Lee — As required by the 2020 Final Revised Housatonic Rest of River settlement agreement, General Electric Company (GE) must monitor non-GE-owned dams on the Housatonic River in Massachusetts, including the Columbia Mill and Willow Mill dams. On November 4, the results of this year’s annual inspections of those dams made by GE subcontractor GZA GeoEnvironmental Inc. (GZA) were released. The reports were based on a September 3 inspection of both dams by GZA staff and representatives of the Environmental Protection Agency (EPA). Per the reports, the dams were in about the same overall conditions as reflected in the team’s 2023 review a year ago.
The 2020 agreement was part of a proposal to remediate the Housatonic Rest of River—from the confluence of the waterway’s east and west branches through Connecticut—following years of GE depositing now-banned toxic polychlorinated biphenyls (PCBs) into the waterway from its Pittsfield plant.
Why is the welfare of these dams important?
Lee residents have long feared that a dam break or overtopping would release PCBs into the river flow downstream, endangering surrounding tracts and residents. A June 2023 protest highlighted the possible catastrophic results from such a malfunction at Woods Pond. According to organizer Clare Lahey, the Columbia Mill Dam constitutes a line of defense that, together with the dams at Woods and Rising ponds, holds back a major emergent flood of PCBs. Should these local dams break or overflow, a water torrent would be released, carrying PCBs into the floodplain and impacting Berkshire towns, she said.
Other local environmental groups have claimed that climate change might increase the chances of that scenario happening.
Columbia Mill Dam
Owned and operated by Lenox Development LLC, the Town of Lee has cited particular concern about the condition of the Columbia Mill Dam. “The town has submitted comments [to the EPA] on dams, in particular the Columbia [Mill] Dam which was in the worst condition,” he stated to The Berkshire Edge in an email response. “Since that time repairs have been made to Columbia Dam so it can function until it is dredged and removed.”
Although the Columbia Mill Dam is slated to be taken down during the remediation process, repairs were required to avoid dam failure before the structure is dredged and removed. According to the report, those repairs were made in July to correct issues observed during the August 2022 annual inspection, including the cause of the vortex condition, or dam vibrations. “During the September 2024 annual inspection, the repairs appeared to be in good condition…,” the report stated.
A February 2023 correspondence from the town to the EPA provides a list of repairs that should be made given the “lack of a physical early warning system at the dam.”
A copy of that communication can be found here.
The Berkshire Edge is awaiting a response from the EPA as to whether all repairs were performed.
The report also noted “moderate cracking” and “exposed reinforcement” on the mill building’s outside wall, the left side of the dam, as well as “a slight bulge” in a stone masonry wall, with those observations being “similar” to previous inspections. The document assumed, based on officials’ observations, that a gate controlling the flow of water into the flume upstream leaks.
Although most aspects of the inspection showed the dam to be in “adequate condition,” the downstream area was found to be “in good condition.”
Whereas GZA recommended visually monitoring the repairs and other conditions as well as removing previously cut vegetation downstream, the report provided that no further repairs were recommended.
A copy of the Columbia Mill Dam report can be found here.
Willow Mill Dam
For the Willow Mill Dam report, GZA cited “minor cracking” and “some deterioration” on certain parts of the structure, with minor leakage that was “greater than that observed during the 2023 Annual inspection” but with a similar depiction that was shown in photographs from a 2022 report. The dam is owned and operated by Onyx Specialty Papers Inc.
Although the report provided that each facet of the structure “appeared to be in generally adequate condition,” it noted some loss of mortar and missing masonry blocks and bricks including in the retaining wall below the bridge downstream of the dam. Some broken railing sections were also spotted.
GZA recommended continuing to monitor the dam sections, especially during low-flow conditions, and added maintenance actions including repointing masonry joints, removing debris from the dam’s drainpipe, keeping the 20 feet around the dam free from trees and other vegetation, and repairing the broken and missing handrails.
A copy of the Willow Mill Dam report can be found here.
According to Brittain, SKEO—the EPA contractor that provides analysis of reports incurred in the Housatonic Rest of Remediation project—does not review any of the dam inspections involved in the plan.
