The state police bomb squad was called to Chappaquiddick Friday after the discovery of two World War II practice bombs, later determined to be inert, on a remote section of barrier beach at Cape Pogue.

The discovery comes along with news that the Army Corps of Engineers plans to begin a lengthy cleanup of World War II-era ordnance on Chappaquiddick next spring.

Chris Kennedy, Vineyard superintendent for The Trustees of Reservations, said the two bombs were found by a contractor working for the Army Corps of Engineers. The three-pound practice bombs, called AN-MK-23s, were found on the outside beach at Little Neck.

Little Neck is part of the Cape Pogue Wildlife Refuge, which is owned by the Trustees. The 62-acre area has been closed to the public for years because of World War II-era bombs.

Several Vineyard beaches were used as part of bomb target practice during World War II, including South Beach and Norton Point in Edgartown, part of a barrier beach on Tisbury Great Pond, and Cape Pogue. Bombs lodged in embankments are often unearthed by erosion.

Between late 2008 and the end of 2014, at least 602 munitions were found at Cape Pogue, of which 88 contained explosives.

Local police and the Massachusetts State Police bomb squad were contacted Friday after discovery of the practice bombs. The bomb squad, on the Island already as part of President Obama’s security detail, was able to respond to the small island off Edgartown about 20 minutes later, Mr. Kennedy said. On their Facebook page, The Trustees thanked Edgartown Sgt. Joel DeRoche and state police Sgt. Jerry Galizio “for their quick action.”

“Generally when you look at these things there’s no way for a lay person to figure out, are these things alive or are they expended,” Mr. Kennedy said. But the bomb squad quickly determined that these two bombs had already been expended and were inert.

“The problem is about 20 per cent of these things have been found to be still live,” Mr. Kennedy said. The live bombs can be dangerous; they still have a gunpowder charge that shoots out a red phosphorous pyrotechnic material.

The Army Corps has outlined a plan to remove the munitions at Little Neck. Another plan to remove munitions from other Vineyard areas has been recommended at a price of $9.8 million.

Mr. Kennedy said that work on Cape Pogue is expected to begin in late March, when Army Corps engineers will begin clearing vegetation from about 60 acres of upland area. That work will cease during shorebird nesting season, from June to August. Meanwhile, he said the underwater ordnance teams will go to work, with divers clearing more than 140 acres in Cape Pogue bay of munitions. In the fall, the bomb removal team will come back to work on the upland area, and will work throughout the winter.

“The big question is how long it’s going to take them to do all the clearing,” Mr. Kennedy said, adding that some estimates say it could take as long as a year. After the work is done the Army Corps will come back with all their equipment to make an assessment, and look for bombs that might have been missed.

Last December, removal of the munitions from land was expected to cost about $3 million, and the water removal was estimated at nearly $5 million.

Once everything is cleared, the Little Neck area could be safely opened for public access for the first time essentially since the end of World War II, Mr. Kennedy said. “It would be wonderful to get it open again,” he said.

He said the Trustees will continue to provide updates. “This will be a long-term project,” he said.