The Environmental Protection Agency on Friday designated a 1.3-square mile area in Connecticut waters between the mouth of the Thames River and the southeastern tip of Fishers Island as the site where sediment dredged from channels, harbors and ports can be disposed for the next 30 years.

The Eastern Long Island Sound Dredged Material Disposal Site, established over the objections of New York State, will be available to begin accepting sediment soon after the Dec. 23 closure of the two existing sites in the eastern Sound. One is at an adjacent location to the new site, and the other is in Cornfield Shoals off Old Saybrook.

Curt Spalding, regional administrator for the EPA, said the final contours and location of the site respond to New York State’s objections. It is smaller than the 2-square-mile site originally proposed, and will be able to accept about 20 million cubic yards of sediment instead of the 27 million the larger site would have been able to accommodate.

“We tried to be responsive to both sides of the issue,” Spalding said, adding that the agency reviewed 6,000 letters from the public, businesses and government officials over the eight-year process of public meetings, public informational sessions and comment periods. “We felt the need was there for an Eastern Long Island Sound disposal site, but we tried to make sure it was only as big as it needed to be.”

In addition to shrinking the size of the site, the EPA also moved the site to the west and entirely out of New York waters and about a mile from Fishers Island, Spalding said. The agency also established a Regional Dredging Team, comprising representatives of New York and Connecticut, the EPA and the Army Corps of Engineers, that will review each project and testing of material being dredged to ensure that as much sediment as possible is reused for beach replenishment and other land-based projects rather than dumped at the offshore site.

On Oct. 6, the New York State Department of State released a ruling rejecting the EPA’s proposed rule, arguing that it failed to explore practical alternatives to offshore dumping.

Spalding said it is unclear as yet whether New York will be satisfied with the changes made in the final rule and drop its objections. New York officials did not immediately respond to a request for comment.

U.S. Rep. Joe Courtney, D-2nd District, was among several Connecticut lawmakers who praised the EPA’s decision. He noted that the site also was moved out of a main navigation channel, in response to concerns raised by the Navy that the proposed site could have interfered with transit of submarines to and from the Naval Submarine Base in Groton.

“This is the final step in a long, exhaustive process that was very inclusive to all the stakeholders,” he said. “This is a huge development for the region.”

Establishment of a new site is good news for marina owners, Electric Boat and other companies that rely on dredging to keep their waterfront areas open, Courtney said. The Navy, which supported the establishment of the new site, is planning a pier construction project that will require 60,000 square feet of material be dredged from its waterfront.

“Having to carry that to the central or western Long Island Sound site would double the cost,” Courtney said, and could ultimately affect the long-term viability of the sub base.

The decision establishing the site does not authorize any specific dredging project. Individual projects must obtain site-specific permits from the Army Corps of Engineers, and dredge material must be tested for contaminants before it can be disposed at the site. Contaminated material must be taken to a hazardous waste disposal site.

Joining Courtney in praising the EPA’s decision were the state’s two Democratic senators, Richard Blumenthal and Chris Murphy.

“This decision appropriately balances vital economic and sensitive environmental needs — allowing dredging to proceed while also respecting the unique natural habitat of the Long Island Sound,” the two said in a joint statement. “The Sound helps inject $9 billion annually into our local economy, including 55,000 jobs throughout the region — work that depends on safe, reliable access to our waterways like the Groton sub base. We will actively monitor implementation of this plan to guard against any effort that undermines local environmental concerns.”

Gov. Dannel P. Malloy and Rob Klee, commissioner of the state Department of Energy and Environmental Protection, also applauded the EPA’s decision.

“The simple fact is that given the nature of our coastline, periodic dredging is required to ensure the navigability of waters and continued access to ports and harbors,” Malloy said in a news release. “While we continually seek opportunities for beneficial reuse of dredged materials, this approach is not always available. In those cases, we must maintain the option for well-managed open water disposal. The EPA’s decision ensures that the practical, environmentally sound, and cost effective option of open water disposal will remain available for dredging projects in Eastern Connecticut."

Klee said the EPA’s rule is consistent with Connecticut’s efforts to continue improving the environmental health of the Sound with upgrades to wastewater plants that discharge into the Sound, better management of stormwater runoff and development of a plan for the estuary.

He added that there are times when open-water disposal is the only reasonable option.

“Our experience over almost four decades shows that through careful oversight and management, open water placement of dredged materials has served our maritime needs without negative impacts on water quality, natural resources, aquatic life, or public health in Connecticut or neighboring states,” Klee said.

Spalding, the EPA regional administrator, said the site is in an area where “the currents are very mild,” meaning that sediments would not tend to migrate.

“It’s not a dispersive site at all,” he said. “The material will go down to the bottom and stay there.”

j.benson@theday.com