How Citadel EHS Secured Rare NFA Letters for VOC Sites in California: A Practical Path to Closure11/24/2025
Brownfield Braintrust Podcast
California regulators have dramatically reduced the number of No Further Action letters issued for contaminated properties over the past several years. Closures for sites impacted by chlorinated solvents such as PCE, TCE, and benzene have become increasingly difficult, especially under the updated 2023 CalEPA vapor intrusion guidance. In this new episode of the Brownfield Braintrust podcast, Matt Winefield talks with Greg McIver of Citadel EHS, one of the few consultants in California that has successfully obtained No Further Action letters for VOC sites in 2024 and 2025. Their discussion provides rare insight into what still works, what regulators expect, and how a property can realistically move toward closure today. This blog post summarizes the key lessons and case studies from their conversation and includes the embedded episode so readers can listen in full.
Why California Closures Have Declined
Winefield & Associates reviewed statewide NFA data earlier this year and found a 50 percent reduction in closures between 2017 and 2023. Vapor intrusion concerns, expanded screening requirements, and stricter risk evaluations have contributed to this decline. Regulators now require more data, more lines of evidence, and more certainty before approving closure, which prolongs investigation/remediation timelines and increases costs. Many owners and brokers underestimate the effort required to reach closure under today’s rules. This episode explains how closure is still possible when the process is managed strategically from the start. Who Citadel EHS Is and Why Their Success Matters Citadel EHS is a leading environmental consulting firm in California with expertise in vapor intrusion, chlorinated solvent remediation, toxicology, sub slab depressurization, and remedial design. Greg McIver, Principal Scientist and Co Practice Lead, brings 25 years of experience managing complex VOC sites. Citadel received multiple No Further Action letters for VOC impacted properties in 2024 and 2025. These recent closures provide a practical roadmap for others navigating the same challenges. The Most Important Factor: Stakeholder Buy In Greg explains that successful closures start with coordinated involvement from: • The regulatory agency • The environmental consultant • The property owner or developer • The legal and technical team when needed Instead of working in isolation and submitting reports at the end, Citadel collaborates closely with regulators from the outset. They confirm data gaps, agree on next steps, and shape the conceptual site model with the case manager involved. This approach reduces surprises and builds a shared understanding of the path to closure. Using the Low Threat Closure Framework for Solvent Sites Citadel uses the San Francisco Bay Regional Water Board’s 2009 Low Threat Closure Criteria for chlorinated solvents as an internal guide. Even when a regional board does not formally adopt this guidance, the structure helps consultants prepare a logical, evidence-based closure argument. Key criteria include: • Source removal • Delineation of soil vapor and groundwater impacts • Evaluation of sewer pathways • Demonstration of long-term protectiveness • Assurance that groundwater concentrations will reach water quality objectives • Documentation of multiple lines of evidence for vapor intrusion This consistent framework is one of the strongest tools for navigating closure under today’s standards. Case Study 1: Dry Cleaner Site in San Mateo County Citadel obtained a No Further Action letter for this site in October 2025. The property had legacy PCE releases from a former dry cleaning operation. Key achievements include: • Groundwater PCE concentrations decreased to 32.9 micrograms per liter • Soil vapor concentrations decreased from 1950 to 612 micrograms per cubic meter • Indoor air remained below commercial screening levels • Contaminated soil and sewer line impacts were excavated • Zero valent iron was injected to accelerate attenuation • No post NFA long term indoor air monitoring was required • A commercial use land use covenant was recorded This case demonstrated that closure is possible even with soil vapor concentrations above screening values, provided indoor air risk is sufficiently controlled. Case Study 2: Central Valley Dry Cleaner with High VOC Impacts A second No Further Action letter was issued by the Central Valley Regional Water Board in October 2025. This property had two former dry cleaners and much higher chlorinated solvent concentrations than Case Study 1. Key results: • Historical groundwater PCE reached 8,000 micrograms per liter • The highest well PCE concentration at closure measured 88.3 micrograms per liter • All other wells were below the 5 micrograms per liter drinking water standard • Soil vapor dropped from 900,000 to 1.77 micrograms per cubic meter • Vapor extraction, injections, and groundwater treatment had been used previously • Citadel shut down treatment systems that were no longer effective • Multiple lines of evidence supported continued natural attenuation • Post