by Joel Kane, Sr Associate, Fleming Lee Shue

Advancements in in-situ remediation technologies have enabled practitioners to aggressively target even the most persistent environmental contaminants. However, it is critical for environmental professionals to recognize that these technologies may unintentionally alter subsurface geochemistry and mobilize or concentrate non-target compounds. This phenomenon—referred to as Technologically Enhanced Contamination—can present unforeseen challenges during long-term monitoring, site closure, and waste management.

TENORM

One of the clearest examples of this phenomenon involves the concentration of Naturally Occurring Radioactive Materials (NORM)—such as isotopes of uranium, thorium, and radium—which are present in trace amounts in soil and groundwater. When groundwater is extracted and treated in large volumes, trace levels of NORM can accumulate in scale deposits, filter media, and sludge within treatment systems. Over time, these accumulations may exceed background levels and surpass regulatory thresholds, transitioning into Technologically Enhanced Naturally Occurring Radioactive Material (TENORM)¹.

This process is well-documented in oil and gas operations, where radium-rich scale forms during initial crude separation. Similarly, coal—a common carrier of radioactive isotopes—can produce TENORM when combusted, with radionuclides concentrating in the resulting coal ash. When such ash is later used as fill material, as historically was the case in much of New York City, a remedial system (such as a pump-and-treat well or recovery trench) can unintentionally accumulate TENORM within filters and piping.² 

Although certainly not a concern at every site, properties with specific risk factors — such as historic coal ash fill or long-term groundwater extraction systems — may benefit from evaluation of potential TENORM accumulation within treatment infrastructure.  Monitoring of scale, filters, and sediments, and proper waste characterization prior to disposal, may be important steps for mitigating radiological health and safety risks. 

ERH and Secondary Contaminant Mobilization

The combined use of Electric Resistance Heating (ERH) and Soil Vapor Extraction (SVE) can significantly enhance the removal of volatile and semi-volatile organic compounds. ERH increases subsurface temperatures, volatilizing contaminants and improving mass transfer to the vapor phase, where they are captured by SVE systems.

However, superheating the subsurface can also inadvertently increase the mobility of otherwise immobile contaminants—such as Polychlorinated Biphenyls (PCBs). Though PCBs have low volatility under ambient conditions, elevated temperatures enhance their partitioning to the vapor phase.³  When combined with the strong advective forces of an SVE system, low-level PCB concentrations can migrate toward extraction points, and potentially concentrate in knock-out drums, vapor treatment vessels, and even within localized areas of the subsurface if not fully extracted by the SVE.

Several studies and post-operation evaluations have identified unexpectedly high PCB concentrations in vapor-phase effluent and condensate, requiring specialized waste handling and disposal.⁴  While ERH remains a powerful tool, practitioners must anticipate the possibility of mobilizing compounds not originally targeted in the remedial design.

ISCO and Metal Mobilization

In Situ Chemical Oxidation (ISCO) is another widely used remedial technology, wherein strong oxidants—such as sodium persulfate, permanganate—are injected into the subsurface to destroy organic contaminants.

However, these oxidants can often significantly alter the geochemical balance of the aquifer. They may lower pH, increase redox potential, and raise ionic strength—conditions that favor the dissolution of naturally occurring metals previously bound to soil minerals. Following ISCO treatment, it is not uncommon to observe elevated concentrations of iron, manganese, arsenic, and lead within the groundwater monitoring programs.⁵ 

Though these metals are not typically the focus of remediation, their mobilization can complicate site closure or regulatory compliance, particularly if they were previously below detection limits. For sites considering ISCO, baseline groundwater chemistry should be evaluated in advance, and post-treatment monitoring should include metals to assess for geochemically driven mobilization.

ERH-Induced Geochemical Shifts and Metals

In addition to contaminant volatilization, ERH can cause broader geochemical shifts within the local affected aquifer. When highly chlorinated solvents—such as PCE or TCE—are thermally degraded, the reaction often generates free chloride ions, which can acidify the groundwater and increase its ionic strength.⁶

This shift enhances the solubility of subsurface metals, which may then appear in monitoring data as elevated concentrations of iron, manganese, arsenic, or lead. While often transient, these metals spikes can delay regulatory closure or complicate long-term monitoring, especially when concentrations exceed site-specific cleanup criteria.

As with ISCO, pre-treatment geochemical profiling and careful interpretation of post-treatment data are critical for managing unintended consequences.

Implications for Remedial Design and Site Management Monitoring

Modern remedial technologies offer powerful tools to achieve cleanup goals, but it is important to be aware that they may also trigger secondary effects that are not immediately apparent during remedy design. Subsurface heating, oxidation, and even pump & treat can all change the behavior of metals, radionuclides, and semi-volatile organics in ways that can influence both short and long-term outcomes.

