HEMPSTEAD, N.Y. (CBSNewYork) — Officials in Nassau County announced the beaches temporarily closed following the discovery of used hypodermic needles and other medical waste were once again open for business.

A Town of Hempstead lifeguard spotted the first needle on Friday afternoon, placed it in a Gatorade bottle, and called 9-1-1. The discovery prompted the closure of East Atlantic Beach throughout Saturday.

Town officials initially said they’d close the beach for at least two high tides, making sure no additional waste washed ashore. More hypodermic needles were found Saturday afternoon, extending the closures to all Hempstead south shore beaches along with Nickerson and Malibu Beaches through early Sunday.

“The concern is always that a resident finds it by stepping on it, or gets injured by a needle or somehow comes into contact with potentially contaminated material,” Hempstead Town Supervisor Laura Gillen said.”

Crews with hand rakes and heavy sand shifters criss crossed the beach early Sunday, trying to pick up needles which officials say can be easily buried in the sand.

“At the shore line it was just a big line of plastic,” East Atlantic Beach Michael Luciano said. “Every color you could imagine. It’s really a problem, it was a disgrace.”

Clean up crews also had a boat in the water scanning for floating debris. All the while, a team of investigating agencies continue to probe the big question — where did all the trash come from?

“We’re all having nightmares of things we heard a decade ago or more when medical waste washed up on the shore,” State Senator Todd Kaminsky (D-9th) said. “This is very serious.”

Investigators said some of the washed up supplies had serial numbers printed on them, which may give a clue to their origin.

By 10 a.m. Sunday, officials determined East Atlantic, Nickerson, and Malibu Beaches were safe enough for public use.