The Environmental Protection Agency requires two monthly bacteria water tests, and Smithfield's second test for August came back on Monday positive for E. coli.

The EPA is now requiring another round of testing, one of which includes the source of the water. Smithfield gets its water from Jefferson County, and the county gets water from the town of Brilliant.

Debra Prim, an environmental specialist with the EPA, said, "It doesn't mean that Brilliant's water supply is contaminated with bacteria. It doesn't mean that Smithfield's water is contaminated with E. coli. It could be that it's just a sampling error. It could be that the person who collected the sample cross contaminated the sample bottle."

Water department officials said workers who take the samples also work in the sewage department, and Prim said that it's possible that cross contamination came from someone's hands.

EPA officials said Brilliant's water tests for August came back clean and it appears the incident is limited just to Smithfield. New test results are expected on Wednesday.

Customers in Smithfield should boil their water until further notice and people there should also wash produce with water that has been boiled.

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