The following is a press release from the Pine River Superfund Citizen Task Force.
EPA Project Manager Tom Alcamo told members of the Pine River Superfund Citizen Task Force that the excess flow of a contaminant from the Velsicol Plant Site Superfund site means that they chose the correct area for thermal treatment.
“We put it in the right spot,” Alcamo told the membership in a Zoom call Wednesday evening.
Instead of the four tanker truckloads estimated, 12 truckloads have been drawn from as deep as 37 feet underground in the treatment area of about 1 ½ acres.
Scott Pratt, an employee from the EPA contractor, Jacobs, said the location is where the factory for the fire retardant PBB was located on the plant site.
PBB (poly-brominated biphenyl) was mistakenly bagged at Velsicol in St. Louis as magnesium oxide, an animal feed mineral supplement. When the PBB was mixed with the livestock feed at a Farm Bureau Services outlet in Climax, Michigan, the result was sick animals sent for slaughter, and the subsequent internal contamination of anyone in Michigan who purchased and consumed meat, milk, eggs, milk, butter and cheese from approximately 1973-1978.
The DNAPL (Dense Non-Aqueous Phase Liquid) being drawn up in the heating process contains heavy brominated amines, Alcamo said. While a gallon of water weighs eight pounds, a gallon of the DNAPL weighs 17 pounds.
The EPA has contracted with Cascade to heat the soil to boiling to bring up both contaminated vapors and contaminated liquids. Then each substance is run through its own treatment facility on site that destroys the contaminants. The toxic DNAPL, however, is trucked to an EPA-licensed commercial facility in Arkansas where it is incinerated.
During the past several weeks, the flow of vapors has ceased, and the liquid extraction has slowed. Alcamo said that the phase of “diminishing returns” has begun, which means the electricity providing the heat to the ground will soon be turned off.
Six soil borings recently taken in the worst areas of the small site “look very good, Alcamo said.
When Phase 1 of Area 2 has been completed, the operation will move to the location of the former DDT factory on the plant site to being Phase 2 of Area 2. Heating should begin there in the spring.
Alcamo said he will ask the federal government for money next summer to finish the design work for Potential Source Areas 1 and 2 that are located near M-46 and Watson Street. He expects excavation to begin in those areas in March 2022.
Other areas of the site will be treatment with a chemical oxidation process.