Portland International Airport has secured a $331,653 Federal Aviation Administration (FAA) grant from the US Transportation secretary Anthony Foxx to cut down emissions to improve air quality.
The airport will use alternative fuel vehicles through the FAA's Voluntary Airport Low Emission (VALE) programme, which has been designed to reduce sources of airport ground emissions in areas of marginal air quality.
The grant will be used to purchase six compressed natural gas buses that will transport airport passengers and employees from the terminal to parking and rental car facilities.
Said to be part of the airport's programme, the latest project helps in reducing vehicle emissions within the airport footprint.
Foxx said: "Today's announcement supports President Obama's efforts to reduce carbon pollution and increase the deployment of cleaner, alternative fuel technologies.
"It complements the broad efforts across the FAA to expand the development and use of new technologies for aviation fuels that will benefit human health and the environment."
Initially, the VALE programme was implemented by the FAA in 2005 to help airport sponsors meet their air quality responsibilities under the Clean Air Act.
The programme enables airport sponsors to use Airport Improvement Program (AIP) funds and passenger facility charges to purchase low-emission vehicles, refueling and recharging stations, gate electrification and other airport-related air quality improvements.
FAA Administrator Michael Huerta said: "This project will allow the airport to realise immediate emission-reduction benefits for the airport and surrounding communities."
The VALE programme, which supports the objectives of the President's Climate Action Plan, helps airports to reduce ozone emissions annually by approximately 466t.
Building on efforts to address climate change, the programme also supports innovation in clean energy, including investments in advanced vehicle and fuel technologies, public transit and rail under the Recovery Act.