Possible Dredging at TVA Fly Ash Spill Could Create Health RisksMar 9, 2009 | Parker Waichman LLP
Selenium, while necessary to humans and animals, could result in catastrophic outcomes on fish when released at high levels, according to scientists, noted the Tennessean, which reported that the TVA received approval from the Tennessee Department of Environment and Conservation (TDEC) for its Phase I dredging plan. A. Dennis Lemly, a research biologist at Wake Forest University and an expert on the effects of selenium from coal ash on fish, told the Tennessean that dredging could release toxic levels of selenium into the water.
Lemly told the Tennessean that, “The hazard occurs because selenium bio-accumulates in the aquatic food chain." What happens, said Lemly, is that the metal builds up in fish eggs, causing spine, fin, and other deformities as well as infertility. "They're essentially poisoned at birth," Lemly said. Looking at fish contaminated by the spill just after the accident revealed a variety of health problems including, said the Tennessean, signs of stress, scale abrasions, and discolored gills, and ash filling the bellies of catfish.
Bryce Payne, a soil scientist from Pennsylvania who informed investigators from the Senate Environment and Public Works Committee about selenium dangers linked to the TVA spill, suggested turning the waste into concrete before removal, said the Tennessean. Payne explained that exposing selenium to air or aerated water would release the metal downstream noting that, "It could kill fish in the Emory, the Clinch, and maybe down the Tennessee. To do the dredging (TVA's) way could be a disaster. You might have a dead river."
Payne’s suggestion involves injecting the ash with cement because concrete made from fly ash and cement sets quickly and once set, could be broken and removed from the water and then stored safely with the toxins trapped within the concrete. "The trick is doing it under water," Payne told the Tennessean adding that, "It's not going to be a simple matter, but there's the possibility the river will come out of this cleaner than before."
The spill caused much area destruction of property and the environment, including trapping felled trees and debris in the sludge. Also, said the Tennessean, there are some areas in which the ash sludge is 30 feet thick. Payne’s plan would be ineffective in these areas.
Phase I of the dredging plan involves clearing the Emory River channel; however, significant work is required to clear the river bed which had prior contamination with mercury and PCBs. TVA remains unclear about how long the cleanup will take and continues to investigate the cause of the spill, which followed a dike break. Of note, the massive spill was not TVA’s first accident and its records confirmed that a1984 annual inspection report indicated that an interior dike failed and that exterior walls were not meant for additional loads, according to an earlier report by the Knoxville Biz. At that time, additional studies were recommended; it is unclear if such studies occurred. Also, in 1984, a dike failure resulted in dredged material spilling into a then-dredged area as a result of a problem with an interior wall. In 2003, another accident, which dumped water and fly ash on to Swan Pond Road occurred.