Hartford — Backed by Connecticut lawmakers and hundreds of maritime businesses that bank on periodic dredging of area channels and harbors, state Attorney General William Tong recently filed a brief in U.S. District Court responding to New York's effort to block a 30-year silt disposal site in Connecticut waters between the mouth of the Thames River and southwestern tip of Fishers Island.

New York's Department of Environmental Conservation and Secretary of State sued the Environmental Protection Agency in 2017, arguing the agency's selection of the Eastern Long Island Sound Disposal Site would harm the Sound's ecosystem, introduce contaminants into the food chain and interfere with navigation in the Sound between New York and New England. The lawsuit has sparked ongoing responses from Connecticut businesses and lawmakers who argue that dredging is crucial to the maritime economy and that the EPA selected the site after a years-long process that included input from the public, businesses and government officials in several states.

"The record is abundantly clear — the selection of the Eastern Long Island Sound Disposal Site was done properly and lawfully and must proceed. Thousands of maritime jobs and billions of dollars in revenue depend on the ability to dredge and safely deposit materials," Tong said in a statement Wednesday.

U.S. Rep. Joe Courtney, D-2nd District, worked with Tong to document the depth of economic impact and support from the maritime business community, which has previously filed briefs in the case.

In an interview Thursday, Courtney noted New York "had a seat at the table" during "a very protracted process" before "surprising everyone" with the attempt to block the site. Courtney said the site, once open, would "allow a very safe and functional disposal program exclusively in Connecticut waters in the interest of being a good neighbor to New York."

"This is a very progressive dredging plan that tries to be sensitive to the public hearings held on both sides of Long Island Sound," Courtney said. He added that the site selection dated back to the 2005 Dredge Material Management Plan for Long Island Sound, which governors in Connecticut, New York and Rhode Island agreed to. Blocking the site, Courtney said, would "disproportionately harm Connecticut's eastern shoreline and economic activity, including recreational boating, commercial maritime transportation and shipbuilding, and important projects at the Coast Guard Academy and SUBASE New London."

The Army Corps of Engineers has found that without dredging, the ability to launch and build submarines in Groton "would be eliminated," noted Tong, who filed his brief on behalf of the state Department of Energy and Environmental Protection.

The ability to maintain marina depths and "navigational access is their lifeblood," said Connecticut Marine Trades Association Executive Director Kathleen Burns of her group's 350 members across the state. "It's 7,000 employees, really a string of small businesses, so every dollar counts."

Burns said "considerable research" went into the Dredge Material Management Plan, taking into account economic, scientific and environmental factors.

Tong's filing argues that New York's complaints — among them that EPA arbitrarily inflated projected volumes of dredged materials to justify the site while underestimating contaminants and navigational impacts — are without merit. Tong further argues that New York officials "have had ample opportunity for notice and comment" on the process before they filed a lawsuit, and they "have not, and cannot, point to any relevant evidence contradicting the EPA's record."

The EPA in 2016 shrank the size of the eventual site from 2 square miles to 1.3 — holding about 20 million cubic yards of sediment instead of 27 million — and shifted it entirely into Connecticut waters in response to New York's initial objections. Proponents of the site note that sediment must be tested before disposal permits are issued, and contaminated material cannot be deposited in open-water sites.

The EPA also established a Regional Dredging Team, comprising New York and Connecticut officials, the EPA and the Army Corps of Engineers, that will review each project and ensure as much sediment as possible is reused for beach replenishment and other land-based projects rather than dumped at the offshore site.

The Army Corps of Engineers and EPA have said the volume of material necessary to keep federal waterways open is too great to be fully accommodated by upland disposal sites, with Courtney saying tidal wetlands and beach replenishment is ideal, "but at some point, it's about math."

Courtney and Burns said it was impractical, cost-prohibitive and not environmentally friendly to transport dredged materials from area waterways to two other sites designated by the EPA: the Central Long Island Sound Disposal Site south of South End Point in East Haven, which typically accepts dredged material from New Haven, Bridgeport, Stamford and Norwalk Harbors and other adjacent coastal areas, or the Western Long Island Sound Disposal Site south of Long Neck Point in Darien, which takes materials from Stamford, Norwalk and other Connecticut and New York coastal communities.

"Lugging that stuff longer distances would add tremendous costs to dredging projects and result in more carbon emissions," said Courtney, who added that local facilities such as the Naval Submarine Base and Electric Boat have modernized and "built-in systems to make sure hazardous waste isn't just dumped into the ocean."

New York's Department of State in 2016 said it was "fully supportive of dredging for maintaining" water-dependent uses and navigation infrastructure, and it could support designating a long-term disposal site in Niantic Bay instead of the Sound.

Katie Dykes, commissioner of the DEEP, said in a statement that Connecticut was "committed to environmentally responsible management of dredged material."

"The availability of the Eastern Long Island Sound Disposal site for use by eastern Connecticut maritime interests is essential to support the vitality of our marine economy in an environmentally responsible way," she added.

Messages left with DEEP, EPA, the Army Corps of Engineers and New York officials were not immediately responded to Thursday afternoon.

Courtney said oral arguments in the case, which is being handled by the U.S. District Court for the Eastern District of New York, could be heard later this summer.

b.kail@theday.com