Pine River getting EPA attention
Velsicol site remediation efforts between EPA, EGLE span over two decades
For more than two decades remediation efforts of the U.S Environmental Protection Agency and the Michigan Department of Environment, Great Lakes and Energy have been focused on the former Velsicol Chemical plant site in St. Louis and the adjacent Pine
River.
More than $100 million was spent on a multi-year project to dredge and remove DDT from the portion of the river that runs along the north side of the 52-acre parcel, while millions more has been invested in cleaning up contaminants from the plant site and nearby residential neighborhood.
However, for the past few years areas downstream from the municipal dam in St. Louis have been getting more attention from both the EPA and EAGLE.
The agencies are now working on the third and fourth phases in areas referred to as Operable Units 3 and 4, according to EPA Community Involvement Coordinator Diane Russell.
OU 3 is approximately one mile downstream from the dam, while OU 4 is a mile in length where the Pine and Chippewa rivers converge.
This fall the EPA has been “evaluating options to clean up the sediment, floodplains and riverbank soils in OU 3,” Russell said.
“EPA expects to have a plan, including a public comment period, for a remedy to address Operable Unit 3 contamination next spring,” she added.
The work taking place in OU 4 is somewhat unique because the agencies are using activated carbon in its ecological study to see if it reduces contaminants such as DDT in the environment.
“Additional studies are necessary to understand if this technology can be carried forward as a possible remedy,” Russell said.
EPA researchers sampled earthworms from the test area, both before and after the carbon was applied.
The results showed an approximate 60 percent reduction in DDT concentrations in earthworms after the granular activated carbon charcoal was applied, Russell noted.
The location was selected based on previous remedial investigation activities, which included the collection and analysis of floodplain soils, a small mammal toxicological study and food web analysis.
Those studies indicated DDT and its metabolites, as well as PBB in the floodplain soils were adversely impacting ecological receptors including soil invertebrates
and organisms that feed on the invertebrates.
Other impacts found were reduced biomass and diversity, poor reproduction, and diminished abundance and abnormal behavior in robins and shrews.
The testing will help scientists understand how much the carbon reduces bioavailability of contaminants to animals, and if successful could reduce cleanup costs significantly, Russell said.
“The study will continue into next year when a determination will be made to either continue or stop the study,” she explained. “EPA and EGLE will also be doing additional floodplain sampling to evaluate how far contamination has traveled downstream within the Pine River.”
That data is expected to be available by February or March 2022.