DEQ removes 5 Riverton pollution cleanup devices

State environmental officials have removed groundwater cleanup systems at five locations in downtown Riverton. Several more of the systems remain in place around the city. Most are on the sites of former gasoline stations. The devices pump air underground to break down hydrocarbons in the water table. Mark Thiesse with the state Department of Environmental Quality says monitoring shows that pollution in the ground around the five devices has decreased. He says DEQ turned off the devices two years ago after pollution levels stopped decreasing. The state agency decided to remove the five devices after noting no increase in pollution concentrations since then.