To help best anticipate and manage Technologically Enhanced Contamination, environmental professionals may opt to:

• Conduct thorough baseline investigations of groundwater chemistry and geologic conditions
• Develop a robust conceptual site model that considers geochemical responses
• Monitor non-target compounds throughout and after system operation
• Coordinate with regulators early to plan for temporary and/or unexpected byproducts or secondary contaminant mobilization/spikes.

Understanding these site-specific interactions is critical for managing costs, ensuring regulatory compliance, and achieving sustainable site closure.

1. U.S. EPA (2022). TENORM in Oil and Gas Production. https://www.epa.gov/radiation/tenorm-oil-and-gas-production-wastes
2. NYC Department of Environmental Protection. Historical Fill and Ash Use in NYC.
3. Johnson, G. et al. (2009). PCB Behavior in Subsurface Thermal Remediation. Environmental Science & Technology.
4. Heron, G., Van Zutphen, M., & Carroll, S. (2009). “Design and performance of an in situ thermal remediation at a former manufacturing facility.” Remediation Journal, 19(3), 5–21. Rogers, R.D., et al. (1999). “Application of electric resistance heating to PCB-contaminated soils.” Journal of Hazardous Materials, 68(3), 235–256.
5. Interstate Technology & Regulatory Council (2005). In Situ Chemical Oxidation Guidance Document.
6. Lee, T.Y., et al. (2015). Impact of Thermal Remediation on Groundwater Geochemistry. Environmental Science: Processes & Impacts.

The Author:

Joel Kane is a Senior Associate at Fleming Lee Shue, where he oversees the firm’s technical operations and manages a diverse portfolio of remediation projects across the greater New York Metropolitan Area. He specializes in complex remediation sites and his experience spans both the public and private sectors. Joel works closely with developers, agencies, real estate firms, and legal teams to navigate environmental regulations across local, state, and federal programs—including NEPA, CERCLA, the Brownfield Cleanup Program, E-Designations, petroleum spills, and CEQR/SEQR.

By Michelle Onofrio, National PFAS Technical Manager, ALS USA Environmental

Per- and polyfluoroalkyl substances (PFAS) are hazardous compounds that have been used heavily in manufacturing since the 1950s. While their usefulness is derived from their chemical structure, the strong carbon-fluorine (C-F) bonds present in these compounds render them resistant to degradation. PFAS are well-known to be persistent and ubiquitous in the environment and have been found in environmental samples around the globe, but the distribution and concentrations of these contaminants vary across the USA.

The wide array of brownfield redevelopment sites presents a multitude of potential contamination sources. When considering the potential for high levels of PFAS contamination, it is important to consider the history of land use at a particular site and the site’s proximity to certain areas. In this article, we discuss how to consider historical land use to anticipate whether PFAS are likely to be contaminants of concern.

Manufacturing and chemical sites

Obvious sources of PFAS contamination include manufacturing facilities that developed PFAS or used PFAS heavily in manufacturing processes. Industrial use of PFAS is highly concentrated in the Northeastern USA, especially along the I-95 corridor.

Regions with historical manufacturing of chemicals, paints and coatings, urethane and foam, textiles and carpeting, paper and food packaging, plastics and resins, metal plating, and other industrial processes are likely to contain high levels of PFAS in the surrounding environment.

Manufacturing processes that typically do not involve PFAS are less likely to have PFAS contamination as a major concern. These include bricks and ceramics manufacturing, lumber milling and woodworking, blacksmithing and metal forging, and glassmaking.

The age of a manufacturing facility can also be an indicator of whether PFAS contamination is present; areas that were only used for manufacturing before the 1950s are unlikely to pose a risk for PFAS contamination.

Airports and firefighting training areas

Aqueous film-forming foam (AFFF) is used to combat specific fires, including aviation fires. AFFF typically contains very high concentrations of PFAS, so airports and firefighting training locations may be source locations for significant PFAS contamination. Until recently, AFFF was typically not treated as hazardous waste after use.

Instead, it was generally washed away with water, introducing high concentrations of PFAS to soil, groundwater or surface water in the surrounding environment. AFFF storage tanks and systems may still contain PFAS, even if the systems are no longer in use.

Municipal and industrial waste landfills

Before health risks associated with PFAS were known, PFAS were used in many common household items including nonstick cookware, food packaging materials, personal care products, cleaning products, electronics, and clothing and carpeting manufactured to be water-resistant, stain-resistant and/or fire-resistant.

