Learn about SCS Engineers Air Emissions Services
Power Plants: 40 CFR Part 60, [EPA-HQ-OAR-2025-0124; FRL-12674-01-OAR], RIN 2060-AW55
On Wednesday, June 11, 2025, the U.S. Environmental Protection Agency (EPA) proposes repealing all greenhouse gas (GHG) emissions standards for fossil fuel-fired power plants. The EPA proposes that the Clean Air Act (CAA) section 111 requires it to find that GHG emissions from fossil fuel-fired power plants contribute significantly to dangerous air pollution as a predicate to regulating GHG emissions from those plants, which the current administration does not agree with.
The EPA is further proposing to make a finding that GHG emissions from fossil fuel-fired power plants do not contribute significantly to dangerous air pollution.
The EPA is also proposing, as an alternative, to repeal a set of requirements that includes the emission guidelines for existing fossil fuel-fired steam generating units, the carbon capture and sequestration/storage (CCS)-based standards for coal-fired steam generating units undertaking a large modification, and the CCS-based standards for new base load stationary combustion turbines.
EPA is proposing to repeal certain amendments issued in 2024 to the National Emission Standards for Hazardous Air Pollutants for Coal- and Oil-Fired Electric Utility Steam Generating Units – a rule commonly known as the Mercury and Air Toxics Standards for power plants, or simply MATS. This proposal would revert to 2012 standards for air toxic pollutants from coal- and oil-fired power plants.
This action proposes to relieve all facilities of the more stringent filterable particulate matter (PM) emission standard for coal-fired EGUs, the tighter mercury standard for lignite-fired EGUs, and the requirement to use PM Continuous Emissions Monitoring Systems (CEMS).
Comment Period
Public and industry comments must be received on or before 45 days following publication in the Federal Register. This document is a prepublication version, signed by EPA Administrator Lee Zeldin on 06/11/2025. While the EPA has taken steps to ensure the accuracy of this version, it is not the official version.
The EPA will hold a virtual public hearing in the future. You may send comments identified by Docket ID No. EPA-HQ-OAR-2025-0124, using these channels as follows:
All submissions received must include the Docket ID No. for this rulemaking. Comments received may be posted without change to https://www.regulations.gov, including any personal information provided.
Please get in touch with SCS Engineers with questions pertaining to your power plant operations or facilities. Thank you. We will post regulatory updates in more detail as they unfold.
SWANA Western Regional Symposium will naturally feature SCSers talking landfills! We hope to see you at these sessions.
L’ is for Landfill Redevelopment – From Golf Courses to Graveyards, Adventures in Landfill Redevelopment with Vidhya Viswanathan and Ray Huff
Landfill redevelopment transforms sites into valuable community assets, such as parks, solar farms, or warehouses, addressing environmental concerns and supporting sustainable land use. This presentation explores the benefits of redevelopment, emphasizing environmental, community, and financial advantages. It also addresses technical, financial, and regulatory obstacles, with strategies for overcoming them through stakeholder collaboration, using case studies to highlight lessons learned.
Landfill Construction for Integrated Gas Systems with William Haley and Evan Guignon
With ever-increasing regulations pushing more and earlier methane capture, including during landfill filling, how can we design and construct our landfill cells to allow the integrated gas collection and gas collection infrastructure to be built alongside our landfill cells? This presentation will cover regulatory requirements for cell construction and gas capture and how landfills can be designed and constructed to allow the gas collection system to work in tandem with the landfill leachate collection system. We will cover several examples of integrated cell/gas collection systems and delivered performance since installation.
Explore the full list of sessions from SCSer’s at the SWANA Western Regional Symposium, we look forward to seeing you! Register today!
Current State of the Regulation of Composting Facilities under Air Quality Programs with Pat Sullivan
Composting facilities are becoming increasingly regulated across the country, particularly for air quality permitting requirements. It is important to know where these requirements stand in the various jurisdictions in the U.S., so facility developers can properly plan any new facilities or expansions. Further, estimating air emissions is an integral part of the air permitting process, and many of the emission factors currently in use, and being prescribed regulatory agencies, are dated and based solely on data from open windrow composting.
The proposed presentation would include a survey of how compost facility air permitting is presently handled in various states and local jurisdictions across the country with focus on the western U.S. The types of information to be covered would include whether air permits are required and under what circumstances, how emissions are regulated and whether they are considered fugitive or not, how ancillary equipment is permitted (e.g., grinders, windrow turners, etc.), whether controls are required and what levels of control are deemed necessary, what is best available control technology (BACT) for composting, and if the agency has any specific rules for composting. The presentation will include a summary of the current state of emission factors for composting.
As part of the presentations, more detailed air permitting information would be supplied for several example air jurisdictions in California, including the Bay Area AQMD and San Joaquin Valley APCD. The examples would cover the range of complexities from the most stringent air permitting requirements to the simplest and most basic requirements.
