Nashville International Airport's Water Source Geothermal Project Receives Envision Silver Award For Sustainable Infrastructure

The Water Source Geothermal project implemented at the Nashville International Airport in Tennessee is the recent recipient of the Envision Silver award from the Institute for Sustainable Infrastructure (ISI). The Envision system rates sustainable infrastructure projects across the full range of environmental, social, and economic impacts.

In 2010, the Metro Nashville Airport Authority (MNAA) was selected as one of only 10 airports in the United States to take part in the Federal Aviation Administration’s (FAA) Sustainable Master Plan Pilot Program. The MNAA was selected for this program for its demonstrated leadership in implementing sustainability initiatives, and promotion of water conservation, energy efficiency, social well-being, and community involvement. The MNAA’s Master Plan included the implementation of this water source geothermal project to meet the airport’s cooling and irrigation needs. The plan was broadly supported and approved by the Board of Commissioners, which is a diverse group with three representatives from the business and finance community, two pilots, two neighborhood representatives, one engineer, one lawyer, and the Nashville Mayor.

Companies involved in the project include Garver, Blakley Construction Services, and Energy Systems Group—all of whom worked in close collaboration with MNAA to deliver the sustainable infrastructure initiative.

“This is a remarkable project for its scope, ingenuity and efficiency,” said Rob Wigington, president and CEO of MNAA. “The Airport Authority is committed to making sustainability an integral part of our business model. Not because sustainability is easy—rather, it is often a complex process—but because the benefits to our airports, the region and our environment are overwhelmingly positive. This historic project reduces our electricity usage and potable water consumption, which equates to substantial annual utility savings. This is the very essence of sustainability.”

As a collaboration between ISI and the Zofnass Program for Sustainable Infrastructure at the Harvard University Graduate School of Design, the Envision system rates the impact of sustainable infrastructure projects as a whole. The ISI Envision system measures sustainability in five categories: Quality of Life, Leadership, Natural World, Resource Allocation, and Climate and Risk. These key areas contribute to the positive social, economic, and environmental impacts on a community.

Key sustainable accomplishments of the Water Source Geothermal project at the Nashville International Airport include:

Resource Allocation: The quarry lake, once considered a liability for the Airport Authority, was turned into an opportunity, and reconceived as a beneficial resource. By using lake plates to target a depth in the water that remains 50 degrees Fahrenheit year-round, the Airport Authority is able to generate chilled water for the cooling system. More than $430,000 in electricity costs per year are expected in savings due to the implementation of this geothermal system. This represents a more than 50% improvement over the baseline that was established for this project. "Harnessing the cooling effect of the quarry water created a renewable, sustainable energy source," said Ryan Sisemore, director of Garver Aviation's East Region. "A project like this encourages innovation in the way we create solutions."

In addition to significantly reducing electrical demand, the project also reduces potable water consumption—by more than 30 million gallons. Prior to the implementation of this project, the Airport’s irrigation and cooling systems relied on water from Metro Water Services, which pulls water from the Cumberland River for treatment and distribution. By contrast, the Water Source Geothermal System is a closed loop system that is able to meet the cooling requirements of the airport’s terminal building by relying on the quarry lake’s ability to chill water via lake plate heat exchangers. Through this system more than 21.1 million gallons of potable water used in the airport’s cooling towers are saved. Additionally, by harvesting rainwater, which collects in the quarry and pumping to the irrigation system, more than 13.1 million gallons of potable water used for irrigation is saved. Both efforts significantly reduce the strain on the municipal water supply.

Leadership: The Metro Nashville Airport Authority recognizes that the travelling public demands an excellent environment to travel through. As the community’s “front door” for more than 12 million people travelling through the airport each year, MNAA sees the project as a valuable opportunity to promote sustainability and the community more broadly. It is implementing several educational programs aimed at travelers, with plans to roll out a Green Screen in the terminal building to continue educating travelers regarding the sustainability measures put in place.

In 2015, MNAA was awarded the Governor’s Environmental Stewardship Award, which recognizes the Airport Authority’s “exceptional voluntary actions that improve or protect the environment and natural resources with projects or initiatives not required by law or regulation.”