Once discarded, these items introduce PFAS into municipal landfills. Landfills that have accepted industrial waste from PFAS-heavy manufacturing facilities are also likely to contain increased concentrations of PFAS.

Wastewater treatment plants and land-applied sewage sludge and biosolids

Sewage sludge refers to untreated residual material produced by wastewater treatment plants, while biosolids indicate a sludge that has received some level of treatment. Sewage sludge and biosolids have been used for land applications since the early 1900s. The standards for wastewater treatment established by the Clean Water Act in 1972 resulted in an increase in the generation of biosolids, and subsequently land application throughout the country.

Sewage sludge treatment does not specifically target PFAS, so even treated biosolids can contain these contaminants. Wastewater treatment plant discharge and land-applied biosolids, especially if produced near highly contaminated areas, are likely sources of PFAS contamination in the environment.

Analytical considerations for highly contaminated sites

Samples originating from the areas described may contain PFAS at concentrations of orders of magnitude higher than other typical samples. When considering a laboratory partner for analysis of these types of samples, it is beneficial to ensure the laboratory employs mitigation strategies to overcome the challenges of processing high-concentration PFAS samples.

Communication throughout the course of your site testing and analysis project is crucial; it is encouraged to discuss site history with your project manager, and you should expect timely updates regarding any challenges that may arise.

High-quality data and rapid turnaround times are achievable with these types of projects, especially when using a laboratory experienced in analyzing highly contaminated samples for PFAS.

The Author:

Michelle Onofrio is the National PFAS Technical Manager for ALS USA Environmental. Michelle provides technical support on workflow optimization and new method development, prioritizing quality and consistent, reliable service. Michelle works closely with the company's PFAS laboratories throughout the country in New York, New Jersey, Pennsylvania, Michigan, Texas, and Washington.

By Bill Allgeier, Laboratory Manager, ALS USA Environmental

When it comes to monitoring Volatile Organic Compounds (VOCs) at brownfield sites, especially those in remote or power-limited locations, passive air sampling offers an accessible, reliable option. Unlike active sampling—which requires power sources and calibrated pumps—passive techniques rely on diffusion to collect samples over time. 

These low-maintenance approaches are growing in popularity across site remediation, health and safety, and fenceline monitoring projects. This article covers the different passive VOC sampling tools available, their strengths, and how to choose the right one for your site.

Cost Effective, Field-Friendly

Passive air sampling collects airborne contaminants without pumps or powered devices. Instead, compounds are captured as they naturally diffuse through the air and into the sampling media. It’s a cost-effective and field-friendly method, ideal for long-duration monitoring or projects where access is limited. Common applications include indoor air testing, ambient outdoor air, personal exposure monitoring, and soil vapor investigations.

Passive VOC Sampling Tools

There are four key passive sampling options for VOCs. Each tool fits different field conditions, project goals, and regulatory contexts.

• Silonite Canisters are ideal for “whole air” sampling. The canisters are filled over 24 hours using a flow regulator – they require no pump and allow for analysis of 60+ VOCs. Additional methods like reduced sulfur compounds and fixed gases can be analyzed from the same canister, removing the need to deploy multiple sampling techniques. They're highly versatile and suitable for indoor, outdoor, and soil vapor applications.
• Passive TD Tubes are used for long-term sampling (up to 14 days, depending on the compound), especially for low-level VOC monitoring. They're small, rugged, and comply with EPA Method 325. Great for fenceline, LDAR, and indoor use. However, typically they have a limited number of analytes that can be reported. 
• VOC Badges are the go-to option for personal exposure monitoring. Workers wear the badge for up to 8 hours to assess individual VOC exposure levels. These are compliant with occupational health standards.
• Radiello Samplers are flexible samplers with a 7-day deployment window, ideal for industrial or mining sites. They measure up to 31 VOCs and can also support non-VOC testing (e.g., formaldehyde, NO2).

Need to ship your samples fast? Canisters and TD tubes don’t require refrigeration and ship easily with commercial couriers.

Choosing the Right Tool for the Job

Selecting the best method depends on your project objectives, site conditions, and regulatory requirements. Consider:

• •Sampling duration – Canisters (any duration up to 7 days), TD tubes (up to 14 days, depending on the compound), badges (8 hours), and Radiello (7 days).
• Target VOCs – Do you need a wide panel (e.g., over 60 compounds)? Go with canisters. Need a focused list? Badges or TD tubes may suffice.
• Sampling environment – For personal exposure, use VOC badges. For soil vapor, ambient air or industrial zones, canisters or TD tubes work better.
• Accreditation needs – For example, ALS provides NELAP & AIHA accreditation for methods using canisters and TD tubes, ensuring data meets defensibility standards.

