The research focused on sampling sites near wastewater treatment plants and fields where biosolids — treated sewage sludge — are used as fertilizer. Using advanced passive samplers deployed for a minimum of 20 days, researchers found that 95% of downstream sites near treatment plants showed higher PFAS levels than upstream areas. In one striking example, a site recorded a nearly 3,000% increase downstream, reaching 228.29 parts per trillion.
Seven PFAS compounds were consistently detected, including PFOA and PFOS — both now regulated at low levels under federal drinking water standards. Several sites exceeded federal health thresholds, presenting potential compliance risks and signaling possible enforcement actions ahead.
These findings highlight an urgent need for operators to re-evaluate current treatment technologies, as many traditional and legacy systems are not designed to effectively remove PFAS.
Beyond wastewater discharges, the use of biosolids in agriculture is emerging as a major secondary pathway for PFAS contamination. The study found that 80% of downstream sampling locations near biosolid application sites showed increased PFAS levels, with one site experiencing a spike of over 5,100%, hitting 106.51 parts per trillion.
The most commonly found compounds included PFBA, PFBS, PFPeA, PFHxA, and PFHpA. This poses a direct threat to agricultural operations, where contaminated biosolids could introduce PFAS into soil and crops, ultimately impacting food supply chains.
Currently, the EPA does not set federal limits for PFAS in biosolids, despite awareness of risks for over two decades. The agency estimates that around 60% of biosolids are land-applied, with nearly one-third used on agricultural land. As understanding of PFAS persistence in the environment grows, so too does the risk of long-term soil and groundwater contamination.
Farmers and agricultural producers using biosolids face potential future liability as public concern and legal scrutiny increase. Proactive monitoring and risk mitigation are becoming essential strategies to safeguard both business operations and brand reputation.
The study’s release comes at a time of heightened regulatory uncertainty. The EPA is reportedly considering revisions to national drinking water standards that could weaken protections for several PFAS compounds and delay enforcement on others.
For companies across wastewater, agriculture, and industrial sectors, the divergence between federal and state PFAS regulations creates a complex compliance environment. Industry experts increasingly advocate for class-based PFAS regulation rather than piecemeal, compound-by-compound restrictions, which have allowed harmful substitutions in the past.
In this shifting landscape, businesses that proactively assess and address their PFAS liabilities will be better positioned to avoid litigation and strengthen long-term sustainability. Transparent reporting, investment in advanced treatment technologies, and comprehensive supply chain reviews are key steps in managing these still growing risks.
