This educational webinar explores how critical pressure informs the definition and refinement of a carbon sequestration project’s Area of Review (AoR) under the Class VI permitting framework. The SCS experts explain why some developers are re-evaluating AoR assumptions, how injection-driven pressure propagation can dominate AoR extent, and why project-specific geology (including fluid salinity and basin structure) can make simplified approaches overly conservative, rather than safer.
In this 17-minute session, we compare calculation approaches (Methods 2, 2A, and 3) and emphasize that early, iterative AoR work can reduce regulatory, cost, and public-trust risks.
AoR must account for both plume extent and pressure effects: Beyond the supercritical CO2 plume, pressurization and project critical pressure determine where fluids could migrate upward through improperly plugged/abandoned wells and potentially endanger underground sources of drinking water (USDWs).
Pressure front propagation is often the controlling factor: Pressure can propagate faster and farther than the mobile plume, and may be altered by geologic structures (e.g., faults).
Fluid salinity and density matter: Higher salinity increases fluid density and generally requires more induced pressure to drive vertical migration; real-world salinity profiles can be non-linear and project-specific.
Method selection depends on data and realism: Method 2 is simple but can yield unrealistic outcomes (e.g., zero/negative critical pressure). Method 2A uses a more detailed equation-of-state approach. Method 3 incorporates risk-based computational modeling of flow through a hypothetical, poorly-plugged well and can better handle complex cases.
Timing and iteration reduce downstream costs: Investing early and periodically re-evaluating AOR assumptions improves defensibility and can avoid costly changes after permitting.
Transparency supports outreach: The AoR process and re-evaluations (including public comment opportunities) can be communicated in plain language to build public confidence in drinking water protection.
SCS is delighted to announce that Tom Mesk, CHMM, will join Justin Rauzon as an SCS Engineers National Expert on Environmental Due Diligence. At SCS, National Experts are recognized professionals with industry-leading expertise in specialized environmental sectors.
In his new role, Tom will work alongside Justin to drive innovation, develop training programs, improve efficiency, and serve as a key resource for the SCS due diligence practitioners who routinely solve complex environmental challenges for our clients. Tom has over three decades of experience in environmental risk evaluation and assessment services at sites across the United States. He has technical and management experience with soil, soil vapor, groundwater, surface water, and indoor air investigations at industrial, commercial, landfill, greenfield, and multi-family residential properties. He is similarly experienced with the assessment, remediation, and/or management of common environmental building hazards, such as asbestos, lead-based paint, radon gas, mold, and polychlorinated biphenyls.
Tom is based in SCS’s multi-disciplinary Asheville, North Carolina office, where he routinely conducts environmental assessments and compliance audits at sites across the United States while providing quality control reviews of various technical documents.
With guidance from our National Experts, SCS teams ensure compliance with national, state, and local environmental regulations. SCS solutions also promote sustainability while maintaining operational efficiency and can minimize potential ecological risks.
Additional Due Diligence Resources
Join SCS Engineers at the Environment, Labor & Safety+ Conference (ELS+), taking place April 20–22, 2026, in Houston, TX. This event brings together safety, environmental, and HR professionals across the meat and poultry industry for three days of practical learning, collaboration, and innovation.
ELS+ focuses on the topics that matter most, workplace safety best practices, environmental sustainability initiatives, and labor relations and HR compliance, delivered through insightful sessions and peer-to-peer discussions. Attendees will gain actionable tools and real-world strategies to navigate evolving challenges, strengthen compliance efforts, and support safer, more efficient operations.
Designed for professionals balancing complex responsibilities, Environment, Labor, Safety+ Conference provides a unique space to openly exchange ideas, learn what’s working across the industry, and build meaningful connections with peers and experts.
Be sure to connect with SCS Engineers to learn how we partner with clients to deliver environmental and infrastructure solutions that support safe, compliant, and sustainable operations. Register now.
Oregon’s Department of Environmental Quality (ODEQ) has accredited SCS Engineers’ lead verifiers with the electricity power entity specialty under the ODEQ Clean Fuels Program (CFP). The CFP is a regulatory cap-and-trade system designed to reduce greenhouse gas emissions from fossil fuels.
