TURNERS FALLS — An equipment malfunction caused FirstLight Hydro Generating Co.’s Turners Falls dam to leak roughly 300 gallons of hydraulic fluid into the Connecticut River last week, marking the facility’s fourth such incident since 2021.

According to a statement from the hydroelectric company, FirstLight employees observed a sudden loss of hydraulic pressure in the dam’s bascule gate system on June 3 and, responding to the dam, saw an oil sheen below it.

FirstLight stated it then notified the Massachusetts Department of Environmental Protection (MassDEP), which responded to the spill, alongside FirstLight personnel and health, safety and environment professionals. The company noted that the dam system has since been stabilized and that there are currently “no indications of an ongoing leak of hydraulic fluid.”

“We note that initial indications suggest that this issue is likely due to the failure of a hydraulic system component and is not related to past issues with seepage from the bascule gate system that had been tied to aging pistons,” FirstLight Communications Manager Claire Belanger wrote. “Still, we continue to be on track to begin an overhaul of the bascule gate system this summer, a project we committed to in 2023 after previous remedial efforts failed to meet our expectations.”

As the spill remains under investigation, Belanger said crews have deployed absorbent booms in areas where a sheen is observed on the Connecticut River and will monitor the area until the issue is fully resolved.

In a joint statement issued on June 5, state Sen. Jo Comerford, D-Northampton, and state Rep. Natalie Blais, D-Deerfield, explained that the Turners Falls dam last leaked roughly 300 gallons of oil only three years ago, in 2022.

The legislators also noted that the leak occurred not long after FirstLight was issued its 401 Water Quality Certification from MassDEP in late April as part of its federal relicensing process.

“FirstLight’s team has said that it is actively investigating the issue and that it is on track this summer to undertake an overhaul of the bascule gate system to address the issues that caused the previous oil leaks,” Blais and Comerford wrote. “We call on FirstLight to prioritize this work, already much too delayed. We also urge MassDEP to hold FirstLight accountable by reviewing prior infractions and taking the steps necessary to ensure compliance with environmental requirements and to deter future violations.”

Representing FirstLight, Belanger wrote that the company takes full responsibility for resolving the issue and will keep the public informed during the cleanup process.

“FirstLight reiterates that any release of oil to the river is unacceptable, and we take full responsibility for the swift and thorough resolution of this issue,” Belanger wrote. “We will provide updates as we have them and thank the Massachusetts Department of Environmental Protection for their advice and support as we investigate and seek to fully resolve this issue.”

Anthony Cammalleri can be reached at acammalleri@recorder.com or 413-930-4429.