Derek A. Pizarro¹ , Thomas P. McCullough² , Gary J. Meyer²

1. INTRODUCTION

The introduction of reactive iron species for treatment of inorganic contaminants is well known, yet the efficiencies of these various irons – zero valent iron (ZVI), ferrous or ferric sulfate, and iron sulfides, differ greatly in reactivity, efficiency, and cost. One group of reactive iron species are “reactive iron sulfides” which have been successfully used for the reduction and precipitation of inorganic contaminants such as chromium, arsenic, and mercury. 

This memorandum focuses on the use of a particular subset of reactive iron sulfides - mackinawite structured iron sulfide and sulfonated iron-aluminum layered double hydroxide (LDH), collectively referred in this paper as “FeS”. 

Another standalone reductant the environmental remediation industry has long studied and recognized for its usefulness is ZVI. However, ZVI may have its own set of constraints, limitations, and variabilities in successfully meeting remediation goals when deployed at a particular site. In addition, compared with these forms of FeS, ZVI is less chemically efficient (due to passivation) and persistent in the environment than other FeS. 

These constraints, limitations, and variability in success when using ZVI are related to many factors, including but not limited to: 

• The iron source used to manufacture the ZVI itself
• Particle sizing of the ZVI
• Low reactivity due to its intrinsic passive layer
• Narrow working pH
• Reactivity loss with time due to the precipitation of metal hydroxides and metal carbonates
• Low selectivity for target contaminants (especially under oxic conditions)
• Limited efficacy for treatment of some refractory contaminants
• Passivity of ZVI arising from certain contaminants
• Geochemical variability between sites and even within sites location (Guan, 2015).

To counteract some of these challenges, during the past decade, ZVI reagent providers have begun to sulfidate (sulfonate) their ZVI, chiefly with the intent is to increase the ZVI’s reactivity, selectivity, and longevity for various reductive processes. Although these sulfidated or sulfonated ZVIs (S-ZVI) have become a more commonly used product for both inorganic and organic contaminant reduction applications, consistently meeting a site’s long-term remediation goals has remained elusive.   

2. FERROUS SULFIDE CREATION 

Multiple university and industry research papers have proven that FeS can be generated abiotically (chemically) or biotically (biogeochemically) (Wang et al., 2024, Mangayayam et al., 2019).  While the formation of a stable, highly reactive FeS is possible in both abiotic and biotic scenarios, there are significant performance differences between chemically synthesized FeS (abiotic FeS) and biogeochemical generated FeS (biotic FeS)

Biogeochemically generating ferrous sulfides in-situ for site remediation has become a more prevalent practice in the past decade and a half, primarily based upon the research and evaluation of sulfate-rich aquifers with sulfate-reducing microbes that produced free sulfide (Rickard 2012 and Picard et al., 2018). The introduction of an iron component for oxidation and reaction with this free sulfide produced in these environments completed the FeS formation process. It is interesting to note that this concept traces its roots back to paleo-geochemical environments where biotic FeS was generated in low-temperature, anoxic surface water and groundwater settings by sulfate reducing microorganisms (SRM) (Wacey et al., 2015). In both settings, sulfate is utilized as an electron acceptor by indigenous or imported facultative microbes that produce (hydrogen) sulfide. This reductive metabolic process is known as biosulfidogenesis (Jameson et al., 2010).

This concept of biologically produced sulfide combined with an iron source has evolved over the years into the practice of mixing S-ZVI with microbes to jumpstart this process or provide the necessary components to facilitate the reaction and precipitation of iron sulfides, most notably for reductive dechlorination applications.  

More recently, it has become common for environmental practitioners to optimize this biotic formation of FeS by adding additional nutrients and kinetic additives to condition the aquifer and promote more optimal geochemical conditions that improve the speed, efficiency, and quantity of FeS produced biogeochemically. This combined injectate has been referred to as S-ZVI and enhanced reductive dechlorination (ERD), (SZVI+ERD), S-ZVI and enhanced in situ bioremediation (EISB) (S-ZVI+EISB), or S-ZVI and anaerobic bioremediation (AB), (S-ZVI+AB). 

Even with these advancements mentioned, one of the greatest challenges to overcome in these types of biogeochemical systems is the amount of time (and timing) required to create the desired environment for successful remediation. 

Many chemical and biological processes must occur concurrently and sequentially over a period of months to generate the quantity and type of FeS required. Some of these processes include the transformation and maintenance of the aquifer into a sulfate-reducing environment depleted of dissolved oxygen to promote biosulfidogenesis. This biosulfidogenesis must be coupled with oxidation of the iron source (e.g., ZVI) to produce several iron oxide species plus ferrous iron, and all these processes must be present and maintained for direct microbial interaction and formation of FeS. Additionally, the availability of sulfate (total or mass flux) also has a direct bearing on the formative size, iron morphology, and mineralogy of the iron sulfide; again, influencing the reactivity and mass of FeS generated. 

While earlier laboratory studies (Rickard, 1969) inferred that biotic FeS did not physically differ from abiotic FeS, more recent research suggests that this is not necessarily the case. Over the past five decades, more sophisticated laboratory experiments confirmed the issues with verifying the viability of usable biotic FeS and have found that non-reactive species of FeS may be generated (e.g., pyrite, greigite) and not the quantities of the reactive FeS desired. 

Using modern laboratory technologies, the physical and chemical characteristics (i.e. crystal size, morphology, texture, solubility) of the minerals formed in the presence of sulfate-reducing microorganisms (SRM) “have not been thoroughly investigated” and were “likely limited by the technology available at time” (Picard et al., 2018). Further, several factors influencing the ability of SRM to biotically form reactive FeS were highly affected by the geochemical setting- mainly influenced by the geological environment and anoxic conditions. Thus, the generation (derivation) and reactivity/utilization (consequence) of these biotic compounds can be more readily predicted in modern experiments where instrumentation is more appropriate for in-depth analysis, but also the equipment can control environmentally germane factors that play a role(s) in biotic FeS formation. 