SCS is now accredited to perform EPE (electricity power entity) transaction verifications for businesses and utilities that are required to report under the CFP. The main type of project under the program is electric charging stations.
The ODEQ requires Electricity Power Entities to submit quarterly reports in the Oregon Fuel Reporting System (OFRS) to verify electricity transactions. SCS, as an accredited third-party verification body, ensures data quality and accuracy, with specific verification statements required for electricity suppliers. Clients receive a full verification report including; information on facility boundaries and data sources, a description of accounting procedures and data management, a copy of the verification plan, a description of the data checks the verification body conducted, a log of issues, any qualifying comments the verification body would make about its findings during the verification process, and a copy of the verification report and statement.
SCS GHG verification scope includes entity-wide disclosures, single facilities, public and private electricity generation facilities, compliance offsets, and renewable fuel pathways. SCS Engineers also conducts independent audits of environmental data, including electricity and water usage, waste, and energy use, to support accuracy, compliance, and efficiency across all operations.
In addition, as an Accredited CFP Verification Body in Oregon, SCS Engineers verifies the following programs:
If you’d like to learn more about these programs or cap-and-trade, please get in touch with our GHG experts at SCS Engineers.
Additional Resources:
The actual text of EPA’s final rule rescinding the 2009 Endangerment Finding was published this morning. Several other documents in support of the final rule also were posted on the EPA website: Final Rule: Rescission of the Greenhouse Gas Endangerment Finding and Motor Vehicle Greenhouse Gas Emission Standards Under the Clean Air Act | US EPA
Most of the rule’s immediate effects will be on motor vehicles. The regulations directly affected are 40 CFR Parts 85 (Control of Air Pollution from Mobile Sources), 86 (Control of Emissions from New and In-Use Highway Vehicles and Engines), 600 (Fuel Economy and Greenhouse Gas Exhaust Emissions of Motor Vehicles), 1036 (Control of Emissions from New and In-Use Heavy-Duty Highway Engines), 1037 (Control of Emissions from New Heavy-Duty Motor Vehicles, and 1039 (Control of Emissions from New and In-Use Nonroad Compression-Ignition Engines)
The final rule does not affect criteria pollutant emission standards, mobile-source air toxics standards, or vehicle fuel-economy standards (also known as Corporate Average Fuel Economy, or CAFE, standards).
How will the rescission of the Endangerment Finding affect the solid waste industry? To the extent that heavy-duty trucks and equipment become less expensive with no requirements to limit GHG emissions, solid waste companies will see savings. However, major CAA regulatory programs such as New Source Performance Standards for landfills and operating permits for landfill gas control systems are unlikely to be affected, at least in part, because, at the federal level, the threshold triggers for these programs are based on non-methane organic compounds rather than greenhouse gas emissions.
It remains to be seen if EPA will follow through on changes to the Mandatory Greenhouse Gas Reporting Program under 40 CFR Part 98 as proposed last September. Among those changes would be to eliminate GHG reporting for 46 industrial categories, including municipal solid waste landfills and industrial waste landfills. Some of those affected have asked the EPA to continue requiring GHG reporting because they do not want to be subject to numerous state reporting programs, including New York’s new program that takes effect in 2027, as well as California, Oregon, and Washington, which already have GHG reporting. Some states that require GHG reporting directly reference 40 CFR Part 98 and/or rely on the EPA’s electronic Greenhouse Gas Reporting Tool (eGGRT).
Another aspect of the rescission of the Endangerment Finding is any effect that may have on any preemption of state laws outside the motor vehicle context. Several states are not waiting for the EPA in this regard, requiring GHG reporting and disclosures as a matter of state law.
The recission final rule is based on the EPA’s interpretation of the Clean Air Act as a legal matter. Although EPA “continues to harbor concerns regarding the scientific analysis contained in the Endangerment Finding . . . . the Administrator is not basing this action on a new finding under CAA section 202(a)(1). Rather, we conclude that the EPA lacks statutory authority to resolve these questions under CAA section 202(a)(1).” Section 202(a)(1) covers emission standards for new motor vehicles or new motor vehicle engines.
