EPA Research Partner Support Story: Treatment options for PFAS-contaminated stormwater

Partner: Iowa Department of Natural Resources (DNR)
Challenge: PFAS-contaminated stormwater in a detention pond
Resource: Treatment options for the contaminated water
Project Period: January – March 2023

In January 2023, fire fighters used an aqueous film forming foam (AFFF) containing PFAS to extinguish a fire in Marengo, Iowa. The foam entered the stormwater collection system, resulting in an estimated twelve million gallons of PFAS-contaminated stormwater being held in a basin.

“We truly appreciate the partnership between EPA ORD and the Iowa DNR. ORD’s timely guidance was valuable and helped us to expedite the project and ensure a successful completion.” – Iowa DNR Environmental Services Division Administrator Ed Tormey

The PFAS concentrations were determined to be above levels appropriate for discharge into the Iowa River that serves as a drinking water source for many downstream communities, including Iowa City. Iowa DNR contacted EPA ORD to request help identifying options for treating the contaminated water. ORD staff met with colleagues from Iowa DNR to discuss the appropriate technologies. ORD researchers then ran models to estimate the effectiveness of the technologies, the optimal flow rates needed, and the length of time it would take to treat the total volume of water. This led to discussions on how those technologies would be implemented in the field. ORD contacted technology vendors and had meetings with Iowa DNR and the vendors discussing treatment options and remediation costs.

Ultimately, Iowa DNR chose a vendor, and a granular activated carbon (GAC) treatment system was installed. By that time, due to additional rain and wastewater treatment plant discharge, the total volume of water to be treated was approximately 13 million gallons. The stormwater retention basin was sealed off and the successful treatment of the water was completed before the rainy season, with no PFAS being detected in the water discharged to the Iowa River. This was the first time in Iowa DNR history that a large-scale, portable package plant was utilized to treat PFAS-contaminated water.