[B]URLINGTON — The level of contamination in dirt piles being stored at Leddy Park do not rise to the level of hazardous waste, according to the federal Environmental Protection Agency, meaning the city will have to dispose of it.
The cheapest and best option for dealing with the soil is to reuse it as alternative daily cover at Vermont’s only landfill in Coventry, said Jesse Bridges, director of the Department of Parks and Recreation. That will allow the city to bypass a $26 per ton fee for disposing of the dirt as solid waste, Bridges told residents at a public meeting Thursday.
According to the Solid Waste Association of North America (SWANA), a daily cover of six inches of compacted soil has been standard for more than 30 years in sanitary landfill design and operation. Covering the landfill prevents adult flies from emerging out of the solid waste mass, according to SWANA.
Bridges said that the Coventry landfill, which is operated by the waste management company Casella, has agreed to use the contaminated soil as cover.
“We are not happy that the landfill is the only option, so we are still continuing those discussions,” Bridges said.
One of the other options that was considered to manage the soils was using it as a component of asphalt, said Chuck Schwer, director of the Waste Management and Prevention Division in the Vermont Department of Environmental Conservation. That would involve taking the soil all the way to New Hampshire to be processed and then bringing it back, he said, the cost of which would be difficult for the city to handle.
Asked why the soil was moved to the Leddy Park parking lot to begin with, Bridges said it offered large enough space that would keep the soil in the parks division, rather than placing it on land managed by another entity.
The soil was excavated last year by the Parks and Recreation Department as part of the Waterfront Park construction project three miles away. Waterfront Park rests atop an old industrial railyard, and while the city was aware the soil had some contamination, it was not aware that it contained polychlorinated biphenyls (PCBs). PCBs are classified as carcinogenic by the International Agency for Research on Cancer.
Schwer said it’s possible officials would have done something different with the soils had they known about the presence of PCBs. Were it not for the PCBs, Burlington would have more options for reusing the soil, officials said.
Before additional testing of the piles that was completed in September, there was some debate on the jurisdiction of the soil piles. PCB’s normally fall under jurisdiction of the EPA, but the agency decided the piles were not contaminated enough to be classified as hazardous waste, said Trish Coppolino, coordinator of the DEC Brownfield Program. That makes them Burlington’s responsibility.
The contaminated soil is being inspected weekly by the Johnson Co., the consulting firm that conducted additional testing required by the state and federal Environmental Protection Agency in September, Bridges said.
Kurt Muller, a senior engineer at the Johnson Co., said that the piles of soil at Leddy Park contain both polycyclic aromatic hydrocarbons (PAH’s) and polychlorinated biphenyls (PCB’s).
Muller said that these contaminants are relatively common. PAH’s are essentially exhaust and whenever someone eats burned chicken they are exposed to them, he said. PCB’s are a little less common, he said, though they can be found in grout between floor tiles and electrical equipment among other things. Muller said that the levels of PCB’s found in the samples were about 10 times lower than the levels found in hazardous waste.
“This isn’t an anomaly site,” Muller said. “These are standard industrial soils and I see this type of contamination at these levels of concentration consistently.”
At a September public meeting, Bridges and other city officials presented a timeline for the removal of the soil piles, which gave the city until Dec. 15 to decide what to do with the soil, allowing them to carry out their plan in the winter of 2016.
Bridges said that the city is a few weeks ahead of that timetable.
Muller said removing the soil should take about 10 days. The soil will be loaded onto trucks and there will be a traffic flow plan to monitor that. At the end of each day, the covering and fencing currently surrounded the piles will be put back in place, Muller said. When the excavation process is over, part of the inspection will be cleaning up any residual soil, he said.
“At the end of the entire project, the idea is that the surface returns to what it looked like prior to the piles being there,” Muller said.