This report describes sustainability, its benefits, and identifies different applications in traditional airport construction and everyday maintenance projects. An accompanying CD-ROM, CRP-CD-125, provides an Airport Sustainability Assessment Tool (ASAT) that complements the guidebook and can be used to: assist the user in identifying sustainability initiatives that might be most applicable to an airport project, given certain criteria that the user sets; obtain more information about specific strategies; and learn about sustainability initiatives that have been implemented at other airports through case studies. The guidebook and the CD-ROM will be useful to environmental managers, planners, and consultants interested in adopting sustainability strategies and initiatives into their next airport project--