Lee Wants Bioremediation in Housatonic River Vernal Pool Study
LEE, Mass. — The town has asked the U.S. Environmental Protection Agency and General Electric to include PCB bioremediation in its vernal pool study on the Housatonic River.
Lee officials are urging the EPA to require GE to add a bioremediation treatment arm to the vernal-pool study or provide the public with a clear explanation for why such testing is being excluded.
"This is exactly the kind of question EPA and GE should be asking before final remedy decisions are locked in," Select Board Chair Bob Jones said in a statement released to the press. "The town is not asking to slow the cleanup. We are asking EPA and GE to make the cleanup smarter, less destructive, and more protective over the long term."
An open house was held in Pittsfield earlier this summer for the Vernal Pool Pilot Study on Reach 5A of the Housatonic River, a five-mile stretch between the river's confluence and Lenox border.
EPA has required GE to conduct a Vernal Pool Pilot Study as part of the Housatonic River Rest of River remediation, comparing excavation and restoration with activated-carbon-based treatments, including a product called SediMite and powdered activated carbon, the town said.
Ten vernal pools will be cleaned of polychlorinated biphenyls in total, five with excavation and five with active carbon, and seven additional vernal pools will be monitored as controls. Construction will be complete around October, but the pools will be left to their natural processes and monitored with surveys and sampling for three years.
The Lee PCB Advisory Committee wrote a letter calling for the 21st-century approach it said could reduce long-term toxicity, avoid unnecessary destruction of sensitive habitats, and improve the effectiveness of the cleanup.
It states that Lee supports the study's purpose and agrees that EPA and GE must understand how cleanup activities affect sensitive vernal-pool ecosystems.
"The current pilot includes 10 treatment pools and seven control pools, while local officials understand that roughly 100 vernal pools may occur in the broader remediation corridor," the Aug. 27 letter reads.
"That makes the pilot study consequential: the methods tested now could shape how many sensitive wetlands are excavated, reconstructed, treated, or left with PCBs managed in place."
Vernal pools are seasonal wetlands that fill with water and then dry out, creating fish-free breeding habitat for amphibians, fairy shrimp, and other species. They are small but ecologically important, and their function depends on delicate conditions such as seasonal flooding, organic soils, leaf litter, woody debris, water chemistry, and surrounding forest habitat.
The town says the study leaves out a critical question: Can PCBs be biologically degraded or dechlorinated rather than simply buried, removed, or bound in place?
"Activated carbon can reduce PCB exposure by binding contaminants and lowering their bioavailability. But activated carbon does not destroy PCBs. It does not reduce total PCB mass. The Town believes EPA and GE should also test bioamended activated carbon or other PCB bioremediation approaches that could both reduce exposure and reduce long-term toxicity," the committee wrote.
"There is no scientific controversy: bioremediation is an important part of the PCB remediation toolkit. Bioremediation uses native microorganisms to break down or transform contaminants. In the case of PCBs, certain bacteria can remove chlorine atoms from highly chlorinated PCB compounds — a process known as dechlorination — potentially reducing toxicity over time when applied under appropriate conditions and making the compounds vulnerable to decomposition. In addition, the bioremediation materials are available from the same scientists the EPA is already working with for SediMite carbon, making it a simple addition to the process."
They want to know why EPA is not requiring GE to add a bacteria-rich solution, and are asking for EPA and GE to evaluate bioremediation in two ways: In situ within selected vernal-pool pilot areas to determine whether bioamended activated carbon can reduce PCB exposure while also degrading PCB compounds over time; and ex situ or in a contained setting, including dredged or excavated sediments placed in the proposed upland disposal facility, to determine whether PCB toxicity can be reduced after sediments are removed from the river corridor.
"If GE is already testing SediMite as a carbon delivery system, the obvious next question is why EPA is not also requiring a test of bioamended SediMite or equivalent PCB-degrading microbial technology," said Robert Heinzman, member of the Lee PCB Advisory Committee.
"A cleanup strategy that only moves or sequesters PCBs may reduce exposure, but it does not solve the long-term toxicity problem. We should be testing technologies that have been proven to actually degrade these molecules."
He added that this is a "missing opportunity" and the Housatonic River cleanup "should not be limited to 20th-century choices between digging, dumping, and binding PCBs in place."
The letter states that current research and field demonstrations are evaluating bioamended activated carbon —activated carbon paired with PCB-degrading microbial cultures, and it works, but to what degree depends on many variables unique to the contamination site, which is why testing makes sense.
The town wants the Housatonic River cleanup to evaluate these tools now, while pilot studies are rapidly being implemented this summer, and before broader vernal-pool and sediment-remediation decisions are finalized.
The Lee PCB Advisory Committee supports the town's review of, and public engagement with, the Housatonic River Rest of River PCB cleanup. The committee works to help ensure that the cleanup protects public health, ecological integrity, and the long-term interests of Lee residents.
Tags: PCBs, Rest of the River,