closure groundwater trending was the only requirement This case shows how strategic reassessment and focused sampling can replace years of unnecessary treatment system operations. What These Closures Tell Us About Costs Many brokers and property owners assume a dry cleaner cleanup costs in the neighborhood of $100,000 (“Just dig it out of there.”). The real numbers are far more daunting. VOC sites regularly require: • Several hundred thousand dollars when limited excavation or injections are enough • More than one million dollars when vapor extraction or groundwater treatment is involved • Higher budgets when two or more operators contributed to a comingled release Accurate cost modeling helps reduce uncertainty during brownfield transactions. Citadel uses expected, optimistic, and pessimistic cost scenarios to help clients make informed decisions. Major Lessons from Citadel’s Closure Strategy The episode highlights several takeaways for anyone evaluating or remediating VOC sites: • Collaborative regulators make closure achievable when engaged early • A complete conceptual site model prevents expensive surprises • The low threat closure framework remains one of the best planning tools • Treatment systems should be shut down when they no longer remove mass • Multiple lines of evidence are essential for demonstrating protectiveness • Thorough groundwater data reduces risk premiums for buyers and sellers • Closure is possible even with residual VOCs when indoor air is safe These lessons reflect what is working now across California. Listen to the Full Conversation The full discussion between Matt Winefield and Greg McIver offers detailed explanations, regulatory insights, and a rare look at recent NFA letters for VOC impacted sites. About Citadel EHS Citadel EHS is a market-leading environmental consulting firm specializing in vapor intrusion, toxicology, site assessment, remedial design, and environmental health and safety solutions. Greg McIver Principal Scientist & Practice Leader, Engineering & Environmental Sciences Email: [email protected] Website: https://citadelehs.com LinkedIn: Greg McIver
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In this Brownfield Braintrust Podcast episode, our very own Matt Winefield, along with Steve Figgins of EKI Environment & Water, Inc. and Mark Johnson of Offit Kurman, discuss transforming oil production fields and how their remediation may differ from other industrial sites. For oil production think of wells, open fields, collection tanks, production pumps, and oil collection ponds. This topic is of particular interest as the State of California has not been shy about its intent to shut down oil production across the state. What may become a loss for oil production could be a gain for remediation companies, home builders, and commercial developers.
In this Brownfield Braintrust Podcast episode, we discuss environmental vapor sampling with two exceptional experts in the field, Will Rice of Enthalpy Analytical and Kevin Kelly of Langan Engineering. Those of you who are actively involved in brownfields assessment, remediation, and redevelopment have had to come to terms with new vapor intrusion agency guidelines and regulations that have tightened environmental screening. The reduced screening levels have prompted us to analyze more soil and soil vapor samples, so there is a greater need than ever to be efficient in the field and in the laboratory. To that end, we are going to examine one patented solution, VaporDeck™, a tool for soil vapor sampling everywhere. The VaporDeck™ provides a better solution to allow sample crews to simultaneously pull 2 or more samples from different depths, collect actual duplicates, and move from location to location faster, all while maintaining sample integrity and field documentation.
Our two esteemed guests:
The CalEPA State Water Resources Control Board is Issuing Very Few No Further Action Letters!5/2/2024
This podcast episode is a companion discussion for the W&A February 26, 2024, Vapor Intrusion blog, which you can access here: https://www.winefieldinc.com/vi-blog/calepa-swrcb-site-closure-rates-continue-to-decline-likely-due-to-vapor-intrusion-guidance
Matt Winefield discusses the Winefield & Associates GeoTracker data review of No Further Action (NFA) letter issuance rates before and after the CalEPA Vapor Intrusion Guidance (VIG) was promulgated. The data is not pretty. There no longer appears to be a path to closure for remediation projects of sites impacted with volatile organic compounds. Absent the ability to eventually achieve an NFA, brownfield investments throughout California are precarious. Visit Winefield & Associates, Inc. at: https://www.winefieldinc.com/ Find Matt Winefield on LinkedIn at: https://www.linkedin.com/in/mattwinefield/ Calling all commercial and industrial brokers! Matt Winefield had the privilege of taking part in a virtual Q&A session with eXp Commercial. eXp industrial brokers peppered Matt with questions about how to get deals closed when faced with contaminated soil and groundwater. This podcast includes a 15-minute overview of strategies for divesting brownfield properties and transferring environmental liabilities. The remaining 40 minutes are filled with real world solutions to actual transactions in the brokers’ portfolios. We have provided time stamps below the video podcast so you can peruse subjects of interest: Time Stamp - Topic
