Remediating TCE‐contaminated groundwater in low‐permeability media using hydraulic fracturing to emplace zero‐valent iron/organic carbon amendment

Swift, Dana L.; Rothermel, Joe S.; Peterson, Lance N.; Orr, Brennon R.; Bures, Gordon H.; Weidhaas, Jennifer

doi:10.1002/rem.21310

Cited by 11 publications

(7 citation statements)

References 25 publications

(25 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Over time, the guar gel degrades, leaving sand to support the integrity of the facture while allowing for fluids to more easily penetrate through the newly created fracture network (ITRC 2005). Amendments can be incorporated into the fracturing fluid to support in situ remedial technologies (e.g., biodegradation, electrokinetics, vitrification, air sparging) (Suthersan 1999; Swift et al 2012) or can be injected after fracturing into the newly created fracture network (e.g., emulsified zero valent iron [EZVI]) (Quinn et al 2004).…”

Section: Subsurface Access Methodsmentioning

confidence: 99%

Methods for Delivery and Distribution of Amendments for Subsurface Remediation: A Critical Review

Muller¹,

Johnson²,

Bagwell³

et al. 2020

Groundwater Monitoring Rem

View full text Add to dashboard Cite

The ability to reliably deliver and widely distribute remedial amendments through the subsurface environment is of paramount importance to achieve cleanup objectives for contaminated sediments and groundwater for protection of sensitive environmental habitats and natural resources. A wide range of amendments, delivery techniques, and subsurface access methods are available. However, the applicability of these approaches is dependent on a multitude of site‐specific factors. In this review, an overview of amendments and access/distribution methods is provided, along with discussion of the maturity level, advantages, and limitations that relate to the potential effectiveness of each approach in the context of site‐specific factors. Each amendment and delivery approach are further evaluated for applicability to the following subsurface target zones: saturated, unsaturated, and perched water, with specific focus on high and low permeability regions in each zone. The review highlights a critical need for field‐tested approaches targeting unsaturated and perched water zones, as well as low‐permeability regions within all subsurface regions. The intent of this review is to provide critical information and insight into how amendments can be delivered, emplaced, and/or distributed effectively in the subsurface environment to effectively manage subsurface contamination.

show abstract

Section: Subsurface Access Methodsmentioning

confidence: 99%

Methods for Delivery and Distribution of Amendments for Subsurface Remediation: A Critical Review

Muller¹,

Johnson²,

Bagwell³

et al. 2020

Groundwater Monitoring Rem

View full text Add to dashboard Cite

show abstract

“…The characteristics of emplaced fractures and the distribution of the fractures relative to the contaminant distribution are key features of this approach (Swift et al 2012). For example, Chambon et al (2010) concluded that 0.0025‐cm thick fractures spaced 1 m apart would not be sufficient to ensure site remediation in clayey till through ERD in a reasonable time frame, while Scheutz et al (2010) suggest that 1‐ to 2‐cm thick fractures spaced 0.1 to 0.4 m apart may be sufficient to ensure remediation through ERD in a reasonable time frame.…”

Section: Literature Reviewmentioning

confidence: 99%

“…A variety of pilot‐ or full‐scale fracturing tests have been reported in the literature, and these works can loosely be placed into one of two categories: investigations of fracturing techniques and resulting fracture characteristics (Murdoch et al 2006; Christiansen et al 2008, 2010, 2012; Sorenson 2019), and tests of contaminant treatment with fracturing techniques. The latter category can be divided based on remediation strategy: fractures to promote abiotic degradation through oxidation/reduction reactions (Siegrist et al 1999; Swift et al 2012; Sorenson 2019), fractures to promote biodegradation (Scheutz et al 2010; Swift et al. 2012; Horst et al 2019; Sorenson 2019), fractures for steam flushing (Nilsson et al 2011), or fractures to promote EK treatment (Murdoch and Chen 1997; Roulier et al 2000).…”

Section: Literature Reviewmentioning

confidence: 99%

“…A variety of pilot-or full-scale fracturing tests have been reported in the literature, and these works can loosely be placed into one of two categories: investigations of fracturing techniques and resulting fracture characteristics (Murdoch et al 2006;Christiansen et al 2008Christiansen et al , 2010Christiansen et al , 2012, and tests of contaminant treatment with fracturing techniques. The latter category can be divided based on remediation strategy: fractures to promote abiotic degradation through oxidation/reduction reactions (Siegrist et al 1999;Swift et al 2012;, fractures to promote biodegradation (Scheutz et al 2010;Swift et al 2012;Horst et al 2019;, fractures for steam flushing (Nilsson et al 2011), or fractures to promote EK treatment (Murdoch and Chen 1997;Roulier et al Siegrist et al (1999) conducted a comparative study in which hydraulic fracturing was used to emplace amendment into a TCE contaminated clay and silt formation. The tests were conducted in the vadose zone, but with high water saturation (90%) and nonetheless provide useful information for LPZ treatment in the saturated zone.…”

