A boil advisory has been issued for two Iowa towns, Pilot Mound in Boone County and Attica in Marion County.
In Pilot Mound, infants younger than six months should use bottled water, officials said.
The city said it started pulling water from an emergency well after the primary well was unable to meet demand.
Officials said the emergency well has not been tested recently, so the water quality is not known.
Nitrate levels are also unknown, which is why infants should use bottled water only. Infants under six months of age could become seriously ill if they drink water with elevated nitrate levels.
In Attica, the Pershing Utility Corp. said it is notifying residents that a boil order is in effect on Thursday until further notice.
Officials said a water main break is the cause of the boil order.
DNR officials said that although the cities of Attica and Pershing share a water main, water pressure in Pershing did not drop so the city was not affected.
Drinking water should be boiled for one minute or more, and then allowed to cool for adults and children six months and older. Tap water can be used for bathing and similar purposes.
The city is also asking residents to conserve water.
Questions about water quality can be found by calling the U.S. EPA’s Drinking Water Hotline at 800-426-4791.