3. STRUCTURAL DIFFERENCES

Iron sulfide mineralization experiments examining the influences of several biogenic parameters on the formation of biotic FeS after one week of incubation and then monthly for one year revealed significant structural differences. These biotically formed FeS particles were compared to abiotically prepared FeS at the same Fe:S ratios (Picard et al., 2016).  

Scanning Electron Microscope (SEM) images of biotic (upper row) and abiotic (lower row) iron sulfide precipitates, washed and air-dried in an anaerobic chamber, after one week of incubation.  (from Picard et al., 2018)

The Picard, et al., 2018 team concluded the following: 

1. Despite having similar Fe:S ratios and formed at similar pH, the mineral precipitates formed under biotic and abiotic experiments had visually distinct bulk morphologies.
2. Biotic precipitates appeared less opaque (i.e. absorbed less light) than abiotic precipitates.
3. After the minerals settled back to the bottom of the vials, the precipitates formed in biotic Fe experiments formed a sticky aggregate, while abiotic precipitates appeared finer and more homogeneously distributed. 
4. Precipitates in the biotic treatments aggregated more than the abiotic precipitates and thus formed larger particles. Aggregates of biotic particles in solution were much larger (1354 ± 120 nm) than abiotic aggregates (428 ± 148 nm). 
5. The massive aggregation of biogenic iron sulfide minerals is consistent with observations of ‘sticky’ mineral precipitates in the serum vials. 
6. The binding of Fe2+ to microbial compounds before the precipitation of FeS seems to play an important role in determining the final properties and morphology of iron sulfide minerals.
7. Different mineral morphologies are observed when minerals precipitate in the presence of dead SRM.

Overall, the application and applicability of these “controlled” laboratory experiments to actual remediation applications assumes the ability to efficiently create biotic FeS in an “uncontrolled” environment.  This means that: 

• Since the increased surface area (smaller sized particles) and uniformity within the structure has a direct impact on reactivity in-situ, and
• The distribution and reactivity of the biotically formed FeS in-situ is hampered by agglomeration and massing, abiotically formed FeS would be favored.

4. IMMEDIATE REMEDIATION

Deploying an abiotically, manufactured (chemically synthesized) FeS presents several advantages and resolutions to the limitations of the biogeochemically generated version. An FeS synthesized with an excess of sulfide (S-FeS) exhibits a larger interlayer spacing and unit cell volume that contains an interlayer of polysulfides which is structured is a wave pattern that has a greater surface area for contaminant reduction, degradation, and/or removal (Wang, et al., 2024). 

• Abiotically produced FeS (e.g., S-FeS) is not dependent on biogeochemical processes.
• Pyrite and greigite are not formed or introduced to the system, a conversion process which depletes the reductive setting.
• Phosphate in the geochemical setting does not retard or inhibit the formation of these types of abiotically produced FeS (or S-FeS) – the phosphate mineral complex (vivanite) is not a chemically available form of FeS.
• Extracellular materials, byproducts of microbial respiration, do not aggregate and produce irregular or outsized FeS particles.
• Agglomerated FeS particles are not present, which may reduce aquifer porosity.
• Multi-metal contaminants, or commingled inorganic and organic contaminants, settings do not shift the production or reactivity of the abiotically produced FeS which may occur during biotic FeS formation.

5. CONCLUSIONS

Biogeochemically generated FeS has gained acceptance in the environmental remediation industry for groundwater remediation of inorganic and organic contaminants. The introduction of bioremediation components with S-ZVI to generate FeS in situ is a demonstrated technology. A chemically manufactured version (S-FeS) has also been utilized with prevalence in recent years in similar deployments. It has proven to be effective immediately and demonstrate subsurface persistence. 

The differences in these two FeS materials, outside of performance and timeframe, are also realized in project cost and timeline. The intent of proponents of biotic FeS is to reduce the cost of the injectate on a per pound basis. Yet, because of many in situ factors, it is difficult to estimate the total mass of FeS that will be generated, even if conditions remain constant and optimal, which is difficult to control longer than weeks or months in most cases. The agglomerate structure is also not conducive to high-capacity reduction or degradation. With S-FeS, the weight of available irons and sulfides is straightforward to calculate and evaluate on a stoichiometric and cost basis. 

References

Guan X, Sun Y, Qin H, Li J, Lo IM, He D, Dong H. The limitations of applying zero-valent iron technology in contaminants sequestration and the corresponding countermeasures: the development in zero-valent iron technology in the last two decades (1994-2014). Water Res. 2015 May 15; 75:224-48. Epub 2015 Feb 28. 

Jameson, E., O.F. Rowe, K.B. Hallberg, and D.B. Johnson. Sulfidogenesis and selective precipitation of metals at low pH mediated by Acidithiobacillus spp. and acidophilic sulfate-reducing bacteria. Hydrometallurgy, Volume 104, Issues 3–4, 2010, Pages 488-493.

Mangayayam, M., J.P.H. Perez, K. Dideriksen, H. Freeman, N. Bovet, L.G. Benning, and D. Tobler. 2019. Structural transformation of sulfidated zero valent iron and its impact on long-term reactivity. Environmental Science. Nano. (00):1-9. 

Picard, Aude, Amy Gartman, and Peter R. Girguis. "What do we really know about the role of microorganisms in iron sulfide mineral formation?" Frontiers in Earth Science 4 (2016): 68.

Picard, Aude, Amy Gartman, David R. Clarke, Peter R. Girguis. Sulfate-reducing bacteria influence the nucleation and growth of mackinawite and greigite. Geochimica et Cosmochimica Acta, Volume 220, 2018, Pages 367-384.

Rickard, David. Chapter 8 - Microbial Sulfate Reduction in Sediments, Developments in Sedimentology, Elsevier, Volume 65, 2012, Pages 319-351.

