Source: http://www.gazettextra.com, January 13, 2016
By: Elliot Hughes
JANESVILLE—General Motors expects to complete its own evaluation of a contaminated portion of the Rock River near its defunct Janesville plant by May, a spokesperson said Wednesday.
After that, the company will talk with the city of Janesville and the Wisconsin Department of Natural Resources—the lead agency in the matter—about how to fix the problem, said Sharon Basel, a GM spokesperson.
“We’re concerned,” she said Wednesday. “We take the matter very seriously and are acting immediately.”
Last week, a report by a consultant hired by the city concluded there are high concentrations of pollutants in the sediment of the Rock River near the old GM plant. The study was commissioned to determine how the river’s sediment would be affected if the city chooses to remove the Monterey Dam.
Linda Hanefeld, a supervisor for the DNR’s remediation program, reiterated Wednesday that the contamination poses no health risks to humans.
However, the city’s consultant, Madison-based Inter-Fluve, stated in its report that the sediment in question must be mechanically removed no matter what Janesville decides to do with the Monterey Dam.
Basel said GM has stayed in touch with the DNR about how it will conduct its evaluation and that GM will cooperate “with any cleanup scenarios that might be required.” Hanefeld also said GM has been cooperative.
Hanefeld said the DNR will not perform its own study on the area but will “work with the city and GM to look at the situation as a whole.”
Basel’s description of GM’s evaluation sounded similar to Inter-Fluve’s study. She said GM would hire an environmental engineering firm to take samples from the river in a “variety of locations,” analyze them and report the findings to all three parties.
Sampling could begin as soon as Feb. 1, Basel said.
“We’ve already begun, in terms of sending out requirements for engineering companies that we might hire,” she said.
Just how much GM is responsible, if at all, for the contamination hasn’t been determined yet. Hanefeld said the DNR has approached the city for information about any other party that might be culpable. A stormwater discharge point also sits near the site, she said.
The GM plant’s proximity to the contaminated area, Hanefeld said, is currently the only piece of evidence implicating the company.
The Inter-Fluve report said high concentrations of chromium, lead, mercury, zinc, cadmium, copper, arsenic and polycyclic aromatic hydrocarbons were found in sediment samples adjacent to the plant.
The contamination near GM—as well as other areas of the river sampled between the Racine Street and Center Avenue bridges—is strong enough to harm benthic aquatic life, or organisms that live at the sediment level of a body of water. But the report said the area by GM is “notably poorer,” and its sediment has a distinct odor.
The report said the GM area is the only one out of nine sampled areas where sediment must be removed. The excavation can be performed by temporarily walling off the area from the rest of the river to prevent sediment from being kicked up and drifting away, Hanefeld said.
The city originally planned to either repair or remove the Monterey Dam in 2016 or 2017, but that might be delayed because of the sediment problem, city officials said. The repair or removal has been mandated by the DNR, but Hanefeld said the department can be flexible on deadlines.