May 2025 MSECA Meeting

Presented by Julio A. Zimbron, Ph.D., E-Flux

Natural Source-Zone Depletion (NSZD) is a term that has been applied to mass losses of non-aqueous contaminants (NAPL), mostly driven by microbial activity. The term was coined shortly after multiple methods were developed for field measurement of these mass lose rates associated with NSZD, known as NSZD rates. The measured field rates were consequential to the longevity of contaminated sites. It was not unusual that the NSZD rates were similar or even larger than active remedies. Since then, NSZD has found applications to the entire life cycle of a petroleum contaminated site, including source delineation, baseline remedy performance and remedy transition.

This presentation will describe a conceptual basis for NSZD processes, summary descriptions of the available methods to measure NSZD rates, examples of multiple applications of NSZD rate measurements, and a discussion of best practices to conduct NSZD rate measurements. Novel applications of NSZD concepts related to chlorinated contaminants will be discussed, and emerging trends in this industry will be described. Environmental professionals attending this talk will gain a broad view of this relatively new industry and also acquire specific knowledge useful to implement NSZD principles in their practice.

Julio A. Zimbron, Ph.D., E-Flux
Dr. Julio Zimbron is the founder and president of E-Flux, a company specialized on environmental measurements related to groundwater NAPL contamination sources.  After finishing a Ph.D. degree in chemical engineering from Colorado State University (2000), where he is now affiliated faculty, Dr. Zimbron’s experience includes environmental consulting, industrial research and development, and academic research. His work in the areas of natural source zone depletion (NSZD) and NAPL distribution and mitigation includes six patents, numerous technical papers, and participation in guidance documents. Dr. Zimbron presents multiple times a year at national and international conferences and workshops.

Presented by Bill Brab, PG, CPG, AST Environmental

A key to bedrock remediation is to not focus solely on highly transmissive zones. The smaller aperture fracture networks and overlying weathered bedrock habitually contain more residual contaminant mass than more transmissive features. Being able to access, isolate, and treat these zones is key to success at difficult fractured rock sites, and many sites require a combination of methods due to dissimilar properties between the less consolidated and consolidated units.The focus of this presentation will be to showcase recent improvements to techniques and approaches to access contaminant impacts in transition zones/saprolite/epikarst and consolidated lithologies for characterization in-situ remediation. This site-specific case study will illustrate the development of quantified, high-density CSMs using high-density, discrete groundwater sampling for quantitative lab.analysis, which provides for surgical and aggressive in-situ remediation techniques that install requisite in-situ treatment product precisely where it is needed.

Bill Brab, PG, CPG, AST Environmental
Bill Brab, PG, CPG is a Senior Remediation Geologist for AST Environmental, Inc. in Midway, Kentucky with 20 years of experience in environmental geology and site remediation. Bill is an expert in fractured bedrock characterization and is a recognized authority in Kentucky and Tennessee for his investigation and remediation of karst geology. Bill graduated from the University of Kentucky in 2001 with a Bachelor of Science in Geological and Earth Sciences and holds Professional Geologist licenses in Kentucky, Tennessee, and Alabama, and is a Certified Professional Geologist. He currently oversees and mentors junior geologists for advancing career development at AST, he is a Kentucky Governor appointed Executive Board Member for the Kentucky Board of Registration for Professional Geologists and serves as the Treasurer for the Kentucky Section of The American Institute of Professional Geologists.

Presented by Jim Depa, Jacob & Hefner Associates

Presented by Permveer Bains, Element Materials Technology

Although discussions around PFAS have long focused on AFFF‐contaminated sites—such as military bases and airports—current trends indicate that PFAS are now emerging in a broader array of industrial settings throughout Indiana. Many industry stakeholders remain uncertain about when and how PFAS risks will affect their operations. This presentation provides a timely context for PFAS in Indiana by:

• Examining the evolving landscape of PFAS contamination and identifying the types of sites that are likely to be affected in the coming years.
• Analyzing current regulations with comparisons to international frameworks, to forecast the regulatory trends that will shape how contaminated sites are managed.
• Reviewing the evolution of the PFAS methods and provide some context (with comparison to other “emerged” contaminants) to what we can expect in the future
• Outlining a straightforward, proactive toolkit that details practical steps—both immediate and long-term—that facilities can adopt to evaluate and control PFAS contamination before new regulatory mandates are enforced.