Wacey, David, Matt R. Kilburn, Martin Saunders, John B. Cliff, Charlie Kong, Alexander G. Liu, Jack J. Matthews, and Martin D. Brasier. "Uncovering framboidal pyrite biogenicity using nano-scale CNorg mapping." Geology 43, no. 1 (2015): 27-30.

Wang, Chunli, et al. A novel Iron Sulfide Phase with Remarkable Hydroxylradical Generation Capability for Contaminants Degradation. Water Research 251 (2024): 121166.

Conflict of Interest Statement

Derek Pizarro declares no conflicts of interest. Thomas McCullough and Gary Meyer are the owners of Redox Solutions, LLC, which owns the intellectual property and manufacturing facility for a commercialized mackinawite structured iron product (FerroBlack®). 

¹AST Environmental, Inc. Freehold, New Jersey, USA.

²Redox Solutions, LLC. Carmel, Indiana, USA. 

The Author:

Derek Pizarro is a Senior Product Manager at AST Environmental, Inc. and a Certified Professional Geologist. He has 22 years of experience in environmental remediation, specifically contaminant transport studies, fractured bedrock characterization and injection, and reagent bench-scale testing and design for environmental sites and industrial process waste streams. Before joining AST, Derek was a Product Director and GM for an environmental chemical manufacturer, with previous experience in environmental consulting and bedrock services. He received a Bachelor of Science in Geology and Environmental Geosciences from Lafayette College. AST Environmental, Inc. (Freehold, NJ) is an internationally recognized leader in injection and environmental construction services, specifically known for groundwater remediation and in situ injection using proprietary subsurface distribution techniques. As a privately held small business, AST thrives as an integral, specialized part ofproject teams, focusing on supporting consultants, responsible parties, and stakeholders dealing with challenging environmental impacts in overburden, transition zones, and fractured bedrock. www.astenv.com

by Adam Henry, P.G., LEP, GZA GeoEnvironmental

On March 1, 2026, the Connecticut Transfer Act, which has been one of the primary drivers of environmental cleanup of polluted properties for more than 40 years, will sunset. After March 1, 2026, requirements for cleanups will no longer be triggered as a result of the transfer of an “establishment” and responsible parties will no longer be required to conduct site-wide investigations to “prove the negative.” However, responsible parties that already have Transfer Act obligations will still be required to complete them.

Starting March 1, 2026, the new Connecticut Release Based Cleanup Regulations (RBCRs) will require cleanup of pollution when it is discovered, similar to what is currently required in most other states. Discovery can occur when soil or groundwater samples collected March 1st or after identify pollution. Discovery can also occur when “multiple lines of evidence” are observed, including soil staining, odors, or urban fill material or information is available regarding historical testing data (however, a “filing cabinet exemption” exists for environmental reports/data issued prior to March 1, 2026).

When pollution is discovered, the RBCRs require the responsible party to complete cleanup of the polluted area within 120 days or report the pollution to the Connecticut Department of Energy and Environmental Protection (CTDEEP), or sooner if pollution is significant. If compliance with the RBCRs is not achieved within one year, the polluted area must be assigned to a “cleanup tier”, annual fees are required depending on the severity of the condition and deadlines for cleanup are applicable.

The transition from the Transfer Act, which regulates a relatively narrow subset of properties, to the RBCRs, which will apply to pollution discovered at all properties, represents a sea change in how environmental cleanups in Connecticut are completed and will have significant implications for how due diligence is conducted, construction projects are planned, and environmental information is managed.

The Author:

Adam Henry, P.G., LEP Mr. Henry, an Associate Principal of GZA GeoEnvironmental, Inc., leads the firm’s Buildings and Real Estate Development sector. He has over 20 years of experience managing site assessments, investigations, and remediation projects. He also works closely with lenders, developers, business owners and attorneys to complete their environmental due diligence during real estate acquisitions, divestiture and refinancing. If you have questions about how the new regulations may impact your business or property, please contact him at Adam.Henry@GZA.com or 860-858-3166.

by Sarah Sieloff, Haley & Aldrich

On December 12th, EPA-funded technical assistance provider the Redevelopment Institute hosted a webinar about US manufacturing, lack of land, and brownfield redevelopment. The following post provides a summary with links to resources.  A recording of the webinar is available here.

After decades of decline, US manufacturing investment is on the upswing, and manufacturing investments worth tens of millions to hundreds of billions of dollars are landing across the nation. Often, that’s happening in smaller and mid-sized communities. The reasons are complex and span federal incentives, shifting geopolitics and lessons learned following the global pandemic. For example, on December 10th, Eli Lilly announced a $6 billion pharmaceutical manufacturing investment in Huntsville, Alabama, and similar commitments are coming to many communities from companies ranging from Toyota and Hyundai to yogurt producer Chobani. 

But there’s a hitch: the US lacks the development-ready land necessary to accommodate this investment. According to the 2025 State of Site Selection Report, 49% of site selectors identified the availability of development-ready sites as a limiting factor. For Michael Taylor, brownfields redeveloper, president of Vita Nuova, and webinar speaker, this indicates that now is the time for local governments and private investors to coordinate planning to facilitate future investment, as site selectors—one of whom referred to a “manufacturing renaissance”— describe new levels of demand for project-ready sites. 

Each major manufacturing investment needs land, and so does its infrastructure, suppliers with warehouses and logistical requirements, workers, and workforce housing. Mark Williams, author of Corporate Site Selection and Economic Development, estimates that an investment anticipated to create 4,000 manufacturing jobs will generate 11,600 supplier jobs. Anticipating each supplier job requires 1,200 square feet of space, that adds up to 1,065 acres (1.66 square miles) needed to accommodate the original manufacturing facility and the ecosystem that surrounds it. 

Critically, those 1,065 acres don’t need to come in the form of a megasite. In the 2025 State of Site Selection Report, site selectors emphasize the need for sites of varying size, from 5 acres to 150 acres, with utilities and clear development timelines.  