The attendees to this presentation will learn about:
Can We Get Credit for That? with Victoria Evans and Erik Martig
To reduce GHG emissions to meet climate goals, numerous strategies encourage lowering the carbon intensity of operations and supply chains. Here, Victoria and Erik answer the question of ‘Can we get carbon credit for that?” by addressing offsetting and insetting projects applicable to waste related commodities. They focus upon compost and biochar providing relevant examples for both offsetting and insetting. Insetting involves directly reducing emissions within the company’s own operations and value chain. Victoria and Erik will provide examples of carbon accounting quantification for both project types.
Explore the full list of sessions from SCSer’s at the SWANA Western Regional Symposium, we look forward to seeing you! Register today!
AW&MA’s most popular specialty conferences, the Air Quality Measurement Methods and Technology Conference, is April 23-25, 2025. This conference provides extensive coverage of all aspects of air measurement methodologies, including associated quality assurance protocols and how to use and interpret data. Sessions will also focus on the assessment of key substances of concern for humans and the environment, including criteria pollutants, greenhouse gases, and air toxics.
Jose Landeros and Sergio Valenzuela will be presenting “Empowering Imperial County AB617 North End Communities With Low-Cost Monitoring Sensors.”
The Imperial County Air Pollution Control District (ICAPCD) has become a model for Assembly Bill 617, demonstrating how collaborative efforts in environmental justice can address complex air quality challenges, including pollution from agricultural, industrial, and cross-border sources. This conference is a unique opportunity to engage with local experts and explore solutions across scientific, legal, regulatory, policy, and communication domains, empowering professionals to address pressing environmental justice issues.
Eva Luu and Armando Hurtado will be presenting “Real-Time Monitoring of Odor Using Sulfur as a Surrogate,” during the Agricultural Emissions and Odor Measurements track.
Cannabis remains a contentious topic in the United States. While a majority of Americans support legalization, challenges such as nuisance odors have emerged, complicating the landscape. Geographical location plays a significant role in the success of cannabis cultivation, particularly in outdoor and greenhouse settings, where moderate temperatures benefit crop production. These same favorable weather conditions often align with increased population density, heightening the need for effective odor mitigation strategies. Although the distinctive “skunky” odor has traditionally been linked to terpenes, recent research suggests that other compounds play a critical role.
To address cannabis odors, various mitigation methods have been implemented, including misting systems, carbon filters, and advanced scrubber units using ozone and photocatalytic oxidation (PCO).
Each of these methods can be effective for odor controls in the appropriate settings and when applied to specific cultivation methods.
While these techniques can reduce onsite odors, offsite locations frequently continue to detect the characteristic smell. Odor samples can be collected onsite and analyzed in Odor Labs, but they do not provide real-time data for cultivators to make immediate adjustments to operations.
Through meticulous planning and iterative rounds of testing, we identified total reduced sulfurs (TRS) as a reliable surrogate for real-time measurements of cannabis odors in enclosed spaces. This approach allows operators to identify odor problems in situ and take necessary action in a timely manner. The findings underscore the importance of innovative measurement techniques in improving odor management practices and enhancing the sustainability of cannabis cultivation. This work aims to contribute to a more comprehensive understanding of odor dynamics in cannabis production, ultimately assisting cultivators in effectively addressing community concerns while optimizing operational integrity.
Learn more at SCS Engineers.
Remote monitoring and control (RMC) is revolutionizing how the solid waste industry collects, processes, and visualizes critical data. With a fleet of FAA-licensed drone pilots nationwide, RMC is at the forefront of developing drone services that enhance operational safety, improve efficiency, and optimize data management processes. By leveraging cutting-edge drone technologies and GIS-based data assessment tools, the waste management industry can streamline remote data collection and decision-making processes.
This presentation, Advancing Drone Technologies for the Solid Waste Industry explores how drone technologies are reshaping industry practices, offering solutions that reduce operational costs, minimize environmental impact, lower health and safety risks, and improve overall site efficiency. Attendees will gain insights into the latest advancements in drone applications and learn practical strategies for integrating these technologies into their operations.
Specifically, attendees can expect to learn:
Meet SCSers, Phil Carrillo, National RMC Director/VP and Melissa Russo, Business Manager – Drones & GIS.
Phil is a systems integrator with over 24 years of experience in the operations and maintenance (O&M) of landfill gas (LFG) extraction and treatment systems. Phil has managed the design and installation of over 180 RMC systems for 100 clients. In addition to serving clients with customized design, installation, and support of SCS RMC solutions, Phil is an FAA Part 107 drone pilot and leads the development of advanced drone technologies and custom software applications that enhance data management and operational efficiencies for the solid waste industry.
