GILLETTE, Wyo. - An orange cloud that drifted over a part of Campbell County last week is nothing unusual.
The cloud was a result of cast blasting last Thursday at Rawhide mine owned by Peabody Energy.
Cast blasting is a blasting technique used for removal of the top soil that covers the coal seam. The technique blasts the top soil more energetically to move it across and into the pit void created by the coal being removed.
About 95 percent of the cast shots in the Powder River Basin produce visible nitrogen oxides fumes, which are toxic.
State Environmental Quality Department spokesman Keith Guille (GILL) tells the Gillette News Record (http://bit.ly/VDvoQL) that mines don't blast when conditions could cause the fumes to drift near houses or other inhabited buildings.