What You Need to Know Before Choosing a Remedy for Your Brownfield Site

04/01/26

The expense of investing in redeveloping brownfield sites can be high. These properties are often abandoned, contaminated, and blighted, making them challenging for communities and developers to turn around.

However, with the support of federal and state funding and sometimes a shortage of Greenfield sites in inner-cities, redevelopment is becoming a more attractive investment, and consultants are increasingly being asked by developers to identify remediation solutions that are liability limited, fast and cost efficient. While the solution will be different on every site, you can narrow down your options if you know what data to gather and questions to ask.

Defining Site Requirements

The level of clean up agreed upon by the developer and the regulatory agency will typically depend on multiple considerations. A few common ones include:

The level of contamination
Treatment goals, e.g., MCLs, Risk-based standards, MNA, Institutional Controls

Understanding the Subsurface

Accurate site characterization, including high resolution technologies, are critical for defining site goals and determining the overall remediation approach. Two tools are often helpful, especially when time is of the essence.

The Membrane Interface Hydraulic Profiling (MIHPT) allows for rapid screening, which reduces the overall investigation time with requires lower traditional samples. Often this reduces overall life cycle remediation costs.

Waterloo Aquifer Profiling System (Waterloo^APS), which allows for direct push delivered continuous, real-time hydrostatigraphic logging combined with high quality discrete sampling capabilities to define contaminant flux, which is important when considering permeable reactive barriers as a remedy. Other in-well technologies are also available.

Addressing PFAS

While current Brownfield projects primarily deal with chlorinated solvent, petroleum and hazardous metals contamination, with the federal and some state regulations addressing PFAS, these contaminants can now add to the complexity of groundwater cleanup. In addition to regulatory drivers, the risk and liability of future litigation by the impacted public can be a greater driver for action. There is still regulatory uncertainty on impacts to the property in question since these regulations are in constant flux with legal challenges from both for and against sides of PFAS regulation.

Narrowing Down Remediation Options

Two main groundwater treatment methods are trending: Pump and Treat, and In Situ Sequestration with adsorbents like activated carbon. Each has advantages and disadvantages, and the best choice depends on key factors.

Pump and Treat

The pump and treat method is often selected when hydraulic containment is necessary to control the migration of contaminants. This approach is particularly important in situations where there are high-risk receptors present, such as drinking water wells, that could be impacted by groundwater contamination. Additionally, pump and treat is typically mandated by regulatory agencies when active removal of contaminants is required to comply with environmental standards.

However, pump and treat systems for PFAS contamination have some notable drawbacks. These systems are sometimes referred to as "forever systems" because it may not be feasible to shut them down in the foreseeable future, given the persistent nature of PFAS compounds. Media disposal associated with pump and treat can be expensive, contributing to higher operational costs. Furthermore, these systems typically have a significant carbon footprint due to their energy-intensive operation.

In Situ Sequestration

In situ sequestration is most applicable to large, dilute contaminant plumes where controlling long-term costs is essential. The primary goal with this technology is to reduce contaminant flux and exposure rather than completely eliminate mass. In situ sequestration can provide interim regulatory and liability relief while new destruction technologies are developed for PFAS remediation.

The main disadvantages of in situ sequestration are its inability to destroy PFAS and its reliance on effective distribution and contact with adsorbent materials. The performance of the technology is highly dependent on how well the treatment is delivered throughout the contaminated area. Additionally, regulatory acceptance of in situ sequestration approaches is still evolving in some states, which may impact project approval and implementation.

If you’d like to learn more about the remediation technologies that are best suited for brownfields, check out our on-demand webinar, Brownfield Success: How to Select the Right Remediation Technology for Your Budget and Timeline.

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About the Author

Eliot Cooper

Remediation Technology Expert
[email protected]

Eliot Cooper is a Remediation Technology Expert. 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.