Whether urban or rural, few places in the US have enough development-ready land today, but brownfield redevelopment could change that. With the final year of historically large EPA Brownfields grants upon us, and applications due January 28 of 2026, now is the time for local governments to think hard about how land reuse can improve their readiness to receive manufacturing investment. 

Brownfield redevelopment fueled by EPA grants can provide an answer

EPA is currently accepting applications for $255.7 million in Brownfields grants, which can support environmental assessment, cleanup, planning and community engagement. Most public and nonprofit entities are eligible to apply, and although private sector entities can’t directly receive this funding, they can still benefit from Brownfields grants by partnering with public and nonprofit applicants.

This year is significant because it is the final year in which funding from the 2021 Bipartisan Infrastructure Law (BIL) will make historically large Brownfields grants possible. The BIL effectively tripled available EPA Brownfields funding by investing $1.5 billion over five years (FY22-FY26). However, all BIL funds must be obligated by September 30, 2026, after which Brownfields grants will reduce in number and size.  

While we often talk about Brownfields as an environmental program, Brownfields grants are really about redevelopment. They support planning activities that generate reduce uncertainty and generate redevelopment momentum, from market feasibility studies to infrastructure assessments and fiscal and economic impact estimates. Done well, planning under a Brownfields grant can start conversations about public-private partnerships, and help articulate a pathway to redevelopment. Table 1 shows examples of planning activities that can be funded by EPA Brownfields grants. For more information about specific Brownfields-support planning activities, check out these factsheets from EPA. 

Table 1. How can you plan under an EPA Brownfields grant?

EPA values planning so highly that it evaluates assessment grantees on whether they allocate at least 30% of their proposed grant budgets to planning activities. Planning facilitates redevelopment because it clarifies local preferences and expectations, and can mitigate project opposition, which can cause costly delays. 

EPA Brownfields grant applications are due January 28, 2026, and it’s not too late to start. 

The Author:

Sarah Sieloff, Planner, Haley & Aldrich Sarah Sieloff is a planner with Haley & Aldrich, an integrated, multidisciplinary consulting firm. Based in Bellingham, Washington, Sarah helps public and private sector clients around the US build more sustainable, livable futures by navigating and effectively addressing brownfield redevelopment, climate resilience, environmental justice concerns and state and federal funding.

Sarah DeStefano, ENV SP

The redevelopment of Ryan Park and Soundview Landing in South Norwalk, Connecticut (“SoNo”) transformed nearly seven acres of environmentally impaired and flood-prone land into a climate-resilient public park and a vibrant mixed-income housing community. Once home to Connecticut’s oldest public housing development and the only recreational public space in SoNo – which was closed in 2016 due to elevated PCB levels - the area has been reimagined as a sustainable neighborhood anchor that now offers safe housing, green space, climate resiliency, and economic opportunity.

Historical maps of SoNo show the area was originally mud flats and marshland near Norwalk Harbor that were filled and developed into a mixed industrial and residential neighborhood in the late 1800s. Its low-lying geography, however, made it vulnerable to flooding and contributed to decades of disinvestment in this historically distressed and disadvantaged neighborhood.

By 1940, a portion of the area was cleared for what would become Washington Village (since renamed Soundview Landing), a city-owned residential complex of 11 buildings. Over time, surrounding areas were converted into storefronts and office space, most of which were demolished by the late 1950s. The neighborhood suffered from reoccurring flooding, including severe damage from Hurricane Irene in 2011 and Superstorm Sandy in 2012, prompting the Norwalk Redevelopment Agency to secure a 2014 HUD Choice Neighborhood Grant to help address these concerns.

The vision for SoNo emerged from an 18-month community planning process supported by the Choice Neighborhood Grant. Residents, businesses, and elected officials collaborated to shape a roadmap for neighborhood improvement, focusing on environmental justice, housing equity, and economic opportunity. The Norwalk Redevelopment Agency subsequently secured a U.S. EPA Community Wide Brownfields Grant to assess contamination and plan a fair and equitable cleanup and revitalization process. In addition, multiple cleanup grants totaling $5.7 million were obtained from the Connecticut Department of Economic Community Development (CTDECD) to address contamination at both the Ryan Park and Washington Village project locations.

Remediation and design strategies included:

• Removal of over 30,000 tons of contaminated soil
• Construction of engineered soil caps
• Petroleum recovery and underground infrastructure upgrades
• Elevation of streets and greenspace by 2–6 feet above the 500-year floodplain, exceeding FEMA standards

Ryan Park was restored and elevated to provide dry egress during storm events and now features modern recreation facilities, walking paths, and flood protection, along with new playgrounds and landscaping. Adjacent to the park, the new Soundview Landing development was raised by more than eight feet above the flood zone. The regulatory closure of Ryan Park was documented through state and federal approvals, while Soundview Landing was enrolled in the Connecticut Voluntary Remediation Program, with environmental land use restrictions and Site Verification Reports confirming compliance with the state’s Remediation Standard Regulations

All 136 affordable housing units were preserved and 137 additional moderate-income and market-rate units were added, promoting income diversity and expanding access to better health, education, and employment outcomes. The redevelopment was one of the first in Connecticut to blend 9% and 4% Low Income Housing Tax Credits, creating a replicable financing model for future projects.

Additionally, the project was driven by robust partnerships across local, state, and federal agencies, catalyzing over $1 billion in additional neighborhood investment. It increased the local tax base, created hundreds of construction and permanent follow-on jobs, and earned sustainability certifications including LEED-ND Silver. 

This multi-year, multi-partner initiative stands as one of Connecticut’s most impactful brownfield-to-community asset transformations. The revitalized Ryan Park and Soundview Landing now draw residents and visitors to the growing SoNo neighborhood, demonstrating how environmental stewardship and inclusive design can help communities thrive.

