A federal judge has declined to dismiss a lawsuit brought by environmental groups against the Tennessee Valley Authority. The Commercial Appeal reports the ruling by U.S. District Judge Thomas Parker means the case will proceed. The environmental groups argue the auto-renewing, 20-year contracts TVA has offered power companies violate the law governing the federal government-owned utility. The groups say the length of those contracts would allow TVA to drag its feet on moving away from carbon-based sources of energy and stymy its potential efforts to reduce carbon emissions. TVA says the long-term power agreements don’t govern its power supply choices.