PNNL

Four environmental remediation researchers from Pacific Northwest National Laboratory (PNNL) were invited to speak at the Spring 2025 Federal Remediation Technologies Roundtable (FRTR), a premier interagency forum that advances technology solutions for environmental cleanup. Their selection underscores PNNL’s leadership in subsurface characterization, sampling design, and advanced monitoring at complex contamination sites.

The FRTR public meetings focused on the theme Innovative Approaches to Characterization and Survey of Complex Mixtures of Contaminants in Support of End-State Regulatory Compliance. On May 13, data scientist Jen (Huckett) Willis presented recent and planned enhancements to PNNL’s Visual Sample Plan (VSP)—a decision-driven software tool that helps environmental professionals design statistically defensible sampling strategies. On May 14, environmental engineer Rob Mackley, lab fellow and chief geophysicist Fred Day-Lewis, and computational scientist Judy Robinson shared how PNNL is deploying advanced hydraulic and geophysical tools to support characterization and remedy optimization efforts at the Hanford Site.

Tackling subsurface complexity

At legacy sites like the Hanford Site, where contamination extends across vast areas and through deep, heterogeneous vadose zones, conventional sampling methods can fall short. Mackley, Day-Lewis, and Robinson outlined PNNL’s work to better understand contaminant distribution by integrating vertical flowmeter logging with sampling in long-screened wells. This approach improves the resolution of contamination vertically within thick aquifers and supports targeted pump-and-treat extraction strategies that will result in decreased cleanup timeframes.

“Long-screened wells present both a challenge and an opportunity,” Day-Lewis said. “By combining flowmeter data with contaminant sampling, we can get a much clearer picture of where contaminant mass is concentrated—and how to target it more effectively.”

They also highlighted how geophysical methods—such as electrical resistivity tomography and induced polarization—can be used to track soil flushing and reactive amendment processes. When coupled with simulation models, including machine learning–enhanced reactive transport tools, these approaches offer new insights for performance monitoring and remedy evaluation.

This body of work is helping Hanford project teams identify high-concentration zones, characterize plume behavior, and adapt pump-and-treat cleanup strategies.

Tools for smarter sampling

Willis’s presentation spotlighted the evolving capabilities of the VSP software, which continues to serve thousands of users across regulatory agencies and cleanup programs. With recent enhancements to support subsurface survey design, anisotropy estimation, and analysis of continuously collected data, VSP helps decision-makers plan efficient, statistically valid surveys even in complex radiological settings.

“We’re constantly evolving VSP to meet the needs of today’s environmental decision-makers,” said Willis, who specializes in statistical survey design, analysis, and software development. “Whether it’s integrating 3D subsurface complexity or handling data collected by autonomous systems, our goal is to make sure end users have the tools to make confident, defensible decisions.”

Willis also described how VSP’s built-in visualization tools and automatically generated reports improve transparency and defensibility—critical for regulatory compliance. The software remains central to training efforts and field deployment, particularly in coordination with the Department of Energy (DOE), Nuclear Regulatory Commission, and Environmental Protection Agency cleanup missions. PNNL received the 2024 Federal Laboratory Consortium for Technology Transfer (FLC) Impact Award for VSP. The award honors FLC member laboratories whose technology transfer efforts have made a tangible and lasting impact on the populace or marketplace across local and global scales.

Collaboration and support

These FRTR presentations reflect the strength of cross-program collaboration within PNNL’s Environmental Management sector. Work presented by Mackley, Day-Lewis, and Robinson is funded by the DOE Hanford Field Office under the Deep Vadose Zone program and by the DOE Office of Environmental Management’s Technology Operations Office. Since its beginning, VSP development has been supported by multiple agencies, most recently including the Nuclear Regulatory Commission, DOE, and the U.K. Department for Environment, Food and Rural Affairs (DEFRA).

By sharing practical, field-tested solutions with national audiences, this research team represents PNNL’s ability to provide scientific and technological solutions for the toughest subsurface challenges. These contributions also lay the groundwork for discussions at the 2025 Global Summit on Environmental Remediation in November, where complex site characterization and cleanup are central themes.