In recognition of its innovation, impact, and community-centered approach, the Ryan Park and Soundview Landing redevelopment was honored at the 2025 National Brownfields Conference in Chicago with a Phoenix Award, one of the nation’s highest accolades for excellence in brownfield redevelopment.  In addition, the project won the Brownfield Coalition of the Northeast’s (BCONE’s) Brownfield Sustainable Communities Redevelopment Project Award of Excellence.

It took many years and required the resources and partnerships of many individuals to provide a roadmap to move SoNo forward.  The Ryan Park and Soundview Landing redevelopment exemplifies the best of brownfield revitalization: 

• public/private partnerships,
• creative funding stacks,
• innovative engineering and design,
• environmental stewardship, and
• meaningful community impact.

By integrating regulatory requirements with climate resilience strategies and community aspirations, the Ryan Park and Soundview Landing redevelopment has become a model for transformative brownfield revitalization across the Northeast.

The Author:

Sarah DeStefano, ENV SP, Weston & Sampson Sarah is the Environmental Practice Leader at Weston & Sampson. She can be reached at destefanos@wseinc.com.

By Gene Bove, INCE, GZA

Battery Energy Storage Systems (BESS) are being deployed at megawatt- to gigawatt-hour scales to help balance supply and demand, maximize renewable energy utilization, and provide grid stability.

To ensure stable energy delivery to residents, many states have instituted policies and incentives to encourage BESS development.  Once a power purchase agreement is in place, most BESS developers start with two considerations when identifying potential sites: 1. Is there a need for the facility, either to provide backup power or to store energy from renewable resources? and 2. How smoothly can the BESS be connected to the local utility grid?

Once potential sites have been screened for these considerations, developers can select the best possible site by performing some additional evaluations to minimize the risk of encountering costly surprises during design and construction.  

1. When selecting a site for development, conducting a Phase I Environmental Site Assessment (ESA) is a critical step in environmental due diligence. If you are purchasing the property, the ESA provides vital protection against future Superfund or state toxic waste liability claims. Conversely, if you are leasing the site, the ESA establishes an essential environmental baseline, so you are not held responsible for pre-existing contamination. Regardless of ownership, the Phase I ESA can uncover unresolved environmental issues that could impact project development, a concern amplified for multi-state entities dealing with varied and complex environmental regulations and associated liabilities.  “In addition, environmental due diligence can be an important step in project financing,” advises GZA’s Steve Kline. “A Phase I ESA can identify the environmental challenges and benefits of developing potential BESS facilities on either ‘Brownfield’ or ‘Greenfield’ properties.”
2. For BESS site selection, understanding and mitigating noise impact is essential for community acceptance and regulatory compliance. BESS units generate moderate noise; typically a low hum from cooling systems (high-speed fans and cooling systems), power conversion systems (inverters), and electric transformers. This sound, while generally quieter than diesel generators, can add sufficient noise that may violate local noise ordinances, particularly near residential areas. To prevent this, it is crucial to obtain accurate data on existing background noise levels and perform acoustic modeling of the proposed BESS before design, permitting, and installation. “Furthermore, developers must be aware of how local fire codes may limit noise reduction options. For example, fire codes may prohibit noise baffling enclosures, which reinforces the importance of addressing noise compliance requirements and maintain your standing as a ‘good neighbor,’” says GZA’s Ethan Wagner. 
3. Evaluating subsurface conditions for geotechnical design of foundations is vital when selecting a BESS site, given that these units can weigh many thousands of pounds, requiring robust foundation support. As GZA’s Dharmil Patel explains, "getting a clear picture of what’s underground helps you design appropriate foundations to support the BESS, including whether you need to improve the soil, remove rock, or carry loads through soft soils down to firm soils to keep the BESS safe and stable." Understanding these subsurface conditions is paramount for engineering an appropriate and economical foundation. Furthermore, the proximity of abutters must also be factored in, as nearby property lines can significantly complicate foundation and site-preparation requirements.
4. “Environmental Permitting requirements can determine the feasibility of constructing a BESS site,” says GZA’s Julia Braunmueller. “We will typically review available municipal regulations, zoning, and environmental resource data to identify potential issues, such as wetland restrictions, FEMA 100-year flood plains, rare and endangered species habitat, etc., that may result in time delays or significant additional expense. Our approach is to summarize the key attributes of existing conditions, and identify potential issues, listing relevant local, state, and federal environmental and siting permits that are identified during the review for the BESS developer’s consideration.  Based on this review, we will often develop a “permit matrix” of requirements that may be necessary for the development of a BESS facility. The permit matrix will list the responsible agencies, expected permit timeframes, and additional information that may be useful in determining the viability of a site.”

U.S. battery energy storage capacity jumped 66 percent in 2024, according to the U.S. Department of Energy, with projections indicating even faster growth in the coming years. The value proposition is compelling for all stakeholders, from individual building owners to utilities, offering a more resilient power grid and substantial cost savings through arbitrage—storing energy during low-price hours and deploying it to cover peak demands during high-price hours. However, it is a technology where the fast track “no surprises” approach to site selection safeguards against major operational and financial risks. Careful and early evaluation of BESS sites’ environmental, geotechnical, noise, and permitting requirements can make all the difference in fast tracking to project success.

The Author:

Gene Bove, INCE, Sr. Project Mgr., GZA Gene Bove, INCE, is a Senior Project Manager at GZA and a leader in the firm’s acoustic and noise analysis practice. He has been involved in siting and development of BESS sites around the country, including more than 100 in New York State.

By Chris Gdak and Derek Street, Montrose Environmental

The state of brownfields and environmental justice (EJ) in the U.S. has undergone significant changes as of 2025. Following a new administration, the EPA has shifted its focus, impacting communities, developers, and local governments across the Northeast. Here’s an overview of the evolving landscape and what it means for brownfield redevelopment.

