FLAGSTAFF, Ariz. — The U.S. Environmental Protection Agency (EPA) announced Feb. 11 three contract awards for cleanup efforts at more than 50 abandoned uranium mine sites on and around the Navajo Nation, including at least 10 sites in Arizona and others in …FLAGSTAFF, Ariz. — The U.S. Environmental Protection Agency (EPA) announced Feb. 11 three contract awards for cleanup efforts at more than 50 abandoned uranium mine sites on and around the Navajo Nation, including at least 10 sites in Arizona and others in …