PORTLAND – Federal dollars account for the bulk of investments each year at Maine’s 36 publicly owned airports.

The Maine Department of Transportation spends about $1.5 million a year in airport improvements, and that’s used to leverage more than $25 million a year in funding from the Federal Aviation Administration, according to the Maine Department of Transportation.

The FAA gets the money from taxes and fees from airline ticket purchases.

Some of that money goes back into Maine’s six commercial airports: Portland International Jetport and Bangor International Airport, along with airports in Presque Isle, Rockland, Trenton and Augusta.

But 30 smaller general aviation airports that dot the state from Madawaska to Machias to Wells also are among the beneficiaries.

In Greenville, for example, federal grants paid for 95 percent of a $4.4 million runway improvement over the past two years, said Town Manager John Simko. The town and the state each pitched in roughly $120,000 on the project.

Next up is $300,000 in improvements for the runway apron, and there will be a similar breakdown in expenses, Simko said.

Over the next two years, the Federal Aviation Administration’s Airport Improvement Program will spend more than $57 million in Maine, said Ron Roy, director of the Maine Department of Transportation’s Office of Passenger Transportation.

Some of the bigger projects will be taxiway improvements at Auburn-Lewiston Municipal Airport and Knox County Regional Airport, Roy said.

While it may seem unfair to spend passenger fees on rural airports, the situation is similar to the gas tax and its use for highway improvements, he said.

“The income from [the gas tax] goes to support the entire highway system. You don’t say, ‘Gee, 98 percent of people use interstates, so we’re only going to spend it on the federal highway system,”‘ Roy said from Augusta.

There’s a big return for the investment. The Greenville airport pumps $3.6 million back into the economy each year, according to a report by the Maine Department of Transportation.

Overall, Maine’s 36 airports create an economic benefit of $1.5 billion each year, the report said. Of that, the state’s 30 publicly owned general aviation airports account for an economic benefit of $104 million.