In a decision that Connecticut Attorney General William Tong called “a major victory for Connecticut’s maritime economy,” the U.S. District Court in New York has upheld the state’s choice of a new dredge disposal site in eastern Connecticut.

The 1.3-mile underwater site, between the mouth of the Thames River and Fishers Island, was designated by the Environmental Protection Agency in 2016 and viewed as crucial to maritime businesses like Electric Boat and Cross Sound Ferry, along with the Naval Submarine Base. A host of industries depend on periodic dredging of area channels, marinas, boatyards and harbors.

But the use of the site was blocked in 2017, when New York’s Department of Environmental Conservation and secretary of the state sued the EPA, claiming the dredge site would harm the Sound’s ecosystem and interfere with navigation.

In a 42-page decision issued on Friday, U.S. District Judge Edward R. Korman cleared the path for use of the site and granted summary judgment to the EPA and to the Connecticut Department of Energy and Environmental Protection, which had intervenor status.

“So long as there are practical limits to the beneficial uses of dredged material, there will be fierce disputes over where such material goes,” Korman wrote in his decision.

He concluded that the EPA, in choosing the site, had based its findings on “substantial evidence, and followed the agency’s obligations under the law.”

“Thousands of jobs and billions of dollars in revenue depend on the ability to dredge and safely deposit materials,” Tong said in a statement. “The Eastern Long Island Sound site was selected after exhaustive review and public input, and any disposal of dredged materials will require full environmental review and compliance with Connecticut water quality standards. The New York challenge was without merit.”

U.S. Rep. Joe Courtney, D-2nd District, agreed, saying the decision validated years of work by the EPA to ensure that materials deposited would be analyzed and screened to avoid environmental impacts. That work had included accommodations for New York that involved shrinking the site and moving it completely into Connecticut waters.

Before the site may be used, EPA and the Army Corps of Engineers also must develop site management and monitoring plans.

“The groundswell of input from small marinas, local and state officials, and large stakeholders such as the Naval Submarine Base New London, Cross Sound Ferry, and Electric Boat, clearly made a decisive impact on Judge Korman, who frequently cited their amicus briefs and affidavits,” Courtney said in a statement.

Courtney said on Tuesday that the decision will create a “stable horizon” for the submarine base and help to keep it off future base closure lists. Dredging is an absolute requirement for the ongoing submarine building activities at EB, he said.

There are two other EPA-designated dredge sites in Connecticut waters, known as the central and western disposal sites, which primarily serve New Haven and points west, including New York.

William Gash, executive director of the nonprofit trade association Connecticut Maritime Coalition, said those sites are cost-prohibitive and less environmentally friendly, considering the long distances barges and tugs must travel to reach them.

He welcomed the news of the court decision and said “having that disposal site in eastern Connecticut is really a multiplier for businesses.”

David Kooris, chairman of the Connecticut Port Authority, said the dredge site doesn’t directly impact the $157 million State Pier reconstruction project in New London but called it a major win for the maritime economy, especially water-dependent businesses in southeastern Connecticut.

“This will lower costs for dredging for harbors and marinas across eastern Long Island Sound, making investment easier in the infrastructure necessary to underpin our working waterfronts,” Kooris said.

g.smith@theday.com