Key Technology Applications for Brownfield Site Investigations
March 6, 2025
By: Kevin Ignaszak, PE
Brownfield sites have long posed intricate challenges for environmental assessment and remediation. From the uncertainty of subsurface conditions to the legacy of improper waste disposal, these sites demand innovative approaches to ensure sustainable redevelopment. Over the years, advancements in technology have transformed the way we tackle these issues, offering greater precision and efficiency.
At Montrose, we leverage state-of-the-art tools such as LiDAR (Light Detection & Ranging) and Geophysical Surveys to address these complexities head-on. These technologies, alongside focused PCB (Polychlorinated Biphenyls) identification in building materials, form the cornerstone of our approach to resolving the unique hurdles of brownfield projects. By combining historical insight with cutting-edge methodologies, we help our clients navigate the intricate journey from environmental challenge to opportunity.
LiDAR: Revolutionizing Site Visualization
LiDAR is an optical technology that uses laser light to generate high-resolution horizontal and vertical measurements of a site’s surface and structures. One of its most powerful features is the ability to produce 3D models, which provide detailed spatial data to identify hidden contamination pathways, former waste disposal sites, and subtle topographical features.
Source: Vermont Center for Geographic Information
By analyzing LiDAR-generated 3D point cloud data, we can:
- Detect buried waste and landfills that may lack visible surface indicators.
- Identify eroding landfill caps, signaling potential contamination risks.
- Conduct vegetation and land cover analysis, helping to assess environmental impacts such as soil degradation and plant health deterioration.
A real-world example of LiDAR’s effectiveness comes from a remote, abandoned drum storage area. For reference,
- Dark blue=drums
- Light blue=no vegetation
- Light green and yellow=stressed vegetation
- Orange=normal background vegetation
Geophysical Surveys: A Deeper Look Underground
Montrose employs geophysical surveys using ground-penetrating radar and electromagnetic technology to locate buried waste, underground storage tanks, metallic debris, and other subsurface anomalies.
Ground-penetrating radar sends high-frequency electromagnetic pulses into the ground, reflecting back when encountering subsurface materials with contrasting dielectric properties. Electromagnetic technology detects variations in soil conductivity and magnetic anomalies, providing a broader understanding of underground features.
These methods are essential for evaluating the presence of underground infrastructure. In one notable case, a historical underground storage tank was believed to have been removed but lacked documentation. Although surface inspections showed no visible tank, ground-penetrating radar confirmed its presence beneath a sidewalk, enabling informed decision-making in site redevelopment.
The Overlooked Risk: PCBs in Building Materials
Polychlorinated biphenyls (PCBs) were widely used in building materials between 1950 and 1979, before being banned in the U.S. These materials, particularly paints, can pose significant risks during demolition and renovation projects. Standard asbestos and lead-based paint surveys often do not account for PCBs, leaving owners vulnerable to unexpected contamination issues.
The Importance of Proper PCB Characterization
Before demolition or renovation, proper material characterization is crucial to mitigate risks and regulatory complications. We recommend:
- Conducting bulk sampling of suspect materials.
- Further testing when PCB concentrations range between 1-50 ppm to delineate impacted areas.
- Full characterization for concentrations above 50 ppm, as these may be considered hazardous waste per EPA regulations.
Failure to properly identify and dispose of PCB-impacted construction and demolition debris can lead to significant financial and legal consequences. Improper disposal at non-permitted facilities has resulted in multi-million-dollar cleanup efforts and enforcement actions. In contrast, sites that proactively separate and handle PCB-impacted debris with proper disposal appropriately have seen substantial cost savings and minimized liability.
Safeguard Against Costly Remediation Pitfalls
By integrating advanced technologies like LiDAR and geophysical surveys, organizations can enhance the accuracy and efficiency of brownfield site assessments. As environmental challenges grow more complex, leveraging these innovative approaches helps stakeholders make informed, cost-effective decisions for sustainable site redevelopment.
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Kevin Ignaszak, PE
Senior Principal Engineer
Kevin is a Senior Principal Engineer with over 32 years of professional experience in environmental engineering, consulting, and design/build remediation. He brings extensive expertise in areas such as site investigation and remediation, brownfields redevelopment, PCB/TSCA management, environmental compliance, and project and program management. He has significant experience in PCB (polychlorinated biphenyl) characterization and remediation, having managed projects involving building materials, soil, and groundwater. Currently, Kevin is actively working on PCB site investigations and cleanups in Vermont, New Jersey, New York, and Alaska.
