Contaminants such as salts, metals, and radioactive elements found in the runoff were at levels higher than what’s considered healthy for people and the environment.

Last year, Pennsylvania and West Virginia contributed nearly half of the more than a billion gallons of frack waste that were injected into underground wells in Ohio.

Pennsylvania has ended what had become common practice for municipalities that wanted to suppress dust on unpaved roads. A study found that some chemicals wash away during rain — and that when the road dries, contaminants can get into the air.