PFAS in Brownfield Redevelopment: How Colloidal Chemistries Create a Clearer Path Forward

Brownfield redevelopers face increasing complexity as PFAS contamination—often from past Aqueous Film Forming Foams (AFFF) use, metal finishing, or industrial processes—introduces new regulatory, financial, and liability concerns. With states and federal agencies tightening standards, developers and consultants find themselves asking the crucial question:

“If PFAS is present, can this project still move ahead?”

Increasingly, the answer is it depends. The good news is that there are , thanks to PFAS in situ sequestration technologies like ColloidalChem™, which help reduce uncertainty, control plume behavior, and support redevelopment timelines.

Why PFAS Complicates Redevelopment

One of the primary concerns with PFAS is its high mobility as it moves quickly with groundwater, making it difficult to contain. Unlike many other contaminants, PFAS is exceptionally persistent, resisting natural degradation for decades and therefore remaining in the environment far longer than other substances. Furthermore, regulatory agencies set PFAS cleanup standards at ultra-low, parts-per-trillion levels, which presents additional challenges for remediation efforts.
 
PFAS contamination rarely occurs in isolation and is often found alongside other pollutants such as metals, petroleum products, or solvents, complicating cleanup strategies. Adding to the complexity, states our outpacing federal regulatory agencies, including the EPA, are lowering acceptable limits while accelerating enforcement actions. This heightened regulatory pressure demands more robust and innovative approaches to redevelopment these sites not only in terms of costs but minimizing risks of future litigation.

How ColloidalChem Supports PFAS-Impacted Brownfields

ColloidalChem, a colloidal carbon-based injectable amendment, provides a practical and redevelopment-friendly solution by immobilizing PFAS in place and limiting off site plume migration.

Key benefits for redevelopment sites: ColloidalChem enables rapid reduction of PFAS concentrations in groundwater and offers high distribution efficiency over larger size particles offered with other amendments. Perhaps most importantly, it provides long-term plume control stability without the need for ongoing aboveground pump and treat systems. This technology also causes minimal surface disruption, making it compatible with active or planned construction, and it reduces lifecycle costs compared to many conventional remediation options with higher CAPEX and O&M Costs.

What to Evaluate Before Selecting a Colloidal PFAS Remedy

Before deploying colloidal sequestration, site teams conduct a thorough assessment of several critical factors. First, they need to consider soil type and heterogeneity, as these characteristics directly affect the injection process and the treatment's distribution throughout the site. The range of PFAS concentrations for both long chain and short chain PFAS present, along with any co-contaminants, must also be evaluated to ensure the remedy is tailored appropriately.

Another important cost and injection consideration is the depth and thickness of the treatment zone. The velocity of groundwater flow is also assessed, since it influences the risk of contaminant migration and also the longevity of treatment. Finally, logistical aspects of redevelopment, including site access, remediation sequencing, and construction constraints, must be factored into the planning process.

Practical Results: PFAS + Hex Chrome Pilot Test

At a former metal-plating facility, now a Superfund site, a pilot project highlighted the effectiveness of ColloidalChem +ISCR™. ColloidalChem + ISCR is a combined in situ remedy that provides both carbon sequestration and chemical reduction. In this case, PFAS and Hexavalent Chromium respectively. The site team performed direct-push injections across a heterogeneous lithology, demonstrating not only the chemistry efficacy but it’s distribution in more complex subsurface conditions.

Following treatment, concentrations of PFOS, PFHxS, and hexavalent chromium were temporarily reduced below the maximum contaminant levels (MCLs), meeting regulatory requirements.Full scale design and implementation will ensure these reductions are sustainable.

Overall, this case demonstrates the value of colloidal sequestration as an effective solution for mixed-contaminant sites facing regulatory scrutiny.

When ColloidalChem Works Best as Part of a Broader PFAS Strategy

Remediation sites with high groundwater velocity conditions can achieve better outcomes by combining ColloidalChem with other treatment technologies. Integrating these approaches provides greater flexibility and enhances the effectiveness of the overall remediation strategy.

For example, pairing ColloidalChem + Anchor™ is ideal for intercepting plumes or treating high-flow groundwater zones. This versatility allows realizing the benefits of ColloidalChem which is highly mobile due to its low micron particle size, but also keeping it contained within the treatment barrier where treatment is occurring.

PFAS is thought to be a barrier to Brownfield redevelopment, but this generalization is nolonger the case. With proven remedies like ColloidalChem and the right site conditions environmental teams can reduce uncertainty, control risk, and keep redevelopment timelines intact. 

Want to learn more about PFAS and Brownfields? Watch our webinar recording on demand, PFAS and Brownfields: Can Your Redevelopment Project Move Forward?

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About the Author

Eliot Cooper

Remediation Technology Expert
[email protected]

In this role, he helps clients design efficient and cost-effective remedies using high resolution site characterization (HRSC) and a vast array of remediation options. His specialty is finding the right combination of tools and technologies for complex sites, and ensuring every step of the remediation process is optimized to achieve results.