A hazardous waste cleanup project is currently underway in Highland in the hopes of remediating a local contaminated wetland.
The contaminated stream is part of the Swartekill, a large wetland complex located near Rifton, New York. Transformer oils containing polychlorinated biphenyls (PCB) leaked into the storm sewer system, which then seeped through more underground pipes and into the wetland area. PCBs and polycyclic aromatic hydrocarbons (PAH), two types of contaminants, were discovered during a periodic property inspection from the Central Hudson (CH) Gas & Electric Elting’s Corners Facility in 2007.
“It’s suspected that the PAHs that have come into the wetland may have partially come from the Elting’s Corners site. It also could have run off from local roadways,” said John Maserjian, CH Director of Media Relations. “Those materials are no longer used and the site has been upgraded significantly over the years, so currently there is no issue with any contaminants coming from that site.”
PCBs and PAHs are common and pervasive contaminants that are often co-located and are the result of combustion, like car emissions. PCBs were widely-used in transformers to enhance the oil’s performance, but were outlawed in 1979, once potential health and environmental hazards were discovered. PAHs are often found in soil from side-of-road sites that vehicles frequently pass by, but were also most likely existent due to the active maintenance garage held on site.
Studies conducted on mixtures of PCBs and PAHs have concluded that these contaminants are most likely carcinogenic to humans. The bioaccumulation of PCBs (through the consumption of fish or other animal products) is presumed to produce the most carcinogenic mixtures, according to the Environmental Protection Agency.
CH and the NYS Department of Environmental Conservation (DEC) worked together to develop a recently-approved remediation plan at CH’s facility, located in Highland, New York. This facility’s cleanup activities are permitted through parts 373 and 375 of the the Environmental Conservation Law (ECL), which dictate waste management procedures.
“We have something called a wetland restoration plan that we are using,” said Kiera Thompson, senior engineering geologist in the Division of Environmental Remediation for the NYS DEC. “The goal is to leave the wetland better than we left it. That includes not just removing the hazardous material from the wetland, but also restoring it to a more native condition than what it was that’s better for wildlife.”
This project started in May and the remedial portion is expected to be completed in October. Samples will also be taken over the next five years to ensure that the area is completely clean. The intrusive portion of this project that began in June, which included the excavation of approximately 6,000 cubic yards of sediment, is complete.
The focus has since shifted to the refilling and restoration of the wetland, once the water is tested and treated on-site. The removed sediments are transported by protected trucks, lined with plastic sheeting and topped with a tarp, to Seneca Meadows, the largest active landfill in the state. It is specially-permitted to handle and store these non-hazardous waste materials. There, the soils are replaced with high-organic content, with a clean mix of soil and clay specific to wetland areas.
Restoration plans for this wetland will take place through the fall, which include: replanting native species and encouraging them to grow (i.e. cattails), implementing basking logs to help support the turtle population and other environmental enhancements.
“We are very confident that we’re doing everything we can to be protective of human health and the environment,” Thompson said. “In fact, that’s the goal of our remedial action. We have best practices in place.”