Why Passive Sampling Works Well for Brownfield Sites

Passive sampling is often the best fit for brownfield redevelopment projects because it’s simple, scalable, and doesn’t require power or bulky equipment. It can support key project stages, including baseline air quality assessments, post-remediation verification, and long-term monitoring. And since these methods are non-intrusive, they’re ideal in community-sensitive areas.

Whether you’re assessing indoor air, monitoring an industrial fenceline, or verifying cleanup at a brownfield site, passive VOC sampling is a proven and practical approach that ensures your sampling campaign is efficient, accurate, and compliant.

The Author:

Bill Allgeier is Laboratory Manager of the ALS USA Environmental full-service laboratory in Rochester, NY.  Bill has been with the ALS environmental team for 26 years as an Analyst, Operations Manager and Lab Manager, and oversees a 24,000 sq ft. facility where the team processes over 290,000 air, soil, water, drinking water and waste sample tests annually.   Email: bill.allgeier@alsgobal.com

by Christopher D. Valligny, LSRP, Montrose Environmental

Embreeville Park in West Bradford Township, Pennsylvania, is a testament to what’s possible when environmental remediation, historical stewardship, and community planning converge. Once home to a psychiatric hospital complex dating back to the 19th century—and later, a brownfield marked by contamination and deteriorating infrastructure—the 200-acre property has been reimagined into preserved open space through a collaborative effort grounded in sustainable redevelopment.

In 2019, facing a proposal for more than 1,100 residential units, residents rallied to chart a new course for the site. With community backing, the Township acquired the property for $22.5 million, halting the proposed high-density development and committing to the site's long-term ecological and historical value.

Tackling Environmental Liability with Strategic Funding and Compliance

Redeveloping a property of this scale—and complexity—demanded not just public support but also a robust financial and technical roadmap. Montrose’s brownfield experts helped secure a $1.5 million grant through the Land and Water Conservation Fund and assembled a layered funding portfolio with state and local partners. That financing enabled critical assessment, remediation, and early redevelopment work.

Milestones included:

1. Phase I & II ESAs to characterize environmental conditions and target contamination.
2. Act 2 Program compliance, resulting in a Release of Liability and setting the legal foundation for future recreational reuse.
3. Hazardous and universal waste removal, paired with geotechnical efforts that allowed on-site demolition debris to be safely reused for land stabilization.

Historic Preservation and Community Cohesion

The park’s transformation wasn’t limited to environmental cleanup. Guided by archaeologists, the project protected Native American cultural resources—preserving local heritage while restoring the land’s public utility. As of 2024, 185 acres have been designated for passive recreation and conservation. Planned improvements include walking trails, ball fields, and interpretive signage to showcase both natural and cultural history.

Lessons for the Northeast Brownfield Community

Embreeville Park offers replicable insights for BCONE members and other Northeast stakeholders:

1. Community-Driven Outcomes: The pivot away from dense redevelopment exemplifies how public input can shift brownfield narratives toward long-term, non-commercial value.
2. Creative Reuse: On-site material recovery for stabilization cut costs and reduced waste—an essential approach for municipalities with limited redevelopment budgets.
3. Integrated Partnerships: Success hinged on tight collaboration between municipal leaders, environmental consultants, legal experts, and funding agencies.

The Author:

Christopher D. Valligny, LSRP, Senior Scientist II, Montrose Environmental Chris is a Senior Scientist with over 15 years of experience in environmental consulting, ecological research, and policy implementation. Licensed as a NJDEP Licensed Site Remediation Professional and UST Closure/Subsurface Evaluator, he also holds OSHA 40-Hour HAZWOPER certification. Chris manages complex brownfield investigation and remediation projects—including Phase I/II Environmental Site Assessments—throughout New Jersey, Pennsylvania, and Delaware. His interdisciplinary approach supports a diverse client base of insurers, municipalities, developers, nonprofits, and legal teams.

by Abraham Cullom, PhD, Pace® Director of Water Safety & Management

The Author:

Abraham Cullom, Ph.D., Director of Water Safety and Management, Pace® Building Sciences  Dr. Cullom is the Director of Water Safety and Management at Pace®. He holds a B.S. from the University of Pittsburgh and a Ph.D. from Virginia Tech in Civil and Environmental Engineering, where he published multiple peer-reviewed papers demonstrating the impact of in-building plumbing environments on important opportunistic pathogens, antibiotic resistance, and microbial ecology. A cross-disciplinary expert, Dr. Cullom translates insights from engineering, microbiology, and chemistry into practical solutions to mitigate disease risks in water systems and help end Legionnaire’s disease.

By Matthew J. Gozdor, Quantitative Hydrogeologist/Senior Technical Specialist at GZA GeoEnvironmental, Inc.

