The South Dakota Public Utilities Commission voted unanimously to turn down Summit Carbon Solutions' application to build a 469-mile (755-kilometer) in-state route — part of an intended $5.5 billion, 2,000-mile (3,220-kilometer) pipeline network through five states. The decision complicates an already complex process for Summit Carbon Solutions as it seeks similar authorization in other states amid opposition from landowners and environmental groups. The proposed network would carry planet-warming carbon dioxide emissions from more than 30 ethanol plants in Iowa, Minnesota, Nebraska, North Dakota and South Dakota for permanent underground storage in central North Dakota.