The project team overcame significant challenges to securing funding for this project. To overcome state or federal funding barriers, the project team targeted energy efficiency project funds that were set aside in the FAA's 2012 Reauthorization Act. The team worked with the FAA's headquarters in Washington, D.C. to navigate the regulatory approval process. The successful grant acquisition, as well as the energy performance contracting for this project, has opened the door for more energy efficiency projects to be implemented at other airports across the country demonstrating significant leadership in sustainability.

Climate and Risk: The Water Source Geothermal project will significantly reduce the airport’s dependency on its natural-gas fired boilers, which use on average 39,700 therms of natural gas per month. Emissions associated with the use of these boilers is significant, but the Water Source Geothermal project will reduce emissions of carbon monoxide, nitrogen oxide, particulate matter of both 10 and 2.5 micrometers or less in diameter, sulfur dioxide, and volatile organic compounds—all of which contribute to poor air quality.

“The Water Source Geothermal project at the Nashville International Airport is an innovative solution to meet the airport terminal’s irrigation and cooling needs in a sustainable manner,” said ISI President and CEO, John Stanton. “This initiative will benefit not only the airport’s bottom line, but will serve as an excellent example of sustainability for the thousands of people who travel through the airport each year. ISI is very pleased to present this project with the Envision Silver award for sustainable infrastructure.”

To learn more about the Implementation of Water Source Geothermal project, please visit https://garverusa.com/iq/201683/163/bna-geothermal-cooling-system.

About MNAA

The Metropolitan Nashville Airport Authority (MNAA) was established in 1970, and owns and operates Nashville International Airport (BNA) and John C. Tune Airport (JWN). With more than 12.9 million passengers visiting each year, Nashville International Airport is the fourth fastest growing airport among the top 50 airports in North America. BNA serves 440 daily flights to more than 50 nonstop markets. It is now the 33rd busiest airport in the U.S. MNAA is an Equal Opportunity Employer. For more information, visit http://www.flynashville.com.

About Garver:

Garver is a multi-disciplined engineering, planning, and environmental services firm committed to quality practices, progressive methods, and honorable relationships. Our clients' trust is the cornerstone of our business, and we adopt their visions to deliver projects founded on sound designs, creative solutions, cost-effective services, and first-class customer care. With engineering services dating back to 1919, Garver has nearly a century of service in providing clients with consulting expertise. Garver has 18 offices in nine states, and our headquarters are based in North Little Rock, Arkansas. We provide services for transportation, aviation, water, energy, industrial, development, federal, survey, and construction management projects.

About Blakley Construction Services:
Blakely Construction Services was founded by Michael Thomas and Lloyd Soeters in 2010. They are a Heavy/Civil General Contractor serving in the Private Industrial and Municipal Water and Sewer Markets. Their goal is to provide customers with professionally managed construction projects. For each project, they pre-plan activities, communicate plans to the engineer and owner, and plan the activities again. Planning and communicating are the keys to success in their business. Many contractors can build a project, but at Blakley their mission is to build projects that make everyone’s job easier and more enjoyable.

About Energy Systems Group:
Energy Systems Group is an award-winning energy services provider, specializes in developing sustainable energy solutions which allow building owners to maximize their energy efficiency and operational performance, while reducing their carbon footprint. Since 1994, the development of longlasting and trusting relationships continues to be the foundation of their business. Through its core business of performance contracting and its extensive network of utility partnerships, ESG provides innovative solutions for the modernization of buildings and energy infrastructures in the government, education, healthcare and commercial sectors. ESG also designs, builds and operates landfill gas facilities and cogeneration plants and offers a full range of waste-to-energy, solar, wind, and geothermal technology solutions.

About ISI Envision:
Envision is the product of a joint collaboration between ISI, which was founded by three national engineering associations: American Society of Civil Engineers, American Council of Engineering Companies, and American Public Works Association, and the Zofnass Program for Sustainable Infrastructure at Harvard University Graduate School of Design. For more information, visit http://www.sustainableinfrastructure.org/.