With artificial intelligence (AI), scientists and engineers are faced with a familiar question: The tools are impressive on their own, but how do we use them to provide effective, reproducible results? Our recent work for a client to develop a groundwater model that was as accurate as traditional modeling but with fewer data points and lower cost helps illustrate the way forward.

For this project, we focused on machine learning (ML), which is a subset of AI. ML uses algorithms and statistical models to analyze data for patterns, draw inferences from those patterns, and learn from the patterns without being issued explicit instructions. In this instance, we needed to demonstrate to regulators that impacted groundwater was discharging to a nearby stream and not flowing underneath the stream.  

Traditional modeling to meet our objective required obtaining a significant amount of information through complex field work and gathering historical information, LIDAR data, geological data, etc. The information needs for our ML model were significantly less and limited to weather information from a nearby weather station, river elevation data, and groundwater levels. Our AI-assisted model used Python, a common programming language popular in the ML community, and an open source “package” named Pastas developed for groundwater scientists and engineers to analyze hydrogeological time series. Pastas uses a transfer function noise model to show how the groundwater system will respond to a  stressor (e.g., precipitation) while also incorporating random noise on the output to better reflect the complexity of a hydrogeological system. 

To test the model, we used it to predict future groundwater elevations which were compared to actual measured values over time. Using the Normalized Root Mean Square Error (NRMSE), which compares the predicted values against the observed values while normalizing them by the standard deviation of the observed data, we found that our ML model’s values came within 2% of real-world observations.

Our approach has the potential to be used in a wide range of groundwater scenarios, from estimating snowmelt effects to controlling groundwater in tunneling operations. Core to going forward, however, will be ensuring that the model reflects the real-world data, and that the data reflects the risks: In other words, trust, but verify. 

Scientists and clients are understandably concerned about how to use these tools and where they fit into our work. By developing ML models that can be checked against real-world results, and carefully choosing what data a model is built on, clients and contractors alike can make better-informed decisions, while saving time and money.

The Author:

Matthew J. Gozdor is a Quantitative Hydrogeologist and a Senior Technical Specialist at GZA GeoEnvironmental, Inc. With 25 years of experience, his focus is on groundwater flow modeling, fate & transport modeling, aquifer testing design and evaluation, and hydrologic evaluations. www.gza.com, matthew.gozdor@gza.com

by Tony Finding,CHMM, Brownfield Science & Technology, Inc. (BSTI)

When your in-situ environmental remediation system goes live, it might feel like the hard part is over. The installation is complete, the contractors have cleared out, and regulators are off your back. But a quiet site doesn't mean it's time to take your eye off the ball—especially when it comes to operations and maintenance (O&M) costs.

Based on over three decades of designing, building, and operating remediation systems, here are ten professional strategies to ensure your O&M dollars are working hard—every year of your project.

1. Know Your Endgame Before You Start

Don't just focus on cleaning up contamination—consider whether you need to clean it up at all. Regulatory endpoints based on risk assessments can allow for scaled-back remediation if human or environmental risks are minimal. Even with an active system, a fresh look at your endpoints might reveal you're closer to closure than you think.

2. Design with O&M in Mind

System designers often over-engineer for peak contamination. But as mass removal rates decline, you're left operating an oversized system at full cost. Request cost projections for both early and steady-state phases, and push for lifecycle budgeting that highlights long-term expenses. Design choices—like centralized monitoring points—can significantly reduce site time and improve data quality.

3. Use the Right Tool for the Right Job

Remediation often starts with aggressive “hammer” solutions. But as contaminant levels drop, those systems can become excessive and inefficient. Adaptive site management lets you switch to more targeted “Q-tip” solutions later on, potentially saving thousands without compromising outcomes.

4. Choose Skilled Operators, Not Just Warm Bodies

An experienced system operator does more than read meters—they monitor trends, anticipate problems, and fine-tune performance. If your system experiences frequent downtime or surprise repair costs, you might have a “meter reader” instead of a true O&M professional.

5. Beware of the “Lowest Cost” Trap

Competitive bidding can drive down hourly rates, but if each new contractor delivers diminishing returns, the long-term cost may be higher. Operators who lack incentive to close out a site might prolong a project indefinitely. Invest in quality service, not just low rates.

6. Follow the Money: Understand Your Spending

Dissect your budget. Are your dollars going to energy-hungry systems with minimal output? Are you collecting redundant data? Is fouling causing frequent failures? Understanding cost drivers helps you prioritize solutions and streamline your program.

