MULTI-YEAR VELSICOL CLEANUP CONTINUES
DDT, PBB among chemical hazards being addressed in longtime remediation effort
Remediation of the former Velsicol Chemical Co. plant site in St. Louis will likely take several more years before it’s finished.
The facility closed in 1978 following the well-documented PBB disaster, then was completely demolished and buried on the now vacant and contaminated 52-acre parcel.
It’s estimated that more than $150 million has been spent on the cleanup thus far and that figure could reach a half-a-billion dollars by the time it’s complete.
On-site groundwater is contaminated with DDT, chlorobenzene, carbon tetrachloride and other chlorinated compounds. In addition, the soil contains PBB, copper, chromium, zinc and magnesium. For the past three years the U.S. Environmental Protection Agency and Michigan Department of Environment, Great Lakes and Energy have been using thermal treatment technology to heat the soil and groundwater on small sections of property, capture the contaminants and treat them on-site.
The agencies have also been collecting NAPL, or non-aqueous phase liquid, from extraction wells throughout the heating process.
Thus far about 135,000 pounds have been removed during phase 2 on a 1.5-acre parcel known as Area 2.
The NAPL consists of about 80 percent DDT, which was expected.
Although recovery has slowed, the heating process, which EPA officials had hoped would be completed by now, has been extended until at least mid-january, according to EPA Project Manager Tom Alcamo.
The first phase of Area 2 was completed last year with 183,000 pounds of contaminants and more than 4 million gallons of polluted groundwater removed.
The treatment costs about $800,000 a month and another $1.2 million has been built into the project to cover the additional time required, Alcamo told members of the Pine River Superfund Citizen Task Force during a recent meeting.
More than 11.5 million kilowatts of electrical energy was used to heat the soil in phase 1 of the Area 2 cleanup.
However, getting trucks to transport the contaminates, incinerator slots at an out-of-state landfill and shipping costs are proving to be a challenge for the agency, Alcamo noted.
Hazardous waste from most of the Velsicol projects is taken to a Clean Harbors incineration facility in Arkansas.
Additional work is already being planned for next year, according to EPA Community Involvement Coordinator Diane Russell.
The EPA and EGLE “continue to work on design studies for future cleanup activities that will take place at the former chemical plant site,” she said.
“EPA expects the next construction will begin next spring or summer in which approximately 100,000 tons of contaminated soil will be excavated and
disposed of off-site in an approved landfill. This work will likely continue for over two years.”
However, during that portion of the project strong odors due to the presence of petroleum products could become an issue.
Because volatile organic compounds will be part of
the excavation, air monitoring will take place, Alcamo said.
But the good news, he noted, is that dibromochloropropane, a pesticide banned by the EPA for most agricultural uses in 1979, is not present on the property.