Key Historical Context 

Established in the mid-1990s, the EPA’s Brownfields Program has been instrumental in revitalizing contaminated sites through funding initiatives like MARC grants. Concurrently, the EJ Program has sought to empower marginalized communities facing pollution. Significant investments were made in recent years, with the Bipartisan Infrastructure Law allocating $1.5 billion for brownfields and the Inflation Reduction Act establishing numerous EJ initiatives.

Recent Policy Changes 

As of January 2025, the new administration paused IRA and Bipartisan Infrastructure Law funding, resulting in crucial restructuring within the EPA:

• Major reductions in grants and staff dedicated to EJ.
• Dissolution of the Office of Environmental Justice.
• Significant cuts to the EPA budget.
• However, the funding for brownfields has remained intact, creating opportunities for communities ready to act swiftly.

Support for the Brownfields Reauthorization Act in February 2025 has provided some optimism with increased grant caps and allocations focusing on rural and small communities.

Implications for Funding and Future Projects 

The 2025 grant cycle still offers potential for significant funding, emphasizing no-match cleanup grants and increased limits on assessments and cleanups. However, projects targeting Environmental Justice may need to align with broader economic narratives to secure funding.

Looking forward, unless future legislation reverses the current trends, the projected post-Bipartisan Infrastructure Law funding for brownfields is expected to revert to significantly lower levels, estimated between $65 million and $85 million annually. Under these new conditions, grant caps are likely to be around $1 million, and there may be a 10% matching requirement for applicants. The likely focus of future funding will be on economic development, rural areas, and regions facing persistent poverty. Stakeholders will need to align their projects with these priorities to enhance their chances of securing funding in this evolving landscape.

Final Thoughts 

For stakeholders in the Northeast, including communities, governments, and nonprofits, the present moment is crucial. Those with EJ priorities should leverage existing funding opportunities wherever possible, even as they prepare for a more challenging future.

The Authors:

Derek Street - Principal Geologist, Brownfields & Community Revitalization Practice, Montrose Environmental Derek Street is an environmental professional with deep experience in site assessments, brownfield redevelopment, and regulatory compliance. He has worked both in the private sector and at the USEPA, where he reviewed and enforced AAI standards for federal brownfield funding.

Chris Gdak - Practice Leader for Brownfields & Community Revitalization, Montrose Environmental Chris brings 22 years of environmental consulting and brownfield redevelopment experience to his role as Montrose’s Brownfields & Community Revitalization Practice Leader. Chris focuses on assisting municipal, tribal and community-based organizations with building successful programs to achieve their goals. He has assisted clients in over 20 states and has enjoyed learning about each community’s needs and opportunities, developing relationships with local stakeholders, and contributing to the restoration and revitalization of distressed areas.

by Linda Cook, Jill Ready, PG, Steve LaRosa with Weston & Sampson

 “An ounce of prevention is worth a pound of cure.” This well-known statement by Benjamin Franklin, originally penned in the Pennsylvania Gazette in the 1730s to highlight the importance of fire prevention, holds great significance for data quality control in environmental site investigations today. As the science surrounding per- and polyfluoroalkyl substances (PFAS) has grown and evolved, so too has the importance of adequate PFAS data quality control. While the environmental and health risks of PFAS are widely discussed, cost-benefit analyses for poor versus high-quality PFAS data have received limited attention. For brownfield sites in particular, where site assessment and cleanup activities are often being completed with limited United States Environmental Protection Agency (EPA) Brownfields grant funding, data quality can deeply impact grantees’ abilities to achieve their goals for sites undergoing assessment and cleanup. This article will evaluate the total cost of quality in PFAS analyses, emphasizing the strategies necessary to generate the best data for your projects and clients.

The Cost of (Poor) Quality

In his 1956 Harvard Business Review essay “Total Quality Control,” Armand Feigenbaum introduced “The Cost of Quality” concept for industrial manufacturing businesses. The concept introduced four categories of quality-related costs: prevention, appraisal, internal failure, and external failure (Figure 1). Today, the Cost of Quality concept is applicable to PFAS testing, where poor data can lead to costly missteps and far-reaching consequences (Table 1). The costs of poor-quality PFAS data are also often unpredictable, making them impossible to anticipate, schedule, or budget.

Figure 1. Illustration of the four quality cost categories as introduced by Armand Feigenbaum in "The Cost of Quality."

Table 1: The costs of poor-quality PFAS data can be significant and far reaching and are often unpredictable.

If data are determined to be of such poor quality that they are unsuitable for their intended use, additional sampling and analysis may be required to address data gaps. In the most serious of cases, field investigations may need to be completely re-performed, resulting in a loss of previously invested resources, reducing the availability of Cooperative Agreement funds for use on other priority sites, and impacting public trust.

Inaccurate data can also lead to costly and more unnecessary and aggressive approaches for treating and managing PFAS-impacted resources. For instance, if a laboratory produces results that are consistently biased high, it may prompt remedial actions that are more extensive and expensive than required.

Financial penalties for exceeding regulatory thresholds are another potential cost consequence of inaccurate PFAS data. Inaccurate PFAS results can lead to non-compliance with regulatory PFAS standards, which may result in fines and/or enforcement actions.

Beyond financial implications, poor quality data can also impact project timelines, have social and emotional consequences, and damage brand reputations. For brownfield sites undergoing assessment and cleanup with funding provided by EPA Brownfields grants, delayed project timelines can result in projects not being completed before the end of the grant performance period, necessitating the use of funds for grant extension requests that may or may not be approved.

Why PFAS Testing Is So Challenging

PFAS testing involves specialty analytical methods that are particularly difficult to perform accurately for several reasons, including their ubiquitous presence, regulatory requirements, method complexity, and a growing selection of ancillary methods. In particular, the common presence of PFAS in lab equipment, field supplies, and consumer products increases the potential for cross-contamination during both sample collection and analysis. Testing methods demand ultra-low detection limits (often in the parts-per-trillion range), advanced instrumentation, and rigorous controls. Not all labs are up to the task, yet many have rushed to meet surging demand without the experience or infrastructure to deliver reliable results.