2:20 - eXp Introduces Matt Winefield 5:30 - Presentation Begins – “Saving a Property Transaction with Recognized Environmental Conditions” 6:00 - Defining a Phase I Environmental Site Assessment 7:44 - Types of Contaminated Properties 8:30 - Typical Remediation Methods 10:00 - General Thoughts on Environmental Price Reductions 13:40 - Third-Party Sources of Environmental Funding 15:00 - Expected Investor Returns for Brownfields 16:00 - Success Story No. 1 – Industrial Cleaner/Launder 17:00 - Success Story No. 2 – Gas Station 18:55 - Pre-Screening Sites for Environmental Problems 20:15 - Conventional Debt Availability for Contaminated Sites 23:25 - Environmental Disaster Story No. 1 – Dry Cleaner 25:00 - Environmental Insurance Polices 26:00 - Environmental Due Diligence Periods 30:40 - Environmental Disaster Story No. 2 – Plating Shop 31:20 - Environmental Grant Resources 33:20 - Older General Liability Insurance Policies and Possible Environmental Coverage 36:40 - Soil Vapor vs. Soil Matrix Sampling 42:00 - Transparent Approach to Negotiating Environmental Cost Reductions with Sellers 44:30 - Auto Shop Environmental Risks 52:00 - Broker Listing Strategies for Environmentally Impacted Properties It was a privilege for Winefield & Associates to be on a panel during the September California Land Recycling Conference. Our founder, Matt Winefield, shared a stage with environmental attorney Allison Torbitt and affordable housing developer Mary Jane Jagodzinski. The topic was Navigating Brownfields from a Developer’s Lense. Attendees included over 150 developers, regulators, consultants, and attorneys. Our brief presentation starts at about minute 12 and Matt's inquiries to the audience about California No Further Action letters begins during minute 41. Much was discussed about remediation funding and how to address brownfield regulatory challenges from both the non-profit and for-profit perspectives. In our current Brownfield Braintrust Podcast, Matt Winefield of Winefield & Associates, Inc. sheds light on Vapor Intrusion Mitigation Systems (VIMS) with the help of Justin Conaway, Vice President and General Manager of Terra-Petra Environmental Engineering. Given evolving soil vapor mitigation standards, VIMS are currently much more prevalent than just three years ago. It is unlikely one can acquire, for example, a former dry cleaner site (with PCE releases), run a vapor extraction system, and then pour your foundation. The lead agency will likely specify a VIMS that operates for the life of the new building. Justin explains the three most common VIMS technologies now utilized. Visit Terra-Petra at: https://terra-petra.com/
Find Justin Conaway on LinkedIn at: https://www.linkedin.com/in/justinconaway/ Visit Winefield & Associates, Inc. at: https://www.winefieldinc.com/ Find Matt Winefield on LinkedIn at: https://www.linkedin.com/in/mattwinefield/ To listen to an audio-only version of this podcast episode, click here. In this episode of the Brownfield Braintrust Podcast, Matt Winefield switched roles. He was a guest on “Straight Talk Schools,” a commercial real estate YouTube broadcast sponsored by Dusty Bates, broker extraordinaire of EXP Commercial. Dusty interviewed Matt in a discussion that could be entitled either “The Basics of Brownfields Investments” or “How to Save a Commercial Transaction When You Have a Bad Phase I.” For all of those new to sites with contaminated soils and groundwater, here are some guidelines on assessing environmental risks/costs as well as strategies to close your property sale or purchase. Winefield & Associates was delighted to interview Clark Henry, one of the organizers of the EPA ICMA National Brownfields Training Conference, August 8-11, 2023, Detroit, MI. The Brownfields Conference brings together stakeholders from government, industry, and the community to share knowledge and best practices on the remediation and redevelopment of contaminated properties, known as brownfields. The conference features a range of sessions, workshops, and networking events that cover topics such as financing, liability, and community engagement, with the goal of promoting the cleanup and revitalization of contaminated sites across the United States. Register for the National Brownfields Training Conference at: https://brownfields2023.org/
Visit International City/County Management Association at: https://icma.org/ Find Clark Henry on LinkedIn at: https://www.linkedin.com/in/clark-henry-11950630/ In this podcast episode, Matt Winefield interviewed one of the nation’s leaders in Licensed Site Remediation Programs (LSRP), Sue Boyle. LSRPs are used in many states to supplement environmental agency oversight of remediation programs to expedite site assessments, remediation, and closures. Ms. Boyle was kind enough to present with Winefield & Associates at our March 10, 2023, Brownfield Seminar in Santa Monica, CA. Here were some of the highlights:
Find Sue Boyle on LinkedIn at: https://www.linkedin.com/in/sue-boyle-86a255a/ |
