Reuters: The president of the Navajo Nation said that US environmental regulators approved a final air permit on Thursday for a proposed 1,500 megawatt coal-fired power plant in New Mexico, considered an important step in moving the US$3 billion to US$4 billion project forward. Navajo Nation President Joe Shirley has waited more than four years for the permit for the Desert Rock plant from the US Environmental Protection Agency. “We know that there will continue to be challenges, but …