Complicating matters further, standard methods only detect a fraction of the estimated 10,000+ PFAS compounds. Newer techniques like Total Oxidizable Precursors Assay (TOPA), Adsorbable Organic Fluorine (AOF), and Extractable Organofluorine (EOF) attempt to estimate total PFAS content, but vary in accuracy, comparability, and validation. Without standardized reporting protocols, reviewing data from different labs becomes both time consuming and error prone.

Building a Foundation of Quality

Investing in high quality data saves money, reduces risk, and improves outcomes. A robust PFAS sampling and testing program aimed at generating high-quality data involves two core strategies: prevention and assessment.

Prevention Strategies:

• Define Objectives Early: Align project teams, regulators, and labs on compounds of concern, detection limits, and intended data use.
• Use Qualified Labs: Vet your proposed laboratories carefully for PFAS-specific experience. Avoid selecting based on lowest price alone.
• Develop a detailed Site-Specific Quality Assurance Project Plan (QAPP): The QAPP should address PFAS-specific requirements and outline Data Quality Objectives.
• Train Sampling Teams: Use PFAS-free materials and emphasize the importance of documentation and adherence to protocols.
• Implement a Quality Management System: Oversee and maintain data quality throughout any sampling and analysis program, evaluating for areas of improvement and ensuring data integrity.
• Include Quality Control Samples: Standard reference materials and blind quality control samples help track laboratory performance and catch anomalies early.

Assessment Strategies:

• Field Oversight: Document and review field practices to ensure adherence to protocols.
• Laboratory Oversight: Review laboratory protocols and practices to monitor performance.
• Data Review: Perform independent data validation and usability assessments throughout the project to evaluate data reliability. Incorporate reviews of comprehensive data packages including all supporting documentation and raw data (known as a Level 4 data report). This review will ensure that data used for project decisions are accurate, complete, and defensible.

For Brownfield Sites, Data Quality Is Non-Negotiable

Brownfield sites often have complex histories and liability considerations. Introducing unreliable PFAS data to brownfield site assessment and cleanup projects can lead to financial, legal, and environmental consequences for environmental professionals, grantees, municipalities, and the public. However, investing in high-quality data can simplify decision-making, reduce risks, and improve project outcomes.

While rigorous testing and oversight may increase upfront costs, those expenses are far less than the cost of poor-quality data. As the demand for PFAS testing grows and regulatory standards evolve, robust approaches to data quality will be increasingly necessary.

For brownfield sites with limited time and funding for assessment and cleanup, high-quality PFAS data are invaluable, enabling informed decisions, improving stakeholder confidence, and helping maximize the use of grant funds. Investing in prevention and rigorous quality assessment from day one is the surest way to protect people, budgets, and reputations.

(A longer version of this article was originally published in the June 2025 issue of the Journal of the New England Water Works Association, Inc.)

The Authors:

by James P. Cinelli, P.E., P.G., BCEE, Liberty Environmental

Vapor intrusion is a growing concern in environmental health, specifically in highly developed urban areas where soil gases or contaminated groundwater can migrate into buildings. Vapor intrusion occurs when volatile organic compounds (VOCs) and other harmful contaminants seep through cracks or other openings in a building’s foundation and it can potentially pose significant health risks to occupants. To combat this issue, Sub-Slab Depressurization Systems (SSDS) have emerged as an effective solution.

Understanding Vapor Intrusion

Vapor intrusion occurs when hazardous vapors from contaminated groundwater or soil migrate into indoor spaces. This typically takes place through small cracks and other openings in the foundation of a building. There are significant health risks posed to occupants of a building who experience long-term exposure to these contaminants ranging from respiratory issues to more severe conditions, including cancer.

What are Sub-Slab Depressurization Systems?

Sub-Slab Depressurization Systems are an engineered solution designed to reduce indoor vapor concentrations. These systems create a vacuum beneath a building’s foundation, drawing vapors away from the sub-slab area and preventing their entry into the indoor environment. The primary components of an SSDS (Sub-Slab Depressurization System) include:

1. Suction Points: These are pits or perforated pipes installed beneath a building’s slab foundation that collect vapors.

2. A Fan: Air circulation from a fan or blower creates negative pressure (depressurization) beneath a slab foundation.

3. Vent Stack: This directs collected vapors beneath a foundation safely outside and away from windows and air intakes to ensure they do not re-enter a building.

Implementation Process

The implementation of an SSDS begins with a thorough site assessment to identify the source and concentration of contaminants. Engineers can then design a tailored SSDS system to address specific building and site conditions. Once designed, installation typically brings minimal disruption, as it can often be completed without significant alterations to an existing structure.

After installation, an SSDS system does require regular monitoring and maintenance to ensure its effectiveness. This includes inspecting suction points for blockages, checking the fan for operation, and conducting air quality tests to verify that vapor concentrations remain at safe levels.

Liberty Environmental’s talented team of remediation experts has proven experience addressing vapor intrusion and assisting in the process of integrating sub-slab depressurization systems. Contact us at info@libertyenviro.com to schedule a site assessment or speak with a member of our team to learn more.  

The Author:

James P. Cinelli is an environmental engineer and the president of Liberty Environmental, Inc., an environmental consulting firm which he co-founded in 2004. The company has 35 employees with offices in Philadelphia, Lancaster, PA, Reading, PA, New York City, and Lebanon, NJ. The company’s clients include local, regional and international companies, and include banks, real estate developers, oil & gas companies, and large manufacturing firms.

by Vincent Carbone, Senior Geologist, HDR, Inc.

Over the years, the redevelopment of brownfields has matured. In fact, in some cases the process of acquiring funding, characterizing sites, remediating and finally redeveloping them has become somewhat routine.  For those fortunate enough to have received funding from federal or state agencies and through economic incentives, redevelopment has been a success.  In most cases, these communities had the ability and organization to assist them in the planning, development, and rehabilitation of properties.  With the assistance of economic development corporations and supportive communities willing to develop their most pressing redevelopment needs, the properties were easy to prioritize and redevelop.  