By clarifying the expanded scope of PFAS risks and offering actionable measures, this talk aims to equip industry professionals with the insights and tools needed to safeguard both their operations and the environment.

Permveer Bains, Element Materials Technology
Permveer is the Business Development Manager and PFAS Subject Matter Expert at Element bringing a full-spectrum perspective to the chemical industry – having sourced chemicals, sold those chemicals, and now leading the charge in testing for them.  A Professional Chemist with experience spanning pharmaceuticals, specialty chemicals, and analytical laboratories, Permveer specializes in helping industries navigate the evolving landscape of PFAS, regulatory compliance, and evolving analytical testing.

Presented by Joshua Richards, Pace Analytical

US EPA finalized EPA 1633 and 1621 in January 2024. This presentation will focus on what site investigation professionals need to know about the final methods. The discussion will highlight the evolution of the methods, coupled with a focus on several other lesser-known test methods that could be very powerful tools to the PFAS site investigation community. Method comparisons will be articulated, as well as case studies. Notably, the Department of Defense (DoD) is widely using these “alternative” tools to optimize large-scale site investigations across the country.

Joshua Richards, Pace Analytical
Joshua Richards is the Technical Sales Lead for Pace® Analytical’s Great Lakes region and leads a team of seven technical sales representatives covering four states, IN, KY, MI, and OH. Josh has been with Pace for over nine years and previously served as a program manager for Pace® Energy, Pace®’s former forensic testing location. Prior to coming to Pace, Josh spent nine years as an assessment/remediation geologist working for an international consulting firm in multiple offices worldwide. Joshua’s professional experience includes management of large-scale assessment/remediation projects and implementation of bioremediation, ISCO, ISTR, as well as complex hydrogeological investigations.

Mr. Richards received his BA in Geology from Indiana University-Purdue University at Indianapolis and his MS in Geology from the University of Florida.  He is a registered professional geologist in Florida and Indiana. Additionally, Mr. Richards is a Certified Hazardous Materials Manager.

Presented by Lauren Soos, TRS Group

TRS Group (TRS) completed its third and largest per- and polyfluoroalkyl substances (PFAS) soil remediation project in October 2024, using thermal conduction heating (TCH) with integral vapor extraction to treat a 2,000-cubic yard soil pile at Joint Base Elmendorf-Richardson (JBER) in Anchorage, Alaska. The project, funded by the Department of Defense’s (DOD) Environmental Security Technology Certification Program (ESTCP) in partnership with the Defense Innovation Unit (DIU), included detailed monitoring, sampling and analysis to track the fate of PFAS and remedial results.

This presentation will include: 

• Laboratory results showing removal efficiencies at various temperatures 
• Lessons learned from applying thermal desorption technologies at over 400⁰C
• Extraction of vapors and on-site treatment using cooling, condensation, and granular activated carbon
• Soil sampling and analytical results of PFAS concentrations before and after treatment
• Scaling the process for larger applications
• Strategies to reduce costs
• A sustainability perspective

Reducing the environmental impacts of PFAS will require the removal of source zones, protecting groundwater. TCH is a highly effective source zone treatment solution for PFAS-impacted soils.

Lauren Soos, TRS Group
Lauren Soos has over 20 years of experience in the environmental consulting and remediation industry, including managing complex thermal remediation projects across the country. She claims to have fallen in love with these technologies almost fifteen years ago and has enjoyed working collaboratively on implementation since. Mrs. Soos is an environmental engineer and directs sales and marketing at TRS Group. Mrs. Soos lives in New Hampshire with her husband, Seth, and daughters, Emma and Isla, where she enjoys backpacking, skiing, and her newest love, tennis.

