PORTLAND, Maine (NEWS CENTER) -- The Portland Jetport is getting an upgrade, and making some changes to increase flight safety and sustainability.

The airport unveiled its sustainable airport master plan project that details short term and long term development plans.

Some of the most immediate upgrades include expanding the airport's terminal apron to accommodate new planes with longer wingspans. Later projects include runway maintenance, adding a customs facility, and increasing safety by adding bypass taxi areas.

The 20 year plan will cost an estimated 312 million dollars, with the funding coming from airport user fees and revenues from things like parking and rental cars. Officials say no Portland taxpayer money will be used.

The Jetport produces a master plan like this every ten years. Airport officials say this one is especially exciting because of its focus on sustainability.

The proposal will be presented to the Portland City Council in April for workshops.

The full master plan is available here: http://bit.ly/1nm4a4E