Cascade's Quarterly Newsletter

Pathways Newsletter

Welcome to Pathways, your quarterly newsletter!

This issue offers a diverse look at innovative solutions for a range of environmental challenges. From the field, we share an update on a significant PFAS groundwater remediation project, detailing our use of ColloidalChem™ and Pathfinder™ to address contamination along a busy highway. We share a successful case study from Oakland, CA, showcasing how the use of Colloidal iZVI™ and microscale ZVI overcame complex subsurface conditions at a chlorinated solvent site. In addition, we explore the versatility and advantages of Dual Rotary Drilling for challenging drilling scenarios. Finally, we shine a spotlight on Permeable Reactive Barriers (PRBs), a powerful technology for long-term contaminant management.

PFAS Groundwater Remediation with ColloidalChem™ and Pathfinder™

After a fuel tanker overturned on a busy highway and firefighting foam (AFFF) was used to put out the resulting fire, PFAS contamination spread to nearby groundwater. Thousands of tanker spill incidents like this occur every year, and when elevated PFAS levels are detected in groundwater, it’s critical to implement immediate and cost-effective remediation, especially in cases like this where a pump and treatment system is not logistically practical.

To solve this challenge, the Cascade crew is implementing a turnkey solution utilizing ColloidalChem and Pathfinder technology to treat 4,750 sq feet of contaminated groundwater on opposing sides of the active highway. This innovative method promises to significantly reduce PFAS levels to meet stringent NJ and EPA drinking water standards.

Stay tuned for future updates as we progress on this groundbreaking project. If you have a PFAS-laden site and want to investigate your options, get in touch with our experts: Contact Us

Chlorinated Solvent Source and Permeable Reactive Barrier Groundwater Remediation

At a recent site in Oakland, CA, contaminated with chlorinated solvents (PCE, TCE, DCE, and VC), Cascade crews overcame complex subsurface conditions and delivered successful remediation outcomes.

The site presented several challenges, including the presence of silty clay layers within the subsurface, which can hinder the distribution of treatment agents. Traditional injection methods, such as those involving injection wells, may have struggled to achieve consistent contact with the contaminants in these challenging soil conditions.

To address these challenges, Cascade proposed an innovative approach utilizing Direct Push Technology (DPT) to inject a combination of Colloidal iZVI™ and microscale ZVI, along with bioaugmentation agents.

This approach offered several key advantages:

Enhanced Treatment Efficacy: DPT enabled precise placement of treatment agents within the target intervals, ensuring thorough contact with contaminants in the silty clay layers.
Reduced Risk of Well Screen Biofouling: Eliminating the need for injection wells minimized the risk of well screen biofouling, a common issue that can hinder treatment effectiveness.
Improved Treatment Longevity: The use of microscale and Collodial iZVI provided longer-lasting treatment zones, enhancing the long-term effectiveness of the remediation.
Cost-Effectiveness: Our approach ultimately resulted in lower overall costs compared to the original injection well proposal.

Download Case Study >>

Chlorinated Solvent Source and Permeable Reactive Barrier Groundwater Remediation

Ask the Expert

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What are the key advantages of using dual rotary drilling in environmental projects?

Answer: Dual rotary drilling offers several key advantages for environmental projects. This drilling technology is perfect for deep drilling projects because it allows for larger diameter boreholes – up to 24 inches across. Plus, it's great for projects where minimizing environmental impact is a top priority.

Since it reduces the need for drilling fluids, you can be confident you're not introducing any contaminants into the surrounding environment. And let's not forget its versatility, dual rotary rigs can seamlessly transition between different drilling methods, allowing you to adapt to any subsurface challenges you encounter. Want to learn more about when to consider Dual Rotary for your next project? Check out our blog post on, 5 Types of Projects Where You Should Consider Dual Rotary.

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Technology Spotlight: Permeable Reactive Barriers

Imagine in situ treatment with no above-ground structures.

A Permeable Reactive Barrier (PRB), also known as a permeable reactive treatment zone (PRTZ), is a technology designed for passive in situ treatment of contaminated groundwater. These barriers are used to intersect with the contaminant plume. When necessary, impermeable wings are installed to direct the flow of groundwater through the PRB.

The barriers are comprised of reactive materials that target dissolved phase contaminants as the groundwater flows through the barrier.

PRBs have replaced pump and treat remedies for contaminated groundwater with life cycle cost savings greater than 75%. Zero valent iron (ZVI) placed in the groundwater has been known to abiotically degrade a wide range of chlorinated compounds and energetics into non-toxic end products. Also, numerous heavy metals are immobilized and precipitated from the groundwater by the iron.

There are significant additional benefits to be gained by the Trenchless Method by Vertical Inclusion Propagation (VIP).

Construction of deep PRB systems with superior remediation efficacy over alternative remedies.
Proven technology with demonstrated effectiveness of placement of iron PRBs at both deep and shallow depths.
Installation of a continuous iron filing PRB with high permeability and porosity.
Minimal impact on the natural groundwater flow regimes.
Quality assurance and verification tests for confirmation of constructed PRB geometry, continuity, iron loading, coalescence and hydraulic characteristics.
Minimally invasive installation in congested workplaces in and around buildings and within areas with underground and overhead utilities and narrow right of ways.
Trenches construction - no excavation and minimal site disturbance.
Very safe with low-risk exposure to personnel and property.

Stop by to see us at the following events:

2025 NEC Airports Conference - Hershey, PA (03.03 - 03.05)
20th Annual EPAZ Conference - Tempe, AZ (03.03 - 03.04)
FAEP Conference - St. Petersburg, FL (3.12 - 3.14)
AEHS West - San Diego, CA (03.17 - 03.20)
NJ Site Remediation Conference 2025 - New Brunswick, NJ (03.26 - 03.27)
Clemson Hydrogeology Symposium - Clemson, SC (04.02 - 04.04)
DCHWS East 2025 - Philadelphia, PA (04.02 - 04.04)

PFAS in the News

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