Nassau County officials have issued a boil-water order for residents in Long Beach after discovering E.coli in the local water supply.

“The City of Long Beach Water System, in consultation with the Nassau County Department of Health, is investigating the source of the contamination,” officials said in a press release Friday. “The boil water alert will remain in effect until all water sampling results indicate that the water is free of bacteria and safe to consume.”

The existence of the E.coli was confirmed earlier in the day by the Health Department, which had been sent a “distribution sample result” collected from the Long Beach Water System.

“Based on the sampling result, Nassau County Department of Health has ordered the City of Long Beach Water System to issue a Boil Water Alert to their community,” said Nassau County officials. “Consumers of the City of Long Beach Water System are strongly advised not to drink the water without boiling it first.”

Residents have been advised to “bring all water to a boil, let it boil for one minute, and let it cool” before using. Officials said the presence of the E.coli “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,” Friday’s press release said. “They may pose a special risk for infants, young children, elderly, and people with severely compromised immune systems.”