Lindell, East, and West elementary schools were closed Monday out of an abundance of caution after a student came down with a suspected case of E. coli, but all schools are expected to reopen Tuesday.
Officials in Nassau County had issued the Boil Water Alert for all businesses and residents after a water sample tested positive late last week.
Other schools in the area remained open because their water comes from a different source.
"The health and safety of our residents is always the highest priority of Nassau County," Nassau County Executive Laura Curran said. "We will continue to work alongside our municipalities and water districts to ensure that every drop of our water supply remains clean and reliable."
The county's department of health had extended the alert through Monday, but after two negative tests, the boil water advisory was lifted.
The city had increased its chlorine levels and had been flushing from distal locations in the distribution system to draw the higher chlorine levels throughout the system.
Watch the press conference below:
"After two rounds of favorable results, the boil water advisory for this community will be lifted effective immediately," Health Commissioner Dr. Howard Zucker said.
The water has also bee deemed safe to drink, but Dr. Zucker cautioned that officials may never know where the source of the E. coli.
"We must also thank our city's workforce that once again stepped up in the face of a crisis," Long Beach City Councilman Anthony Eramo said. "Their hard work to protect our community from a threat to our safety and welfare did not go unnoticed."
Over the weekend, Governor Andrew Cuomo deployed 115,000 bottles of water to Long Beach residents to ensure access to clean water for residents and visitors.
"The health and safety of New Yorkers is paramount, and during difficult situations, we will always do everything in our power to ensure communities get the resources they need," Cuomo said. "This situation on Long Beach was no different. I am pleased to report state and local health officials were able to take immediate action to resolve the situation and the Boil Water Order has been lifted. I have also directed the State Department of Health Commissioner, Dr. Howard Zucker, and his team to investigate the source of contamination and to identify ways to ensure this doesn't happen again."
Residents in the neighboring town of Hempstead were assured their water supply was not affected, and Lido Beach/Point Lookout Water District water was safe for all uses. Island Park and Atlantic Beach residents, who are served by American Water, were also assured their water was safe.
E. coli is a bacteria whose presence indicates that the water may be contaminated with human or animal wastes. Microbes in these waters can cause diarrhea, cramps, nausea, headaches, or other systems.
* More Long Island news
* Send us a news tip
* Download the abc7NY app for breaking news alerts
* Follow us on YouTube