Study: Sheboygan River PCB levels remain high
While Sheboygan's river and harbor have seen a significant drop in a cancer-causing chemical thanks to a just-completed multimillion-dollar river clean-up effort, current levels in sediment and fish still pose "unacceptable risks," according to a recent federal review.
However, Sheboygan leaders and other government officials say such results were expected this soon after cleanup was completed and could take years to hit targets for environmental improvements. What's more, the report is entirely separate from a project designed to lift the impairment designation for the river and harbor.
The second five-year review of the superfund site found significant decreases in the river's PCB levels, an obsolete industrial compound that is a probable carcinogen, in the upper Sheboygan River and harbor, but has yet to meet its target levels for sediment and fish tissue.
"This report found the remedy at the Sheboygan Harbor and River site is not protective of human health and the environment," the report's summary reads. "While the remedy has been implemented in accordance with the requirements of the decision documents and design specifications, current levels of PCBs in fish tissue and sediments exceed the remedial action objectives and corresponding cleanup numbers, resulting in unacceptable risks to human and ecological receptors."
The area was originally contaminated as a result of PCB use at a die-cast plant in Sheboygan Falls run by Tecumsah Products Co. The company hired a separate company to assume liability and lead the dredging and cleanup efforts in the area.
The feds want to eventually lower the level of PCBs in sediment to 0.5 parts per million, which is equivalent to a half a drop in 10 gallons of water. Samples taken for the upper river area show that PCB levels decreased by 60 percent in five years due to dredging, but still hover slightly above the 0.5 ppm goal. The upper river dredging work was completed in 2007.
The PCB levels in the fish depend on where the samples were taken and whether they were sport fish or bottom-feeders. While PCB levels decreased from 2008 for most sport fish, most adult carp had levels that were not "significantly different" from 2008. The lower river levels were also significantly reduced compared to upper and middle river PCB levels.
Rick Nagle, the assistant regional counsel for the EPA, said that the Superfund site is on a 30-year track to reach safe levels for PCB concentration, though he notes that they expect to meet that mark earlier. All the report says is that "we're not there yet," Nagle said.
Nagle added that fish would likely be the last to see decreased levels of PCB, since there are likely fish that have spent a good deal of time in the lake and are likely to have accumulated higher levels of PCB over time.
"It'll take time for the sediments to get to their target and then there will be a lag for the fish to get in their clean environment," Nagle said. "There are probably some fish that have been down there for a long time; until they're caught or go out of the lake somewhere, they'll be in that system."
The report may cause confusion for those who have followed the area's cleanup efforts. In 2013, work was completed on cleanup and dredging as part of the Great Lakes Restoration Initiative.
That project saw more than $50 million in federal funds and several million in state and local funds go toward dredging operations in the lower river and harbor. As a result, the Wisconsin Department of Natural Resources has drafted a report to the feds asking them to remove one of nine designations of "impairment" to beneficial use of the river. The report will be submitted after the close of the public comment period at the end of the month.
The five-year plan, however, makes clear that it is not reviewing the impact of that project or any undertaken by the Great Lakes National Program Office.
Sheboygan Mayor Mike Vandersteen, when asked to comment on the report, said he believed it is too soon to determine whether the dredging efforts have had the desired impact.
"I think it's probably too early to see the change, because it takes awhile for the wildlife to absorb that," Vandersteen said.
Nagle agreed, saying there'll have to wait for longer term data before they can assess whether there's a definite decrease in PCB levels.
Reach Jason Smathers at 920-453-5167.