The US Federal Aviation Administration (FAA) has awarded Indiana's South Bend International Airport (SBN) a grant of more than $6.1m to reduce emissions and improve air quality.
The FAA is providing the funds through its Voluntary Airport Low Emissions programme (VALE) and Airport Improvement Program (AIP).
Out of the total grant, more than $5.6m will be used to install a geothermal heating and cooling system at the airport.
Making use of relatively constant temperature below the earth's surface, the geothermal heating and cooling systems will help in replacing the ageing heat pump system that has been at the airport for the past 20 years.
A total of $487,754 have been awarded by AIP for the costs associated with the facility design modifications needed to construct the federal inspection station (FIS) and general aviation facility (GAF). This brings the airport a step closer to providing services for international commercial passenger and general aviation traffic.
Commenting on the funding, SBN executive director Mike Daigle said: "Any time we are awarded grant money, there is reason to be pleased.
"We thought outside the box when applying for these grants. While each of these projects qualified for funding under the grant guidelines, we are told this is the first time the FAA has awarded VALE funds for this type of geothermal project."
The airport plans to begin work on the geothermal project later this month.
The projects will go out to bid once pending approvals from US Customs and Border Protection on the design of the FIS and GAF are accepted. Construction is expected to begin in early 2015.