The Master Plan for the Portland International Jetport focused on the rapidly growing commercial discount airline service to the airport. During the preparation of the Master Plan, annual enplanement levels grew to record highs. This necessitated a focus on the expansion of the passenger terminal core functional areas of checked baggage screening for in-line explosive detection devices, additional departure holdroom and contact gates, as well as expanded secure screening areas. A new parking garage was also planned. The crosswind runway was planned to be extended and improved to more fully serve as a back-up to the single primary runway. Runway safety improvements were planned for each runway. The air cargo area was planned for expansion as well as a new taxiway that would reduce runway crossings. These areas were planned with consideration given to the environmental resources present at the airport, including numerous wetlands and two historic neighborhood areas adjacent to the airport, and for water quality as the airport is bounded by a creek, river, and tidal waters.