Clean sediment could ease path for swift removal of Pittsfield mill dam
PITTSFIELD — Within the next few years, the West Branch of the Housatonic River around the Tel-Electric Dam could be free-flowing and restored to its natural state — and part of a riverway recreation area stretching from Wahconah Park to Clapp Park.
That was the assessment of a representative of the state Division of Ecological Restoration of the Department of Fish and Game, who gave a presentation on Thursday at Conte Community School.
Alex Hackman, manager of a multi-stakeholder project to remove what is also known as the Mill Street Dam, described the project's history and how the work is likely to progress, beginning in 2017.
The project calls for removing the 18-foot high, 40-foot wide concrete dam, an abandoned hydropower facility that originally provided power to nearby mills, as well as an abandoned steel railroad bridge 75 feet upstream from the dam.
The work also will deal with up to roughly 9,000 cubic yards of sediment that has built up behind the dam, and Hackman said testing for pollutants in the material has thus far found encouraging results.
He said the project is now at the 30 percent design stage and an environmental impact assessment comment period is underway. The Division of Ecological Restoration, which works on similar waterway restoration projections around the state, is seeking approval for an expedited environmental review process because the work is expected to restore river water quality and fish and wildlife habitat and remove a potential threat to public safety should the 96-year-old dam fail just west of the city's central downtown area.
The project manager also addressed studies of the sediment built up behind the dam, which detected "very low" levels of PCB, petroleum-based or heavy metal contamination, such as mercury, which would be expected to slow and complicate the dam removal and increase the cost.
The river in the section meanders past Wahconah Park on Wahconah Street before meeting up downstream with the East Branch of the river and heading toward the Lenox line. The western branch, unlike the eastern, is not directly downstream from the former GE operations in central Pittsfield.
Funding lined up for the project includes $750,000 awarded the city in 2008 as part of the GE consent decree settlement related to PCB pollution from Pittsfield industrial sites, and $1 million in federal grant funding recently allocated to the state.
Efforts to remove the dam intensified after 2000, when an inspection found the structure "in overall poor condition with significant operational or maintenance deficiencies." The project planning has since involved several state agencies, the city and the U.S. Fish and Wildlife Service.
Hackman said an initial round of testing on the sediment behind the dam showed levels of PCBs, petroleum-based substances and heavy metals that were well below levels considered a threat to human health.
"It is a pretty good finding so far," he said Thursday.
The significance, Hackman said, is that this might allow the contractors to simply remove debris, such as a number of shopping carts, tires or other items in the sediment and remove a minimum amount of earthen material to a regular landfill site for disposal — as opposed to a hazardous waste landfill, which would dramatically increase the cost.
If dredging and disposal of hazardous sediment were required, he said, the cost could rise by several million dollars, while a project requiring no disposal at a hazardous site would only involve breaching the dam in stages and allowing the silt to move downstream with the river flow.
Hackman said that process, which has been used at other dam sites, has resulted in a naturally flowing river section with clearer water and better fish habitat, healthier water temperatures and oxygen levels within a few months. After more time and some heavy rains, the sediment will deposit itself downstream as it would have without the dam in place, he said.
In addition, Hackman noted that the city is planning the Westside Riverway through the section of riverbank in an urban revitalization effort. Currently, he said, secluded areas around the dam have been the scene of illegal drug use — evidenced by hypodermic needles often found in the area — and other activities or crimes.
The dam structure, owned by Nash family, which also owns a nearby building, is behind the rear parking area for the Clock Tower Business Park on South Church Street, which houses The Berkshire Eagle and other businesses.
Jane Winn, of the Berkshire Environmental Action Team, who attended the presentation, said later, "This looks like a great ecological restoration project that will benefit a Minority and Income Environmental Justice Neighborhood, as well as the critters in the west branch of the Housatonic River. It will definitely improve safety at the Mill Street dam site."
Winn added, "We are looking forward to someday being able to canoe from Wahconah Park to Clapp Park (in higher water)."
Contact Jim Therrien at 413-496-6247.
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