PLYMOUTH, Box Elder County – Local health authorities have ordered residents of Plymouth to boil their water after E.coli bacteria was found in the city’s water supply.

The city’s water system has been flushed and levels of chlorine added to the water have been raised, said Plymouth Mayor Hal Mason on Saturday.

Mason said the town of 400 was awaiting test results of water samples collected Saturday, which could be available Sunday. The city’s water supply will be tested for the next 10 days, he said.

The water may have become contaminated when a water line broke but city workers are still attempting to determine a source of the contamination.

E. coli bacteria normally live in the intestines of people and animals. Most strains of the bacteria are harmless but some can be pathogenic, which means they can cause illness such as diarrhea or illness outside of the intestinal tract, according to the Centers for Disease Control.

Heating water to a rolling boil for five minutes will destroy disease-producing organisms, a Bear River Health Department advisory said.