Massport Port Authority, which owns and operates three airports in the state of Massachusetts, has implemented several sustainability initiatives in recent years. These including building LEED standard terminals, running fleets of alternative fuel busses, and conserving water. At Boston Logan, the airport built 20 wind turbines to offset close to 3 percent of the building’s energy needs. Other improvements included installing heat-reflecting roofting and building a runway by using environmentally friendly asphalt. The efforts have paid off, and the 31.6 million passengers that travelled through the airports have dramatically lessened the effects on the surrounding environment.