7. Match Technology to the Phase

Early on, robust renewable technologies (like thermal oxidizers or soil vapor extraction) are efficient. But as contaminant levels drop, consumables like activated carbon might be cheaper. The key is knowing when to switch. A good operator can help optimize timing based on treatment cost per mass removed.

8. Embrace Telemetry and Remote Monitoring

Simple telemetry systems offer huge savings. They alert you to faults in real time and reduce the need for routine site visits. They also allow techs to show up prepared, cutting down on costly return trips. Smart monitoring prevents unnoticed downtime—days, even weeks—that delay progress and inflate costs.

9. Don’t Get Distracted by “Bells and Whistles”

Not every automation is worth the price tag. While some features are essential (like remote valve control for high-risk sites), others add cost without value—and sometimes even create new maintenance burdens. Evaluate your system needs critically to avoid over-engineering.

10. Schedule Annual Optimization Reviews

No system performs exactly as designed. Conditions change—water tables shift, surface cover alters, infrastructure evolves. An annual review with your operator ensures you adapt to these changes. It’s a powerful opportunity to reassess system performance and capture savings year over year.

The Author:

Tony Finding, CHMM, serves as Vice President and Director of Remediation Technologies at Brownfield Science & Technology, Inc. (BSTI). With over 25 years of experience in environmental consulting, Tony is a Certified Hazardous Materials Manager and a leading expert in environmental remediation system design, implementation, and optimization. He has directed the successful completion of more than 300 remedial projects across the Mid-Atlantic region, bringing deep expertise in technologies such as in-situ chemical oxidation, bioremediation, and advanced groundwater treatment. Tony is also a recognized leader in the assessment and remediation of PFAS and other emerging contaminants, and has contributed to national technical guidance through the Interstate Technology and Regulatory Council (ITRC). Contact: Tony Finding, V.P., Director of Remediation Technologies Email: tfinding@bstiweb.com Phone: (610) 593-5500 Website: www.bstiweb.com

by Lindsay Boone, M. Sc., Pace Analytical Services

The reclamation and redevelopment of brownfield sites represent a critical opportunity to breathe new life into underutilized spaces. However, a thorough site assessment is essential to understanding a site’s past usage and the potential it presents for future liabilities. Furthermore, the designation of PFOA and PFOS as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) has made PFAS a critical component of any site redevelopment assessment. 

In this article, we discuss the primary test methods used to analyze PFAS in environmental matrices with the goal of arming readers with the insights they need to chart a clear path forward.

Test Methods for Brownfields Analysis

For the purposes of brownfield redevelopment, an environmental analysis can cover a variety of matrices, such as groundwater, surface water, stormwater runoff, soil and more. In 2024, the U.S. EPA finalized EPA 1633, providing the industry with a standardized, validated method for analyzing targeted PFAS compounds in non-potable aqueous and solid matrices.  

We are seeing the EPA as well as state agencies utilize 1633 in programs in National Pollutant Discharge Elimination System (NPDES) permitting. The Department of Defense (DOD) has also relied heavily on EPA 1633 for PFAS remediation projects when analyzing non potable matrices.  Yet, while EPA 1633 may be used for brownfield site assessments, these projects do not always involve direct EPA or DOD oversight. This allows project managers in some cases to leverage other test methods for analyzing PFAS in environmental matrices.

An alternative method, ASTM D8421, was developed by the American Society for Testing and Materials to provide the industry with a quick, easy, and robust method for PFAS in non-potable aqueous matrices. This method was validated using reagent water and tested with difficult matrices including landfill leachate, metal finisher wastewater, Publicly Owned Treatment Work (POTW) influent and effluent, and other non-potable water. 

The ASTM D8421-22 documentation describes the method this way: This test method covers the determination of per- and polyfluoroalkyl substances (PFASs) in aqueous matrices using liquid chromatography (LC) and detection with tandem mass spectrometry (MS/MS). These analytes are co-solvated by a 1+1 ratio of sample and methanol then qualitatively and quantitatively determined by this test method. Quantitation is by selected reaction monitoring (SRM) or sometimes referred to as multiple reaction monitoring (MRM).  

ASTM D8421 provides several advantages over EPA 1633: 

• Turnaround time (TAT) is typically faster than more procedurally complex methods like EPA 1633.
• ASTM D8421 is typically a less expensive test to perform than EPA 1633.
• ASTM D8421 is a low-volume test, requiring only three containers of 5 ml each. This makes sample collection and shipping easier and less expensive.
• ASTM D8421 has been validated for 44 PFAS. This includes the 40 PFAS quantifiable by EPA 1633 plus PFPrA, a short chain PFAS, and TFSI, a compound of interest in DOD projects.
• Technically similar to EPA 8327, either method can be cited.
• ASTM D8535 is technically similar to ASTM D8421. Pace® has validated this method for analyzing PFAS in soil and other solids.

