Eastern Iowa Airport ditches geothermal plans out of PFAS concerns

The Eastern Iowa Airport has abandoned plans to use geothermal heating and cooling for the final phase of its expansion after failing to get a permit to dig a new well field because of regulators’ concerns about “forever chemicals” at the site.

Background

The airport last year started the final phase of a 10-year renovation. Phase 4, projected to cost $68 million, includes adding 32,000 square feet with four additional jet bridges, a larger patio that serves alcohol and an indoor pet relief area.

Airport leaders wanted the new addition to include geothermal heat — just like the Phase 3 expansion of Terminal B completed in 2019.

They applied Aug. 14 to Linn County for a permit to expand a geothermal well field with 105 new wells, each 300 feet deep. The wells aren’t for accessing water. Instead, a closed loop of tubes is installed underground, where the Earth’s consistent temperature — about 65 degrees in Eastern Iowa — can be used to heat or cool a building.

Geothermal heat pumps can cut energy use and emissions up to 44 percent compared with air-source heat pumps and 72 percent compared with standard air-conditioning units, the U.S. Department of Energy reported.

The Iowa Department of Natural Resources raised questions about perfluoroalkyl and polyfluoroalkyl substances, or PFAS, found in private wells around the airport. Firefighters at airports and military bases were required for decades to use foam with PFAS, which helped control fuel fires.

Called “forever chemicals” because of how long they stay in the human body, PFAS may harm growth and development and affect reproduction, thyroid function, the immune system and liver function, the U.S. Centers for Disease Control and Prevention reported.

Last fall, the airport worked with the Iowa DNR to drill two test wells and test water for PFAS. In one well, no PFAS were detected, airport Director Marty Lenss said in November. In the other well, the levels were below a standard for safe drinking water that the federal government is expected to set, Lenss said.

The airport shared those results with the Iowa DNR and were waiting for approval so it could move forward with drilling before the ground froze solid in December.

What’s happened since

Airport officials have decided to omit the well field expansion from the project, which means the new addition will be heated and cooled with traditional boilers and chillers housed in a small physical plant, spokesperson Pam Hinman said.

“After further internal discussions, we have opted to go a different route; this will not require any permit,” Hinman said in an email. “We have determined this is the best course to help ensure the project is delivered on time.”

The goal is to finish renovations by spring 2025.

Hinman said she did not yet know how the changes will affect the cost of the project.

Meanwhile, the airport is slated to submit a report to the Iowa DNR by April showing results of further testing of wells, groundwater and soil for PFAS.

Comments: (319) 339-3157; erin.jordan@thegazette.com2222