Greater PCB concentrations found at Western Middle School
GREENWICH — New tests have found PCBs in the ground at Western Middle School in much greater concentrations than have been discovered previously.
Soil samples in one area of the fields contain concentrations of the carcinogen above the Connecticut Significant Environmental Hazard threshold of 15 mg per kilogram of soil. In previous tests at the school, PCB concentrations were only found as high as 5.03 mg/kg.
The results were released by Greenwich school officials on Friday afternoon.
The state Department of Energy and Environmental Protection defines Significant Environmental Hazard conditions for soil to be: “Polluted soil present within two feet of the surface with the potential to pose a short-term direct contact risk to humans.”
Langan Engineering, the town’s environmental consultant, is in the process of conducting additional testing at Western, on order from the state, to determine the delineation, or boundaries of the contaminated area at the school.
Langan officials said they have not yet determined the extent of PCB contamination.
“We have analyzed 48 samples to date. Based on sample results received, we know that additional sample collection in the field will be required, in an attempt to achieve compliance/delineation,” said Langan Vice President Jamie Barr.
Many more soil samples will need to be analyzed, he said.
The fields at Western have been closed since the end of August when elevated levels of PCBs and other contaminants were found there.
It’s possible that portions of the Western fields will be reopened after delineation has been determined, but not until then.
Also Friday, officials announced that Langan has determined the delineation of lead and chlordane contamination at the fields. According to the update, 75 to 100 cubic yards of soil must be excavated and disposed of off-site due to lead and chlordane contamination.
“We are in the process of putting together an estimate for these costs, which will be completed once we have a full understanding of the remediation needs of the site,” said Barr.
Lead concentrations for the end-point samples ranged from 259 mg/kg to 542 mg/kg. Lead was previously found in concentrations ranging from 7.74 to 1,640 mg/kg at the fields.
For lead, the site-safety standard set by Langan is 606 mg/kg. The state requires remediation when lead is found in excess of 6,000 mg/kg.
Langan’s borings found chlordane concentrations of up to 0.0369 mg/kg for the end-point samples. The state residential direct exposure criteria for chlordane is 0.49 mg/kg.
Langan is not conducting further arsenic testing because arsenic concentrations previously identified on the property were within acceptable EPA limits.