ASTM D8421 is a “performance-based” method, meaning it can be adapted or optimized for specific projects or analytical goals. Pace® added isotope dilution which is also used for quantification in EPA 1633.

Is ASTM D8421 a Screening Method?

The short answer to this question is no. However, “screening method” is a user-defined term without a universal understanding or definition. At its essence, ASTM D8421 is a definitive method. There is some confusion regarding the capabilities and ability of ASTM D8421 to meet specific Data Quality Objectives (DQO). To clarify, it is essential to understand the difference between a “screening method” and a “definitive method.”

Definitive test methods deliver data suitable for final decision-making (of the appropriate level of sensitivity, precision, and accuracy) and legally defensible. These methods are typically developed in accordance with rigorous scientific standards to ensure they provide consistent, reproducible results that accurately reflect the presence and concentration of PFAS compounds. Definitive test methods require a precision and bias statement.  

Screening methods produce data that can support an intermediate or preliminary decision but should eventually be supported by definitive data. For example, EPA 1621 is defined by the EPA as a screening method as it only “estimates” the concentration of AOF (adsorbable organic fluorine) in a sample. ASTM D8421 can certainly be used by various stakeholders to meet screening-level DQOs; but at its essence, ASTM D8421 is a definitive method.

Interesting Developments Are on the Horizon

Interestingly, the landscape for PFAS test methods can change even faster than the regulations, and there are some interesting developments in the works. As expected, the EPA has proposed adding EPA 1633 to 40 under Methods Update Rule 22, further cementing the use of these methods in EPA regulatory actions. 

Just as importantly, MUR 22 also proposes incorporating ASTM D8421 by reference. “By reference” simply means that the Congressional Federal Record (CFR) will link out to documents authored by the standards body that developed the method instead of including all details in the CFR. This relieves at least some of the documentation burden for the agency. Once ASTM D8421 has been incorporated as a “Part 136” test method, the EPA can incorporate it into other Clean Water Act (CWA) regulatory programs if it so chooses. 

The Author:

Lindsay Boone, M.Sc.  is a PFAS Technical Specialist at Pace® Analytical Services and frequent speaker on PFAS-related issues including treatability and remediation studies.

These standards may apply to sites undergoing remediation as well as sites that have been closed

By Kristen English and Mindy Sayres, PG, LSRP, GZA GeoEnvironmental, Inc.

If you’re wondering what the New Jersey Department of Environmental Protection’s (NJDEP’s)  updated Ground Water Quality Standards (GWQS) mean for you as an environmental consultant, site owner, or prospective site owner, here are some key points to consider.

Background

NJDEP amendments to the GWQS changed the criteria for 73 compounds, including 50 that were made more stringent. Of those, the GWQS of seven compounds have been decreased by an Order of Magnitude (OOM) or more.  Effective February 3, 2025, these standards apply to Class II-A groundwater, which is essentially all groundwater in New Jersey.  It has been estimated that thousands of sites, both active and closed, will be impacted. 

What are the Order of Magnitude compounds?

The seven compounds for which standards have been decreased by an OOM or more—at least 10x more stringent—are: 1,1-Biphenyl; Cobalt; Free Cyanide; 1,3-Dichlorobenzene; Heptachlor Epoxide; Methoxychor; and Vinyl Chloride.  

How do these new standards change what is required at my site where remediation is underway?

• If a remedial action workplan (RAW) or remedial action report (RAR) is submitted by August 3, 2025, the former GWQS remain in effect, except for those seven compounds with OOM changes. It is imperative that an evaluation be completed for those seven compounds to determine if groundwater concentrations remain in compliance and protective of human health and the environment. If they do not meet the new standards, additional investigation and/or remediation may be required. 
• At sites where the RAW/RAR have not been submitted by August 3, 2025, the new GWQS will apply.

An RAO was issued for my site – will the case be reopened?

There has been much discussion in the environmental community in the short time since the GWQS were published as well as in the comments/responses of the newly published GWQS about potential “reopener” triggers for cases that have been closed, i.e., have a Response Action Outcome (RAO) or No Further Action (NFA). Indeed, the science of each site varies, and environmental consultants will work closely to advise their clients appropriately as these scenarios are further explained by the NJDEP.

