The city of Muscatine, Iowa is using coal ash on its streets to conserve salt this winter, a development that has some people concerned about pollution.
The material, known as bottom coal ash, is waste from burning coal. Muscatine Power and Water is providing it to the city for free.
The Muscatine Journal reports some people have expressed concern about whether the coal ash is safe to use on city streets. The material is known to contain levels of heavy metal pollutants, including lead and mercury.
State and utility officials say the city and company have been following state laws that govern the use of coal ash. Muscatine Power and Water says the utility is actively finding ways to recycle coal ash to save on landfill space.