agency to make its selenium data public and criticized Tennessee's water-quality standards as too permissive regardingselenium. He zeroed in on the state agency's pledge to follow up on fish tissue studies. The problem with fish tissue tests, he explained, is that selenium "bioaccumulates," inching its way into fish and animals over months and years, not days and weeks. If you find selenium in high concentrations in fish tissue, the theory goes, you're already in trouble. "[Fish tissue data] will not tell you how much more selenium may still come after you have finally detected that a threatening amount was there in the first place," he told Sloan. In a telephone interview, Payne said that the threat was hard to detect: "Selenium, by its nature and chemistry, will sneak up on us," Payne says. "It's like the frog in the pot of slowly heating water."
Among scientific experts, Payne is far from alone. "The folks in charge feel they don't have the luxury to consider other ways to clean the river out," said Joseph Skorupa, a biologist and selenium expert with the US Fish and Wildlife Service. "But they should understand that letting loose selenium is a momentous decision."
Back Door Bills
Shockingly, with toxic questions hanging over the dredging, the coal industry and the Tennessee legislature have been pushing to give selenium a free pass in the state's waterways. Two bills proposed in February--one in the Tennessee House and the other in the Senate--sought to deregulate selenate by exempting it from emission limits. Experts were dismayed. "There is absolutely no scientific reason for this," said Skorupa. "Who benefits from this?"
Still, Joe McCord, a Tennessee state representative and sponsor of the House bill, saw fit to include the selenate exemption in the proposed law. Reached on his cellphone April 9, McCord said he did not know about the exemption and that he would have to speak with experts before commenting. He added that the legislation had been suggested by the state's coal mining industry and that a subsequent amendment had actually struck the selenate provision from the bill. "People might think that the TVA is the ghost in the weeds on this one," he said. "But I haven't talked to a single person at TVA about this." He added: "We're just trying to bring Tennessee's standards in line with the scientifically proven standards of the EPA," he said. (The sponsor of the companion Senate bill, Senator Ken Yager, did not respond to interview requests.
But EPA standards are at the heart of the problem, according to Lemly. The EPA originally published recommended water-contamination standards for selenium in September 1987, but the agency never codified them. In December 2004, the EPA proposed revising the agency's recommended criteria to make them less strict. Those proposed revisions were "based on a review of new data on the toxicity of selenium to aquatic life," said Tulis of the EPA.
But Lemly and at least three current or former government scientists have publicly said that the EPA's "review of new data" was anything but solid. In fact, Lemly has accused EPA regulators of grossly misusing one of his studies to justify the change in the proposed selenium standards, which is favorable to selenium-polluting industries but does nothing to protect fish, wildlife and, ultimately, human health. "The EPA's proposed standards are grossly underprotective," he said.
"The EPA has fallen down on selenium," said Brian Paddock, a water-quality consultant who represents the Tennessee chapter of the Sierra Club. "But the Kingston spill means it is finally going to get its day. The EPA will be under pressure to do something."
Hard EPA regulations seem anything but imminent. Tulis said the agency expects to make available a revised draft of selenium standards this summer. Experts say they are hopeful that the revised standards will be more protective than current ones.