Ledyard ― About 200 people jammed into the auditorium at Ledyard Middle School on Thursday night to protest plans for a rock quarry operation at the former Dow Chemical property.

They were there to oppose a planned quarry they said would threaten their health and well-being as well as largely level the historic Mount Decatur in the Gales Ferry section of town.

However, they never got the opportunity to address the Planning and Zoning Commission as the developers of the quarry took the floor until 9 p.m., when the meeting’s Zoom session was interrupted and could not be reconnected. The hearing is now expected to be continued on Thursday, Dec. 21, at 6 p.m. at the middle school.

A final decision on the application is not expected until Jan. 11 at the earliest, as the public hearing is planned to continue until that date.

Harry Heller, an Uncasville attorney representing the site operator Gales Ferry Intermodal, argued at the beginning of the meeting that the project fits within the historic use of the 150-acre property as a transportation hub and industrial site.

He promised that the owner, Cashman Dredging & Marine Contracting, a company based in Quincy, Mass, would be a good community partner.

“They are here to stay, and they intend to be a good corporate citizen within the Town of Ledyard and the regional community,” he said.

While residents never got the chance to speak, there was chatter among the audience about their opposition to the quarry operation that would leave 26 acres of developable land at its conclusion.

One woman, who identified herself as Terri Isenburg, periodically waved a sign that read “Crystalline Silica Group 1 carcinogen can lead to: Lung Disease, Silicosis, Lung Cancer Caused by Quarry.”

The quarry at historic Mount Decatur is being fought by a group called Citizens Alliance for Land Use, which has cited the potential for noise, vibrations and air pollution, especially so-called fugitive dust, small particles emitted during the quarrying process that are known to cause respiratory problems.

During his presentation, Heller promised to limit the number of truck trips back and forth to the site to 100 a day. He added that other steps will be followed to mitigate the operation’s effect on local citizens, particularly the issue of dust created in the excavation and processing of rocks on site.

The dust problem, he said, would be handled by using machines that shoot water into the air to ensure particles don’t become airborne. Devices integrated into drilling and processing equipment will address the dust issue, he said, and water will also be shot into the air during blasting.

“A water truck will be maintained on site at all times,” Heller added.

He added that Gales Ferry Intermodal would be leaving 3.3 acres undisturbed through the first four phases to act as a buffer and a screen to reduce the excavation’s impact on residents. This area will be leveled only in the fifth and final phase of the project, which is backed by the Chamber of Commerce of Eastern Connecticut.

“This site is not pristine,” Heller added, pointing to a slide showing the effects of a 200-foot Eversource Energy powerline easement on the site.

He also pointed to an extraction operation at Baldwin Hill in Ledyard that has been ongoing for many years and recently received a permit from the Planning and Zoning Commission.

As for the destruction of Mount Decatur, where a fort and outpost once were located during a key phase of the War of 1812, Heller said those areas would be preserved even as the areas around them would be excavated. Cashman Marine has hired a historic preservation consultant to identify the areas where there are historical areas of significance or artifacts, a survey that is ongoing, he said.

But residents have been vocal about the incursion on a historic district as well as expressing concerns about the effects of blasting on the neighborhood, a nearby day care center and the Thames River Estuary.

l.howard@theday.com