Sioux City Air National Guard Base

Sioux City Air National Guard Base is a military airfield located at Sioux Gateway Airport in Sioux City, Iowa. The installation was established in 1942 as Sioux City Army Air Base and opened in July of that year, serving during World War II as a training center for B-17 and B-24 bomber crews. In the 1950s it operated as an Air Defense Command fighter-interceptor base, and from 1959 to 1968 it functioned as a radar control center with a regional air defense data system. The Iowa Air National Guard assumed host status in 1968, and the base is today home to the 185th Air Refueling Wing, which operates KC-135 Stratotanker aircraft and provides aerial refueling and mobility support to the Air Force.

As with many airfields where firefighting foam was used for decades, the base has been associated with concerns about potential exposure to per- and polyfluoroalkyl substances detected in groundwater. A military report released in 2019 raised concern about these chemicals at the site, and a city utilities official later expressed confidence that the base was a likely source of contamination affecting local water supplies.

1. AFFF (aqueous film-forming foam): AFFF is a firefighting foam historically used at military airfields to suppress fuel fires during training and emergencies. At Sioux City, AFFF used in connection with the 185th Air Refueling Wing has been identified as the suspected source of fluorinated compounds found in area groundwater. Because the foam contains these persistent chemicals, its repeated use has been associated with concerns about long-term contamination of soil and water.
2. PFAS (per- and polyfluoroalkyl substances): PFAS are a large family of manufactured chemicals valued for their resistance to heat, water, and oil. Testing at the base reportedly found PFAS in groundwater at concentrations more than 100 times the U.S. Environmental Protection Agency health advisory level in effect at the time, with measurements reaching several thousand parts per trillion. Some PFAS have been associated in research with concerns about certain cancers and other health effects, though findings vary.
3. PFOS (perfluorooctane sulfonate): PFOS is one of the most studied individual PFAS compounds and was a common ingredient in older firefighting foam formulations. It was among the substances detected in groundwater connected to the base, and a nearby municipal drinking-water well tested by the Iowa Department of Natural Resources showed PFOS as part of the PFAS measured there. PFOS has been the subject of ongoing study regarding potential human health concerns.
4. PFOA (perfluorooctanoic acid): PFOA is another widely studied PFAS compound associated with industrial use and firefighting foam. It was reported among the prominent PFAS identified in testing related to the base and the nearby city well. As with related compounds, PFOA has prompted concerns about potential exposure, and federal agencies continue to evaluate its health implications.

The Sioux City Air National Guard Base is not listed as a federal Superfund site on the National Priorities List. Investigation of PFAS at the installation has been handled through the Department of Defense environmental review process, with the Iowa Department of Natural Resources independently testing a municipal well located roughly a mile and a half from the base. Officials have indicated that further testing and study are needed to characterize the extent of any contamination and movement of the chemicals offsite.

Veterans, Guard members, and family members who served or lived near this installation may wish to stay informed as monitoring continues. Anyone with questions about possible exposure and related benefits is encouraged to speak with the U.S. Department of Veterans Affairs, which can provide current guidance based on individual service history.