Tens of thousands of people in Michigan were under a precautionary boil water advisory Saturday after authorities discovered a water break in Metro Detroit’s largest main supply line.
Around 280,000 people in 13 communities were affected, including Rochester city, Washington Township and Chesterfield Township, according to the advisory issued by the Greater Lakes Water Authority, which initially issued the advisory for 23 communities before it lowered the number.
Two businesses, one in Greenwood and one in Imlay Township, were also affected, the water authority said in a separate statement.
“Residents should not drink the water without boiling it first,” the statement said. “Residents must bring all water to a boil for at least one minute and then let it cool before using. Boiled, bottled or disinfected water should be used for drinking, making ice, washing dishes, brushing teeth, and preparing food until further notice.”
The break prompted Michigan Gov. Gretchen Whitmer to activate the State Emergency Operations Center on Saturday afternoon.
“Our top priority right now is protecting the public health and safety of Michigan residents until this water main is fixed as quickly as possible,” she said in a statement. "We will continue to work with local officials and are prepared to offer the full weight of state resources to get the job done,” she added.
The water authority statement said the break was identified about a mile west of the Lake Huron Water Treatment Facility, causing a dip in pressure in the main supply lines.
An advisory is declared if the water pressure falls below 20 pounds per square inch, it said. A prolonged loss in pressure can result in bacterial contamination of the water system, it added.
The city of Flint, which was initially covered by the advisory, switched to a secondary water source soon after the emergency alert and was no longer at risk of contamination, city officials said in a statement Saturday.
The cause of the water break, which was unknown, was under investigation, the water authority said, adding that the advisory would remain in effect until the water is verified safe for consumption.
Officials said that once the leak is isolated, crews will open emergency connections to other mains in the system to restore partial flow.