Although tests in the Greenlawn Water District indicate the water is safe to drink and use, the district's boil-water alert will remain probably until Sunday as a precautionary measure, superintendent Robert Santoriello said Friday.
Santoriello said officials want to conduct "multiple tests" before they lift the ban instituted Thursday after E. coli was detected in a district well.
"We want consecutive samples, two days in a row, three days in row, that come back clean," Santoriello said. "I don't want to send anything to customers that isn't good." The addition of chlorine, he said, ensures the water is clean.
During weekly testing Wednesday, a sample from one of 20 testing locations detected bacteria. As required, all 18 district wells were tested and a sample Thursday from well No. 16 tested positive for E. coli, Santoriello said.
The well, 650 feet deep and installed in 1994, was immediately taken offline, chlorine was added and a boil-water alert issued to the district's 40,000 customers.
Santoriello said he was "baffled" that bacteria was found in the well, and said officials will try to find the source.
Residents are advised to bring water to a rolling boil, let it boil for one minute, and cool before drinking or using for food preparation. The presence of E. coli indicates possible contaminated water supply by human or animal waste. Consuming E. coli-contaminated water can cause diarrhea, cramps, nausea and headaches.
Some residents were upset they did not know about the alert until late Thursday. Santoriello said the district's protocol for alerts is to first contact radio and television outlets, followed by print media, then distribute fliers to residents and by word-of-mouth.
"The board . . . and myself are going to see what we could do better," he said. "We felt we got it under control in a quick fashion. I had members of my staff and members of the local fire departments . . . out all over until midnight. But it's a big district."