Part 2: Using In Situ Soil Mixing for PRBs or Barrier Walls

Innovative Environmental Construction Technologies Webinar Series

When remediation budgets are tight and regulatory pressure is high, choosing the right containment approach can make the difference between staying on schedule and facing costly delays. In this session, our technical specialists will share practical insights on using soil mixing for permeable reactive barriers (PRBs) and hydraulic barrier walls, especially in complex conditions like high groundwater flow or unstable soils. We’ll discuss where soil mixing can reduce costs and simplify execution, and where it may not be the right fit.

Don’t miss this opportunity to learn directly from experts who have implemented these systems on real sites with budget, compliance, and timeline constraints.

What you’ll gain from attending:

  • Cost-Saving Strategies Under Regulatory Pressure: Understand how in situ mixing helps control disposal, backfill, and transportation costs while supporting compliance with stringent cleanup requirements.
  • When Soil Mixing Makes Sense and When It Doesn’t: Learn how to evaluate site conditions, contaminant profiles, and performance goals to determine applicability.
  • Risk and Schedule Management Guidance: Hear best practices for mitigating construction risks, minimizing site disturbance, and accelerating delivery compared to excavation or slurry wall approaches.
  • Real-World Case Examples: See how soil mixing has been used to install PRBs and barrier walls on challenging sites and what lessons were learned along the way.

Whether you’re evaluating alternatives or looking to reduce cost and performance uncertainty, you’ll leave with practical guidance for incorporating in situ soil mixing into your project designs.

About the Presenters

Paul Lear, Ph.D

Senior Technical Director, Civil & Environmental Construction

Dr. Paul Lear, a leading authority in stabilization/solidification (S/S) technology, brings over 30 years of experience in full-scale remediation projects to Cascade. As a key technical expert in In Situ Stabilization (ISS), Dr. Lear has pioneered numerous groundbreaking advancements in the field. Dr. Lear's expertise extends internationally, with notable achievements such as the first S/S of organic wastes in Australia and the first large-scale S/S treatment in Canada.

Deborah Shaffer (Schnell), P.E.

Director of Project Management, Civil & Environmental Construction

Deborah Shaffer (Schnell) is the Director of Project Management at Cascade. She is a leading national expert on permeable reactive barriers (PRBs), hydraulic and pneumatic fracturing, and in situ technologies such as in situ chemical oxidation (ISCO) and in situ chemical reduction (ISCR), with a focus on amendment distribution. Deborah works with clients to select the best remedial technology for their sites, based on data presented in their conceptual site model (CSM), project timelines, and budget.

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