Neighbors near the We Energies power plant in Oak Creek woke up to find coal dust covering their houses and vehicles Monday morning.
A spokesperson for We Energies said via email that strong winds out of the Southeast are the likely cause.
The company can store up to 420,000 tons of coal in the outdoor storage area at the Oak Creek plant.
Greg Millard, who estimated he lives about 2,000 feet from the piles of coal, said he spent much of the day Monday wiping coal dust off of his home's exterior.
"Anything you touch, anywhere in this neighborhood, is black," Millard said.
Millard said he first complained about the coal residue over the summer.
On Monday, Millard called We Energies and asked that they send someone to test the dust around his home.
He told TODAY'S TMJ4 that representatives from the company took samples of the dust Monday afternoon and told him to expect results in about a week.
Neighbor Michelle Jeske agreed that the coal dust is not a new problem.
She said she's worried about the health impacts on her family, including her four children.
"Lung issues, that's the first thing that you think about, and that you're breathing this in," Jeske said.
We Energies said it voluntarily installed an air quality monitoring station about one mile South of the Oak Creek plant in 2016.
The results are posted online monthly and available to the public here.
Miranda Ehrlich, of the Clean Power Coalition of Southeast Wisconsin, said her organization would also like to see air quality monitored in the neighborhood to the North of the plant, where Millard and Jeske live.
The group sent a letter to We Energies calling for the additional monitoring station, among other things, in January.
"I don't think it's safe, personally," Ehrlich said.
We Energies responded in February to the Clean Power Coalition's letter.
The company said a previous air monitor in that area was removed because of low data results, and that a monitoring station located to the North of the facility was unlikely to capture the predominant winds in the area.
A spokesperson for We Energies added that, for the time being, the company will not be adding coal to the existing piles near the power plant so as to minimize coal dust.
We Energies added it is also using water technology to suppress and minimize coal dust in the area.