A federal appeals court has ruled against Alcoa in its bid to speed the process of granting a federal license to operate four dams along the Yadkin River in Stanly County.

The appellate court for the District of Columbia ruled Tuesday against Alcoa's contention that North Carolina water-quality regulators improperly issued a certification that requires Alcoa to guarantee spending $240 million in improvements to the dams. The improvements, state regulators said, were needed to bring the facilities up to current water quality standards.

Alcoa's bid to continue operating the dams, which it built along the river to provide energy for a now-closed smelting plant near Badin, is opposed by state officials and by environmental groups. Gov. Bev Perdue's administration has said it could attract new jobs if it were to operate the dams, which are along a 38-mile stretch of the Yadkin River.

And environmental groups contend pollutants from the plant, which was closed for good in 2002 with the loss of hundreds of jobs, are damaging water quality in the river and its reservoirs. Environmental groups also say the public should control use of the waters.

Alcoa received a license from the Federal Energy Regulatory Commission in 1957 to operate the dams, but the license was good for 50 years and has expired. The company says the dams and their energy-generating capacity are worth about $500 million.

State regulators say Alcoa's dams do not meet water quality standards because they draw water from deep below the surface. That water has low dissolved oxygen levels, regulators say.

Alcoa said Tuesday it will continue pursuing a new federal license, according to the Associated Press.