The Denver Metroplex plan began in 2014 and includes six airports from Fort Collins to Centennial, including the Denver International Airport, Colorado Politics reported Thursday.

“The comprehensive project will use satellite navigation to move air traffic more safely and efficiently through the area,” the administration said in a statement. “It includes 29 new routes and modifications to 15 existing routes.”

The changes are essential for NextGen, an air traffic control system that requires new instrument flight procedures and technologies, department officials said.

The announcement came after months of study and protests.

The agency released an environmental study that said there would be no significant impact from the changes, concluding that farmland, natural resources, light pollution, water, and the health and safety of children would see no effect from the new flight paths.

Arapahoe County opposed the initiative arguing the administration often misinterprets or ignores potential increases in noise and pollution. The county and two other jurisdictions filed a petition against the agency last week asking a federal judge to review its environmental findings.