Eastern Iowa Airport geothermal permit hinges on PFAS testing

A monthslong wait for a permit to install underground wells for a geothermal heat system at The Eastern Iowa Airport may delay construction of the final phase of a 10-year, $120 million renovation.

Questions about perfluoroalkyl and polyfluoroalkyl substances, or PFAS, found in private wells around the airport are causing the delay.

If the airport can’t get a permit soon for a new geothermal well field, the ground may freeze and contractors won’t be able to drill the wells until spring.

“At this stage, it shouldn’t impact us in terms of delivery of the final product of the facility,” Airport Director Marty Lenss said of the goal to finish the renovations by spring 2025. But “the longer we wait, weather will become a factor and it (drilling a well field) could get pushed to spring and we may have a project impact.”

For decades, firefighters at The Eastern Iowa Airport — and airports across the country — used firefighting foam that contains PFAS. In fact, the Federal Aviation Administration until recently required airports to keep the foam on hand because of its unique properties for containing fuel fires.

High levels of PFAS have been found in residential wells near the airport. And although the airport doesn’t know if the contamination was caused by use of firefighting foam, they are doing more tests.

The airport in August submitted to the Iowa Department of Natural Resources a plan for determining the extent of PFAS contamination on the airport grounds and surrounding area. The plan said the airport would test 20 private wells, groundwater and soil for PFAS this fall and submit a final report to the Iowa DNR by April.

But meanwhile, the airport wants to move forward with the final phase of an airport renovation that started in 2014. Phase 4, which will cost $68 million, includes adding 32,000 square feet of space with four additional jet bridges, a larger patio that serves alcohol and an indoor pet relief area.

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

The airport applied to the Iowa DNR Aug. 14 to expand its geothermal well field with 105 new wells, each 300 feet deep, Lenss said.

These wells aren’t for accessing underground 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.

“As part of our overall environmental stewardship, geothermal is a very efficient heating and cooling system and one proven to be environmentally friendly,” Lenss said.

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

“Those results have been shared and now we're just waiting to see where that permit is at,” Lenss said last week.

Iowa DNR officials were scheduled to meet last Thursday with Linn County Public Health officials, but department spokeswoman Tammie Krausman said Friday no decision has been reached.

“The department will have further discussions to finalize a decision in the near future,” she said.

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