Section: Fracturingmentioning

confidence: 99%

See 1 more Smart Citation

Strategies for Managing Risk due to Back Diffusion

Brooks¹,

Yarney²,

Huang³

2021

Groundwater Monitoring Rem

View full text Add to dashboard Cite

Back diffusion of contaminants from secondary sources may hamper site remediation if it is not properly addressed in the remedial design. A review of all reported technologies and strategies that have been or could be applied to address plume persistence due to back diffusion as published in the peer‐reviewed literature is provided. We classify these into four major categories. The first category consists of those approaches that do not include active measures to specifically address contamination in the low permeable zones (LPZs) and can therefore be considered passive LPZ management approaches. A disadvantage of these approaches is the long duration that may be required to meet acceptable endpoints; however, this allows degradation to potentially play a significant part even at modest rates. The remaining three categories all use approaches to specifically address contaminants in the LPZ. The second category consists of strategies that promote contaminant destruction through the forward diffusion of amendments into the LPZ. A variety of laboratory tests indicate concentration or flux reductions range from no improvement, to reductions as high as four orders‐of‐magnitude depending on the evaluation metric. The third category consists of strategies that alter physical characteristics of the secondary source, and includes viscosity modification, fracturing, and soil mixing. Each of these offer unique advantages and are often used to deliver one or more amendments for contaminant treatment. The final category consists of thermal and electrokinetic remediation, both less susceptible to permeability contrast limitations. However, they are not routinely used for secondary‐source treatment.

show abstract

“…Excavation or soil mixing with remedial amendments (e.g., zero‐valent iron [ZVI] and clay mixing) can be very effective; however, these techniques are invasive, are typically limited to shallow depths, and require relatively lengthy field operations (Horst et al, 2019; Olson et al, 2017). Coupling traditional direct‐push injection techniques with hydraulic or pneumatic fracturing of low‐k media can improve distribution of remedial amendments; however, the unpredictability and inconsistency of induced fractures can hinder treatment effectiveness (Suthersan et al, 2011; Swift et al, 2012). There are other promising technologies for enhanced delivery of remedial amendments in low‐k media, but many remain in early stages of development and require further optimization at the field scale.…”

Section: Introductionmentioning

confidence: 99%

A novel application of a geotechnical soil stabilization technology for improved delivery of remedial amendments

Richardson

Kolz²,

Hart

et al. 2022

Remediation Journal

View full text Add to dashboard Cite

Accelerating the remediation of contaminants that have diffused into low‐permeability (low‐k) geologic units such as silts and clays is a key need for the groundwater remediation industry. Injection‐based remedial technologies are often ineffective because the injected amendments are more likely to influence transmissive media (sands and sandy silts) and generally do not penetrate low‐k units. While some emerging technologies are now being tested, they are often expensive or have other technical limitations (e.g., installation depth and rate of amendment emplacement). To address the problem of treating contaminants in low‐k media, a geotechnical technology called the “Grout Bomber” (Keller North America) was repurposed for an environmental application to emplace ~800 vertical “reaction columns” containing zero valent iron (ZVI), sand, and neat vegetable oil for the treatment of chlorinated volatile organic compounds (CVOCs) in lean clays and sandy clays. The reaction columns were closely‐spaced (2–3 ft apart) to greatly accelerate the back diffusion of CVOCs from the low‐k media to the reaction columns where contact with ZVI and vegetable oil promotes abiotic and biotic reductive dechlorination of CVOCs, respectively. Overall, 35 tons of ZVI were emplaced into the 5200 cubic yard (yd3) (~4000 m3) source zone during the project. Key benefits of this technology include rapid installation (average of 107 reaction columns per day), ease of remediation amendment mixing, consistent amendment dosing, and relatively low unit installation costs ($71 per cubic yard of treatment zone). It should be emphasized that this application of the Grout Bomber relies on diffusion of contaminants into the reaction columns from the surrounding low‐k media—a process that occurs slowly over years to decades. A planning‐level model showed that installation of closely spaced vertical reaction columns in a TCE‐laden clay unit reduced the time to achieve maximum contaminant levels from greater than 500 years to approximately 26 years. Groundwater monitoring confirmed the establishment of a concentration gradient between the reaction columns which promotes diffusion of CVOCs toward the reaction columns. The presence of dissolved acetylene and gaseous “higher coupling” products (>C3) provide further evidence of ongoing abiotic reductive dechlorination within the reaction columns.

show abstract

Remediating TCE‐contaminated groundwater in low‐permeability media using hydraulic fracturing to emplace zero‐valent iron/organic carbon amendment

Cited by 11 publications

References 25 publications

Methods for Delivery and Distribution of Amendments for Subsurface Remediation: A Critical Review

Methods for Delivery and Distribution of Amendments for Subsurface Remediation: A Critical Review

Strategies for Managing Risk due to Back Diffusion

A novel application of a geotechnical soil stabilization technology for improved delivery of remedial amendments

Contact Info

Product

Resources

About