A single spike in PCBs in the air halted demolition of a former GE building in Pittsfield. Here’s what to know | Central Berkshires

PITTSFIELD — The U.S. Environmental Protection Agency has ordered General Electric Co. to halt demolition of Building 12 after a single air sample showed PCB levels above the regulatory “action level” for the chemical.

The sample was taken July 11-12 at one of eight monitoring stations near the site; it was the only one of 72 taken over the past six months that exceeded EPA health and safety limits. The Pittsfield Economic Development Authority reported the incident on July 25, when the test results were released, the EPA said.

“The excess does not pose a threat to public health,” the EPA said Thursday. “These action levels are very conservative, and furthermore, this monitor was not located next to public areas.

The agency further stated: “Monitoring sites located on the northern perimeter of PEDA and GE properties, and adjacent to residential properties, were below health-based notification and action levels.”

According to the EPA, the agency and its Massachusetts counterpart, the state Department of Environmental Protection, believe the increase in PCBs in the air came from the nearby demolition of Building 12, where the chemical was used to make power transformers for decades.

The sample, which measured 0.2324 parts per million, was taken near the property line separating GE from Site 9, a parcel of industrial property that GE transferred to PEDA under a 2000 consent decree.

The “notification level” at which the agency must be informed of the presence of PCBs in the air at the GE/Housatonic site is 0.05 ppm. The “action level” at which work must stop is 0.10 ppm. The recent finding is the only one that exceeded the notification level, let alone the action level.

General Electric is demolishing Building 12 and Building 14, also known as the “tank shop,” but retaining the property as well as Building 100, the massive manufacturing building that sprawls between the buildings.

The EPA said work at Building 12 remains suspended until several conditions are met and the results of a new round of testing are known. PEDA’s backfilling of Site 9, which had also been suspended, resumed on July 29.

Site 9 is a 16.5-acre parcel at the corner of Tyler Street and Woodlawn Avenue, where the “teenager” buildings at the Power Transformers Campus once stood (all of the buildings at the massive plant were numbered). The parcel is being prepared with a $10.8 million investment for future development, including foundation removal, utility conduits and landscaping.

The EPA said PEDA has several air monitors installed at its Site 9 construction site. Typically, PCB air quality testing has a turnaround time of 12 to 13 days.

The Massachusetts Department of Environmental Protection reviewed the data provided by PEDA, “and agreed with EPA that there is a strong likelihood that the source of the PCBs was not PEDA’s activities, but rather the source of airborne PCBs emanating from GE property associated with building demolition activities.”

General Electric proposed the following conditions for resuming work at Building 12:

• Conduct a round of PCB air sampling at five sampling locations and a recently added sixth location on PEDA property, not far from where the action level results mentioned above were recorded.

• Resume demolition work if the most recent tests show that all sampling locations are below the action level of 0.1 ppm.

• Conduct weekly PCB air sampling at these six locations for at least four weeks, or until results show four consecutive weeks of results below the action level.

• Employ additional engineering controls, such as reducing the size of on-site debris piles and keeping them farther from the property line.

The EPA approved GE’s proposal with the following additional conditions:

• GE can continue work if test results are above the notification level and below the action level, but the company must assess conditions, consider additional engineering controls, and discuss findings and potential responses with EPA.

• GE must stop work and inform EPA if additional sampling results exceed the air action level.

Last week, the EPA released a fact sheet indicating that airborne PCBs detected across the GE/Housatonic site were largely below the reporting level and do not pose a risk to human health.

That claim has been challenged by David Carpenter, a professor at the University at Albany, who says evidence suggests a correlation between health problems and exposure to airborne PCBs, measured in parts per billion (units 1,000 times smaller than parts per million).

PCBs, or polychlorinated biphenyls, were used as “dielectric fluids” in GE transformers until they were banned in the late 1970s because they were considered a possible cause of cancer. Dielectric fluids are used as insulators in high-voltage components, such as transformers, to prevent or quickly quench electrical discharges that could damage or destroy the equipment.

PCBs made by Monsanto and used by GE and other manufacturers were chosen for the job because they are stable, inert and resistant to fire and heat. General Electric used them at its power transformer plant from 1930 to 1977, and signed a 1972 agreement agreeing not to sue for health and environmental damage as long as it continued to sell the chemicals to GE.

But the qualities that made PCBs a good dielectric also made them harmful to the environment, as the chemical bioaccumulates when consumed by fish, birds, mammals and humans in the food chain. That’s why warnings have been posted along the Housatonic in Massachusetts and Connecticut advising fishermen and hunters not to consume what they catch.