Now more than ever the need is fixed on those communities that do not have the means or the expertise to manage a portfolio of smaller properties impacting a community.  Perhaps the issue is a highway corridor providing entrance into a key demographic or community.  Perhaps it is an old commercial strip mall that fronts an old industrial complex. For certain it’s not the 1,500 acres of Bethlehem Steel or any one of that prime brownfield’s redevelopment successes, but rather a project with a diverse demographic with little or no vision as how to go about redevelopment from an economic, environmental, or power perspective.  

The Need for a Playbook

It’s time to move to another level of maturity, to make brownfield redevelopment accessible to this less equipped type of community.  But they need help. They need vision. They need a Brownfields Redevelopment Playbook, which provides a holistic summary of the three key factors that make for successful property community redevelopment: Economics, Power/ Infrastructure, and Environmental Stewardship.  This is the first step to helping communities with limited resources prioritize their diverse and unique blend of many properties into a workable vision and plan.  

Economics

Economics is the lifeblood of community redevelopment, but what types of business are appropriate for the community? Will the community demographics be better suited for one industry or another?  What are the current and future economic trends for the locality or region?  What investments should be made to support those trends?  The playbook should provide a framework of the economic drivers for the community and provide both short-term, mid and long-term goals for revitalization to meet those needs.      What industry “fits” with the community that will bring benefits and job creation to the locality and region.  

Power and Infrastructure

With redevelopment comes the need for infrastructure upgrades and efficiency to support new industry or just an aging utility network.  With the development of data centers and battery energy storage facilities, the need for power, water and infrastructure (water, sewer, natural gas, fiberoptics/broadband and power) is immense and poses several questions.  Can the power and utility infrastructure of the community support the proposed redevelopment?  What types of power generation are available for that area?  Is the water supply or wastewater treatment sufficient to address the proposed redevelopment? Can renewable energy supplement in design the more traditional forms of generation?  Short term, mid and long-term needs reflect the economic incentives.  The Playbook can identify infrastructure needs to support proposed economic development and attract business, provide renewable energy resources to the region, and can be integrated with redevelopment on brownfields that have limited options to redevelopment. 

Environmental

Environmental stewardship is the protection of human health and the environment. But it also encompasses the risk and enhancement of natural features such as wetlands or other sensitive habitats.  It also includes a community’s culture and providing enough green and recreational space for the community to enjoy the redevelopment and to enhance the life of occupants of the area.  Together with the economics section, the playbook can identify federal and state brownfields or economic development funds that can be pursued to make the vision a reality.  The playbook should also feature timelines for redevelopment, which can help set realistic goals and demonstrate phased approaches to redevelopment and community engagement.    

Comprehensive and Considerate

Looking at each of the elements individually – economics, power/infrastructure, and environmental—and holistically, playbooks can provide a Highest and Best Use (HABU) or what is considered the best fit for the community.  The Playbook can be used to support grant funding, community outreach, help plan for infrastructure upgrades and goes a long way toward demonstrating a comprehensive and considerate evaluation of improvement in brownfield redevelopment.  

The Author:

Vincent “Vinny” Carbone is a Professional Associate and Senior Geologist with HDR Engineering.  Vinny has been performing brownfields redevelopment services for over 33 years.  During his career he has brought his redevelopment experience to multiple market sectors including transportation, water, architecture, and power redevelopment. Working in HDR’s Bethlehem PA office, he has been redeveloping Bethlehem Steel, and the Lehigh Valley for over 25 years.  He currently is working on several playbooks supporting redevelopment of former coal power plants and former nuclear facilities including several industrial properties across the country.  He is experienced in property redevelopment with USEPA Brownfields grants and is and has been a Qualified Environmental Professional for several Cleanup Grants and Revolving Loan Funds.

by Liberty Environmental

Redeveloping former industrial sites for residential use requires careful evaluation of vapor intrusion risks. There is a risk that volatile organic compounds (VOCs) were released into the subsurface at sites where dry cleaners were located, gas stations were operating, or where other industrial activity previously occurred. These prior uses pose significant potential health risks to future residents. Additionally, properties adjacent to sites that were once gas stations or utilized for industrial purposes may be impacted by migration of vapors from these sources, necessitating a thorough investigation before redevelopment.

What is Vapor Intrusion & How Can it Be Detected?

Vapor intrusion occurs when VOCs migrate from contaminated soil or groundwater into indoor air spaces. This pathway can expose residents to harmful chemicals, making it critical for redevelopers to perform due diligence. A comprehensive environmental site assessment should be conducted prior to any redevelopment to identify potential sources of contamination, including investigation into historical land use and neighboring properties with known releases. When a vapor intrusion risk is identified, sampling and analysis of soil gas and indoor air is performed to confirm the presence or absence of a vapor intrusion condition.

How Is Vapor Intrusion Mitigated?

If vapor intrusion is suspected, a detailed evaluation plan should be implemented. This includes soil gas sampling and indoor air testing to assess the extent of vapor migration. Based on the findings, appropriate mitigation strategies must be incorporated into the redevelopment design. These may include vapor barriers, sub-slab depressurization systems, and enhanced ventilation to prevent VOCs from entering living spaces.

State regulatory agencies provide guidance and oversight for vapor intrusion assessments and mitigation. Engaging environmental professionals and coordinating with state agencies ensures compliance and protects public health.

Why is Addressing Vapor Intrusion Important?

Addressing vapor intrusion is a vital component of residential redevelopment on or near former industrial sites. Proactive evaluation and mitigation not only safeguard future occupants but also facilitate successful and sustainable redevelopment projects.

Liberty Environmental’s talented team of professional engineers, geologists and licensed remediation professionals have proven experience testing for VOCs and implementing remediation for redevelopment projects. Contact us at info@libertyenviro.com to schedule a site assessment or speak with a member of our team to learn more.