Boiled down to its essence, EPA is saying that it never had the legal authority from Congress to regulate GHGs under the Clean Air Act. It says that the CAA addressed air pollution having local and regional impacts, not pollution that may affect global climate change. By taking this approach, the EPA avoids addressing climate science altogether.
Under the Supreme Court’s “major questions” doctrine, President Obama couldn’t regulate greenhouse gas emissions outside the fence line as part of the Clean Power Plan in the electric utilities sector. President Biden couldn’t require COVID-19 vaccinations or forgive student loans en masse. President Trump might not have been able to impose tariffs under the International Emergency Economic Powers Act because such major questions require specific congressional authorization. EPA cites the major questions doctrine as requiring rescission of the 2009 Endangerment Finding.
The goal appears to be to secure the Supreme Court’s affirmation of the EPA’s current views before Mr. Trump leaves office. The Court has considered aspects of EPA’s GHG regulations from time to time since the 2009 Endangerment Finding was published. Of course, the Court said that EPA could prepare an Endangerment Finding, but it never directly considered the finding itself. If the Court ultimately rules that the CAA does not authorize the EPA to regulate GHGs, one assumes that, until Congress passes a new law addressing GHGs, there will be no such regulation at the federal level.
If you have questions about federal, state, or local air quality regulations, reporting, or verification, please contact the experts at SCS Engineers.
SCS Engineers is proud to participate in Lucky Leaf Expo Minneapolis! Taking place February 27–28, 2026, at the Minneapolis Convention Center. As Minnesota emerges as one of the nation’s next major cannabis markets, this two-day conference brings together industry professionals, regulators, entrepreneurs, and job seekers to explore opportunities shaping the future of cannabis in the region. SCS Engineers partners with clients to address environmental compliance, odor control, zoning, and infrastructure planning challenges critical to sustainable cannabis operations. Register today!
Visit Booth #125 to connect with Eva Luu, Sonya Betker, Armando Hurtado-Garcia, and Christopher Petro, and attend the following SCS Engineers-led sessions:
Cannabis Without the Complaints: Zoning, Odor Control, and Sustainable Industry Growth
Presented by Christopher Petro and Armando Hurtado-Garcia
This session explores how cities can balance economic growth with community impacts through effective zoning, odor control standards, permitting strategies, and operational best practices that support long-term industry success.
Making Scents of Odor Control: Evaluating Mitigation Technologies and Trade-offs
Presented by Eva Luu and Armando Hurtado-Garcia
Drawing on years of field testing, this presentation compares odor control technologies by evaluating environmental conditions, maintenance needs, cost-effectiveness, and public perception to help decision-makers select the right solutions for specific operational scenarios.
As an employee-owned environmental consulting and construction firm, SCS Engineers supports the communities we live and work in year-round. But we all want to be doing something extra during the holidays.
In 2024, SCS donated to 43 local registered IRS 501(c)(3) charities during the holidays, positively impacting over 90,000 people! Our Corporate program has proven to be successful, so we plan to grow it this year.
In addition to supporting this year’s annual SCS Young Professional Group’s holiday fundraising, we plan to send significant donations to the four charities below that align with the environmental nature of our business and do so much for others. We will continue funding the Robert Stearns SWANA and the Environmental Research & Education Fund Scholarships.
These charities rely on consistent donations from patrons like SCS and you. We thank them all for their continuing humanitarian work. As always, we will continue to donate year round to the Red Cross and World Central Kitchen in support of people impacted by natural disasters worldwide.
Join SCS Engineers and John Tsun as he serves as one of the co-organizers for the 24th Annual Joint Venture NJDEP/Air & Waste Management Association (A&WMA) Regulatory Update Conference, November 21st.
This one-day virtual event provides attendees with the latest updates on New Jersey Department of Environmental Protection (NJDEP) regulatory initiatives and programs related to environmental compliance, air quality, contaminated site remediation and redevelopment, energy, materials sustainability, water quality, and climate change mitigation.
The conference offers a valuable opportunity for environmental professionals, regulators, and industry leaders to engage directly with NJDEP representatives and stay informed on emerging policies, research, and best practices shaping the future of sustainable environmental management. Register now.
The U.S. Environmental Protection Agency’s (EPA) Office of Land and Emergency Management (OLEM) announces it is updating guidance for addressing residential lead exposures at Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and Resource Conservation and Recovery Act (RCRA) sites.
