Becca Vermace & Katie Wolohan

This presentation will discuss the results of the “Evaluation of Current Alternatives and Estimated Cost Curves for PFAS Removal and Destruction from Municipal Wastewater, Biosolids, Landfill Leachate, and Compost Contact Water” report prepared for the MPCA and associated publication in Water Environment Research, “Is Removal and Destruction of PFAS from Wastewater Effluent Affordable?”.

Breaking the PFAS Cycle

Per and poly-fluoroalkyl substances (PFAS) are continuously added to the environment. The environmental persistence of PFAS means that PFAS entering soils, groundwater, surface water, and the atmosphere will continue to cycle forever until actively removed and destroyed. Future work to address the human and environmental health impacts of PFAS should focus on breaking this forever cycle. This includes reducing the amount of PFAS added to the environment (the focus of this study), reducing cross-media transfer of PFAS, and destroying PFAS.

Municipal waste streams are a notable route for PFAS to enter the environment. This presentation focuses on removing and destroying PFAS from municipal water resource recovery facility (WRRF) effluent. While PFAS routed to biosolids is also a significant route of environmental PFAS inputs, we are not focusing on that here.

Importance of Affordability

The Environmental Protection Agency (EPA) defines affordability for wastewater services as staying below 2.0% of median household income. If additional costs are not subsidized by the government, they would need to be paid by utility ratepayers and resulting rates above the 2.0% guideline are likely to cause economic hardship. This analysis examines the affordability of current wastewater rates for three theoretical Minnesota communities (0.1, 1, and 10 MGD WRRFs) and compares them to future wastewater rates if PFAS treatment and destruction were implemented at the WRRF.

Costs and Affordability Estimates

This study considered a broad list of technologies for their ability to remove both short-chain and long-chain PFAS and their current commercial availability. Minnesota WRRFs would require the installation of tertiary treatment to meet influent quality standards for most commercially available PFAS treatment unit operations. This study presents costs for retrofit to tertiary treatment, followed by lead-lag granular activated carbon (GAC) adsorption vessels for primary PFAS removal, followed by lead-lag anion exchange (AIX) vessels for polishing prior to discharge. Costs include the destruction of PFAS via out-of-state, high-temperature incineration of sorption media.

PFAS treatment and destruction at municipal WRRFs is unaffordable, regardless of community size, even with a 50% government subsidy. The unaffordability is about 5 times greater for small communities than for larger communities and would be larger if PFAS biosolids management costs were included.