LONG ISLAND (WCBS 880) — Health officials in Nassau County are warning residents to boil water before using after the dangerous bacteria E-coli was found in the water supply.

LISTEN: WCBS 880’s Long Island bureau chief Mike Xirinachs reports

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The advisory includes North Valley Stream, Elmont, Franklin Square, Garden City, Stewart Manor, Floral Park and New Hyde Park.

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The Water Authority is flushing out and disinfecting the system. They’ll have to do more testing before lifting the advisory.

Michael Tierney, superintendent at the Water Authority of Western Nassau County, told 1010 WINS the earliest the advisory could be lifted is late Friday or early Saturday.

In addition to boiling water, official say residents can also use bottled water and should toss out ice cubes.

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For more information, visit www.wawnc.org.