The new directive for investigating and cleaning up lead in residential soil at contaminated sites emphasizes early collaboration with state and local partners to protect communities. You should consider this as a directive for all sites with residential lead contamination subject to CERCLA response and RCRA authorities, including federal facility cleanup programs subject to CERCLA Section 120, and potentially by federal agencies using response action authorities delegated to them under Executive Order 12580.
This Directive supersedes the January 2024 Updated Residential Soil Lead Guidance for CERCLA Sites and RCRA Corrective Action Facilities in addressing lead contaminated soil on residential properties at CERCLA and RCRA sites.
The agency’s new guidance aims to address inefficiencies which slow progress to decrease lead exposure in residential neighborhoods at Superfund and hazardous waste sites. The updated directive establishes the following:
EPA will continue to use site-specific factors, including exposure considerations, soil lead background levels and community input, to make informed decisions on how to address lead exposure at each site.
The announcement on October 20, 2025, also includes a series of process improvements to accelerate response actions that address lead contaminated soil on residential properties including more nationally consistent cleanup decisions, early engagement with state and local partners, sharing best practices through the establishment of a National Center of Excellence for Residential Lead Cleanups, and specialized contracting mechanisms to leverage removal and remedial actions.
EPA plans for a roadmap for response action decision-making at residential properties and other high impact areas for children (e.g., schools, playgrounds). EPA defines residential properties as any area with high or unrestricted accessibility to sensitive populations (e.g., young children less than 7 years old) and includes, but is not limited to, properties containing single- and multifamily dwellings, apartment complexes, vacant lots in residential areas, schools, daycare centers, community centers, playgrounds, parks and other recreational areas, green ways, and any other areas where young children may risk exposure to site-related contaminated media. The roadmap will include engineered and non-engineered approaches.
Establish a National Center of Excellence for CERCLA Residential Lead Cleanups as a centralized resource to share expertise across regions, identify and facilitate efficiencies, and establish best management practices across all phases of characterization and cleanup.
CERCLA five-year reviews (FYRs) remain an essential statutory tool to evaluate protectiveness of both engineered and non-engineered remedy components at any site where hazardous substances, pollutants or contaminants remain on site above levels that permit unlimited use and unrestricted exposure, per CERCLA Section 121(c) and 40 CFR Part 300.430(f)(4)(ii). The findings of a FYR may result in the need for further evaluation, cleanup and/or institutional controls to support short- and/or long-term protection.
Additional Resources:
Congratulations to Gabrielle Stephens for her promotion to lead SCS’s Southwestern U.S. Air Compliance Group. She brings over two decades of client success to the role.
Greenhouse gas (GHG) reporting or verification, regulatory air compliance, and air permitting services fall within Ms. Stephens’ purview. She leads teams that support clients in the solid waste and manufacturing industries, who find value in having a regulatory liaison to navigate ever-changing federal, state, and local regulations. These teams help maintain efficient operations and enhance business communication with stakeholders.
Regulatory agencies often operate independently, and knowledgeable environmental consultants know how best to meet multiple agency data requirements, resulting in positive relationships between agencies and clients. SCS clients find that improved communication helps minimize or prevent permitting and compliance delays. Agencies, especially air district staff, can depend on the accuracy of Clean Air Act experts who are experienced with newer technologies proven to work, but potentially new in a district.
Ms. Stephens’ experience spans multiple states, numerous air districts and local enforcement agencies.
Beyond her work in air permitting and compliance, Ms. Stephens works on emissions estimates and inventories and has extensive experience preparing permit-to-construct/operate and Title V permit applications. She has also undertaken projects evaluating and reporting to meet the federal Greenhouse Gas (GHG) Rule and the AB 32 Landfill Methane Rule. Her collaborative efforts with the solid waste industry contribute to multiple facilities obtaining landfill gas-to-energy and RNG permits that positively impact air quality.
Ms. Stephens’ air compliance audits, permitting, and compliance reporting for manufacturing facilities, including fiberglass boats, product removers, ceramics, paper products, and cement/aggregates, help ensure regulatory compliance and improve operational efficiency.
Additional Clean Air Act Resources:
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