U.S. GAO - Aviation and the Environment: Survey of Airport Officials on Airport Environmental Issues (GAO-10-748SP, September 2010), an E-supplement to GAO-10-50

49.	What factors or circumstances, if any, have helped your airport to reduce emissions?

50.	What factors or circumstances, if any, have hindered your airport from reducing emissions?

51.	How could the Federal Aviation Administration (FAA), U.S. Environmental Protection Agency (EPA), or Congress better assist your airport to reduce emissions? Please consider the guidance provided by FAA/EPA, in addition to other aspects of FAA/EPA's role.