Presented by Keith Gaskill, REGENESIS

The in-situ application of colloidal activated carbon (CAC) in a reactive barrier configuration is an established remediation strategy for reducing risk posed by PFAS contaminated groundwater.  Computer modelling provides a valuable design tool enabling contaminant flux, dynamic transfer between aquifer compartments, and competitive interactions between PFAS species for activated carbon sorption sites to be quantified.  Post application monitoring data allow the model to be further calibrated and refined.  Its use may then be extended through other project phases.  Deviation of field performance data from the modelled trajectory may be observed at certain points within a barrier.  This exposes zones that may require engineering attention.  Pre-installation design modelling and post-installation model-supported adjustment is analogous to design and commissioning of mechanical systems such as hydraulic containment installations.  This presentation provides an illustration of the model-supported commissioning process drawing from a case study of a midwestern PFAS site.

Keith Gaskill, REGENESIS
Mr. Gaskill has worked as a scientist for over 24 years in the environmental industry. He earned a Bachelor’s degree in geology from Ball State University and a Master’s degree in hydrogeology and geochemistry from Northern Illinois University. He has performed project tasks such as site investigations for a variety of property management and property sales issues; UST/AST investigation and removal; petroleum pipeline and bulk storage response and remediation, site investigation/remediation at drycleaner facilities across the UnitedStates; computer modeling of groundwater systems and geochemical fate and transport; hydrological and hydrogeological assessments, mechanical remediation system conceptual design and implementation; pilot testing and remediation feasibility studies; expert witness services; extensive site investigation and delineation studies using traditional and TRIAD methodology; various types of hydrogeologic testing such as slug testing and pump testing; operation and data management of Membrane Interface Probe (MIP) and mobile lab technologies; management of multiple sites for major oil companies, drycleaners, and miscellaneous industry. Mr. Gaskill also focuses on high data density and high-resolution data analysis and conceptual site model production for the purpose of remedial design. Mr. Gaskill has performed small to large scale tracer studies and remediation activities in a variety of geologic settings including porous and fractured bedrock. Mr. Gaskill provides innovative and effective remediation designs for his clients and has completed remedial designs for more than 50 PFAS projects.

Presented by Ryan Moore, REGENESIS

To minimize the risks posed by PFAS, it is essential to reduce potential exposure by decreasing PFAS migrating from contaminated areas into groundwater. Activated carbon is a promising and widely available adsorbent that effectively immobilizes PFAS, significantly reducing the mass flux of these contaminants. In this study, the activated carbon has been milled to a size of 1-2 microns to enhance its ability to adsorb PFAS quickly by increasing its external surface area. We will test the submicron-sized activated carbon, referred to as colloidal activated carbon (CAC), alongside powdered activated carbon (PAC) to effectively reduce PFAS mass flux from soil contaminated by a former fire pit. This approach aims to provide a highly efficient and economical remediation solution. A field study was to validate the PFAS leaching reduction using a PAC and CAC combination. The treatment involves mixing highly PFAS-impacted soil with PAC and CAC. Due to the small particle sizes of PAC and CAC, carbon distributed well throughout the treatment area. Soil porewater samples were collected through lysimeters at 6- and 12-months post-treatment. PFAS concentrations in the soil porewater represent PFAS leaching from the source zone to groundwater. Our results show over 99% PFAS reduction in porewater samples after mixing the PFAS-impacted soil with the carbon-based remediation approach, compared to the porewater samples collected from adjacent untreated areas. Amendment performance was also assessed by monitoring PFAS concentration in groundwater and PFAS leachability via the synthetic precipitation leaching procedure (SPLP). The data highlight the importance of addressing the capillary fringe within source zones and homogeneous amendment distribution for soil stabilization.

We will present our implementation techniques to mix PAC and CAC within the test treatment area. Additionally, we will discuss the concentrations of PFAS in porewater, groundwater and leachability samples, as well as the lessons we learned to enhance the PFAS leaching reduction. Overall, our results highlight the significance of the carbon-based in situ treatment in halting

Ryan Moore, REGENESIS
Ryan Moore has more than 22 years of experience as an environmental project manager and laboratory account executive relating to multimedia contamination sites throughout the U.S. His experience focused on in situ groundwater and soil treatment, site investigations, corrective action evaluations, operation & maintenance of remediation systems, large soil removal remedial projects, vapor intrusion assessments, and environmental laboratory operations such as QA/QC evaluations, data interpretations, and business development. He has also presented at multiple conferences on in-situ remediation including events hosted by Battelle, AIPG, and other environmental associations. Ryan holds a B.S. of Environmental Studies from Manchester University, North Manchester, IN.