KINGS PARK, N.Y. — Environmentalists and elected officials in New York are rekindling a long-running dispute with Connecticut over dumping what critics say is potentially harmful silt from dredging projects into Long Island Sound, the massive waterway that separates the states.

The fight centers on the Environmental Protection Agency’s proposal that would permit additional disposal of dredge materials at several sites in the sound for the next 30 years. Democratic Gov. Andrew Cuomo said Thursday the state would consider legal action if federal officials proceed.

“The Long Island Sound is one of New York’s greatest natural treasures and a vital component of Long Island’s tourism industry,” Cuomo said. “The EPA’s plan to establish a new disposal site not only poses a major threat to this ecologically vital habitat, but impedes our progress in ending open water dumping in Long Island’s waters once and for all.”

Cuomo was joined by a bipartisan contingent of elected officials and environmentalists at a news conference at a state park overlooking the water, with the shoreline of Connecticut in the distance.

“The public loves this water body and has always considered Long Island Sound to be an extension of our home,” said Adrienne Esposito, executive director of the Citizens Campaign for the Environment. “We consider the Sound as our front yard, or our backyard but never as a junkyard. We expect the EPA to protect the Sound, not pollute the Sound.”

An EPA spokesman said a final decision on dumping, which has been permitted since the 1980s, would be made later this year.

“Dredging is needed to ensure safe navigation in the sound,” said EPA spokesman Dave Deegan.