Thus far, in response to multiple comments included in the February 3, 2025 New Jersey Register publication of the new GWQS regarding the potential for cases with a final remediation document to be reopened, the NJDEP response has included the following information:

• For sites with a Restricted-Use RAO or Limited Restricted-Use RAO with an approved Groundwater Remedial Action Permit, an OOM evaluation for the seven compounds noted above must be conducted and included with the next Biennial Certification submittal. Depending on the results of that evaluation, additional actions may be required. 
• If a site has been closed with an unrestricted RAO or an unrestricted NFA, the OOM evaluation would be required if/when the site “re-enters” the NJDEP’s Contaminated Site Remediation and Redevelopment (formerly named the Site Remediation Program), which could be prompted by a property transaction or other triggers.

What are the most common constituents for which standards have been made more stringent?

In addition to Vinyl Chloride (one of the seven compounds for which the standard has decreased by an OOM), three of the 50 compounds for which standards have become more stringent and which are very commonly found on contaminated sites in New Jersey include:  Benzene; Tetrachloroethene; and Trichloroethene.  These compounds are often present in groundwater at sites in New Jersey impacted by historical uses such as dry cleaners, gas stations/auto repair shops, and industrial and manufacturing facilities that used solvents in their operations, to name a few.

What if the site I am considering purchasing is contaminated?

Environmental due diligence, including a Preliminary Assessment (PA) and, if necessary, a Site Investigation (SI), remains critical for buyers in New Jersey to make informed property transaction decisions. This investigatory process demonstrates that the buyer has conducted “all appropriate inquiry” and entitles the buyer to “innocent purchaser defense” under the Spill Act; this can protect the buyer from responsibility for additional evaluation requirements or costs associated with the new GWQS. Compliance with the new GWQS is the responsibility of  the Person Responsible for Conducting Remediation (PRCR), as determined by New Jersey’s Spill Act and/or Brownfield Act. 

The Authors:

	Kristen English is a Senior Project Manager at GZA with more than 25 years of experience in the environmental field. Her expertise lies in soil and groundwater remediation at hundreds of sites throughout the Northeast including brownfields and UST closures. Kristen.English@GZA.com
	Mindy Sayres, PG, LSRP is a Senior Vice President of GZA and the District Office Manager of the firm’s Fairfield, NJ office. She has more than 30 years of environmental consulting experience, leading project teams tackling complex geologic, hydrologic and contaminant investigations.  Mindy.Sayres@GZA.com

By Ryan Givens, AICP, Montrose Environmental

The U.S. Government Accountability Office (GAO) reports over 1.5 million abandoned properties across the U.S. – creating voids and a sense of abandonment in our cities and local communities.  These sites, including industrial buildings, office parks, and waterfronts, have potential to be reimagined as new community-serving destinations through resolute revitalization planning strategies. A clear vision is crucial for revitalization, involving community members, leaders, and experts to identify opportunities and set a trajectory for change

Key Approaches:

Adaptive reuse involves converting and modernizing existing structures.

• Convert old buildings into residential units or commercial spaces.
  
• Challenges include upgrades and compliance with safety standards.
  

Urban infill entails building new opportunities on vacant urban lots.

• Develop new projects on vacant urban lots, integrating with the surrounding area.
• Challenges include limited space, parking, and potential environmental issues.

Redevelopment means replacing outdated sites with transformative developments.

• Replace outdated structures with new developments.
• Examples include transforming vacant shopping centers and industrial plants.

Public realm enhancements include upgrading streets, parks, and public spaces.

• Add landscaping along public streets, repair sidewalks and create recreational amenities.
• Challenges include funding for enhancements.

Strategy Tips for Successful Revitalization:

1. Adapt Regulatory Tools: Amend zoning and building codes to accommodate and entice investment.
2. Identify Infrastructure Upgrades: Assess and upgrade infrastructure to support redevelopment projects and support new tenants.
3. Resolve Environmental Barriers: Identify and address contamination and hazardous substances to ready sites for redevelopment and reuse.
4. Secure Funding: Identify funding sources for revitalization projects.
5. Rebrand and Market: Rebrand areas to attract new investors, residents, and visitors.

By incorporating these strategies, communities can transform abandoned properties and distressed neighborhoods into thriving, sustainable environments.

Tools and Resources

• EPA Brownfields Program: FY 2025 Brownfields Job Training Listening Sessions
• Case Studies on Urban Revitalization: World Bank Report on Urban Revitalization
• Current Vacancy Rates in the U.S.: Census.gov - Housing Vacancies and Homeownership

The Author:

Ryan Givens, AICP, is a dedicated City Planner and Urban Designer with 24 years of experience in community design, master planning, and revitalization strategies. Passionate about urban places, Ryan specializes in land use planning, urban infill, and redevelopment, focusing on transforming neglected properties into vibrant community assets. His expertise in environmental assessments, infrastructure planning, and funding strategies ensures successful project implementation, making him an invaluable partner in revitalizing neighborhoods and commercial districts.