TURNERS FALLS — Despite an anticipated multi-day dam repair that prompted an emergency drawdown of the Connecticut River, FirstLight Hydro Generating Co. confirmed Wednesday that the repairs were completed ahead of schedule.

According to FirstLight Communications Manager Claire Belanger, the energy company was able to repair a failed hydraulic supply line at Bascule Gate 2 on Tuesday and the river refill started that evening.

“After drawing down the impoundment in the early hours of July 8 and reaching river levels necessary for the FirstLight team to safely access the gate, personnel entered the gate, investigated the issue, implemented repairs, and completed testing to ensure the hydraulic system and gate were functioning properly,” Belanger said in a statement.

The repair was done following a spill of 445 gallons of hydraulic oil into the Connecticut River on June 3. The oil spill only impacted Bascule Gate 2, with gates 1, 3 and 4 operating as intended. According to FirstLight, employees observed a sudden loss of hydraulic pressure in the dam’s bascule gate system and, responding to the dam, observed an oil sheen below it.

FirstLight previously stated it notified the Massachusetts Department of Environmental Protection, which responded to the spill, alongside FirstLight personnel and health, safety and environment professionals. The Massachusetts Executive Office of Energy and Environmental Affairs has a Waste Site & Reportable Releases Information webpage detailing the spill. In response to this spill, MassDEP issued FirstLight a Notice of Responsibility, dated June 16.

Last week, FirstLight stated its anticipated repair timeline could be between one and five days. With the drawdown only taking one day, Belanger described the repair timeline as the “best-case scenario.” She noted a piston will need to be replaced in the future, but that does not require a drawdown.

Additionally, FirstLight successfully relocated mussels in the Connecticut River in areas of New Hampshire and Vermont north of the Turners Falls dam, putting them into watered portions of the river. According to Belanger, there were plans to move mussels in Massachusetts on Wednesday, but with the repairs done early and the river refilling, the effort was called off.

Although the drawdown was expected to lower river levels 6 feet below the dam’s minimum operating level of 176 feet, residents along the river reported lowered river levels prior to the drawdown starting. The impoundment’s normal level is 180 feet.

Belanger previously explained that with Bascule Gate 2 in a slightly upright position, water was leaking from the gate prior to its repair. That problem, combined with low natural flows, led to the lowered river level.

The June oil spill is not the first at the Turners Falls dam. There have been five oil spills of varying scale since 2020, with a 2022 spill releasing 300 gallons of hydraulic fluid into the river from pistons within Bascule Gate 4.

“Previous issues were related to piston pitting,” Belanger explained Thursday. “We’ll begin the three-year piston replacement project this year to fully overhaul the pistons and address the cause of previous oil leaks. During that project, we will be replacing system components, such as hydraulic supply lines, that haven’t already been recently replaced.”

This week’s effort will not be the only drawdown this year, though. The Turners Falls Power Canal will have its annual maintenance drawdown from Sept. 21 to Sept. 27, per an announcement during Monday’s Montague Selectboard meeting.

The most recent oil spill and the emergency drawdown come as FirstLight continues to move forward in the process to obtain a 50-year license from the Federal Energy Regulatory Commission (FERC) for its Connecticut River hydroelectric facilities. FirstLight has been operating the Turners Falls dams and the Northfield hydro-pump facility under a temporary license since 2018. This relicensing effort has faced opposition from the Connecticut River Conservancy and other regional groups like the Franklin Regional Council of Governments (FRCOG) and American Rivers.

Two in-person public hearings on the FERC relicensing will be held at Greenfield Community College on Wednesday, July 16, with one from 9 to 11 a.m. and another from 6 to 8 p.m.

Erin-Leigh Hoffman can be reached at ehoffman@recorder.com or 413-930-4231.