Melissa Russo leads SCS RMC’s drone services. She is instrumental in managing the administration and installation of approximately 150 RMC projects and as an FAA-licensed drone pilot, she leads the development of SCS’s drone services, identifying the latest applications to benefit clients in optimizing remote data collection, GIS integration, and data management. Melissa has managed and performed numerous aerial inspections nationwide and internationally for purposes such as thermal surveillance, methane leak detection, topographic mapping, stockpile calculations, aerial 2D imagery, and 3D mapping. She is responsible for integrating GIS with drone-collected data to enhance field data collection and analysis, enabling more precise and actionable insights for clients.
Explore the full list of sessions from SCSer’s at the SWANA Western Regional Symposium, we look forward to seeing you! Register today!
EPA updated its Compliance and Emissions Data Reporting Interface (CEDRI) for the electronic reporting of air emissions under the NESHAP related to MSW landfills. Three new reporting templates were added on October 15, 2024, each linked to its corresponding Excel spreadsheet template. These include the
The Semi-Annual report is the most significant because MSW landfills have 90 days to begin using the Excel template. Reports due January 13, 2025, or any time after that must include this electronic filing.
EPA’s color-coded template provides a bit of instruction.
The gray tab (Company Information) contains general information likely to be unchanged from report to report. After completing the gray tab, you may save the workbook as a site-specific template to use in subsequent reports to limit subsequent data entry.
Complete the green tabs (Certification, CMS Info, Description of Changes, Exceedances, and Number of Exceedances) as appropriate to complete the semi-annual report.
Complete the blue tabs (Deviation Detail, Deviation Summary, CMS Detail, and CMS Summary) if deviations or CMS out-of-control periods or downtime periods occur according to §63.10(e) and as defined in §63.1990.
The orange tabs (Well Expansion, Operational Statements, Site Specific Treatment, Enhanced Monitoring, Bypass CDT Not Operating, and Corrective Action Analysis) cover information required by the semi-annual report requirements of §63.1981(h); be sure to complete the requisite tabs.
Professionals at SCS Engineers will post more guidance but plan to continue preparing our clients’ semi-annual reports as we do now, and completing and submitting this spreadsheet. Please work with your air emissions specialist or project manager, or contact us for support.
Additional Resources:
Join SCS for an unforgettable experience as we delve into the solid waste industry’s latest trends, technologies, and best practices. Network with industry experts, discover innovative solutions and gain valuable insights to enhance your professional growth.
We’re excited to have you here and look forward to a successful and inspiring conference. Join SCS’s Jeff Leadford, PE, for his session covering “Landfill Odor Analysis With Monitored Data.” Jeff puts his years of experience in the air quality field, focusing on air dispersion modeling, air permitting, and GIS, to work with advanced technologies to provide new analytical modeling and methods showing realistic proof that landfills are not always a major contributor to odors and emissions. Why? Because contrary to allegations and citizen complaints in case studies:
When the modeling and data show differently, landfill owners and operators can more efficiently put controls and solutions in place.
The Rocky Mountain Chapter has reserved hotel rooms to ensure you enjoy a comfortable and memorable experience. These rooms are available at exclusive rates, providing you with both luxury and value. Book now and guarantee your spot. Phone: 1-888-525-1787, or go to www.breckresorts.com.
This Air & Waste Management Association specialty conference is the perfect event to provide an important basis for future development and advancements in the air quality modeling field. It will also provide in-person opportunities for stakeholders and regulators to discuss the challenges and techniques to model ever-tightening air quality standards.
The technical program will include an opening plenary session devoted to invited presentations by EPA’s Office Air Quality Planning and Standards (OAQPS) Air Quality Modeling Group (AQMG). Multiple sessions will cover key modeling topics, and the popular Town Hall Meeting will include an interactive Q&A format with high-level regulators and stakeholders.
Determining actual fugitive landfill gas/methane emissions from the landfill surface is hard to quantify. Drone methane and surface emission monitoring conducted on the landfill surface can determine methane concentrations at receptor points around the landfill surface. These receptor concentrations can be used to run an air dispersion model in reverse to solve for the emission rate of the entire landfill surface. This method also allows you to determine a more accurate control efficiency of the gas collection and control system at the landfill based on landfill gas/methane flow to the combustion device. Want to know more?
Jeff Leadford, PE, of SCS Engineers, is presenting “Modeling Fugitive Methane Emissions With Drones” – a not to miss session! Jeff puts his years of experience in the air quality field, with a focus on air dispersion modeling, air permitting and GIS together with advanced drone technology and modeling techniques demonstrating the effectiveness of combining them, especially for landfill owners and operators.
Other session topics include:
A revision to AP-42 regarding Municipal Solid Waste (MSW) Landfills was finalized on August 15, 2024. AP-42 is the Compilation of Air Pollutant Emission Factors guidance developed by the U.S. Environmental Protection Agency (EPA) to evaluate air pollution emissions from various sources. EPA drafted new emission factors for the MSW Landfill portion of AP-42 on January 12, 2024 and offered a 60-day public comment period that ended March 12, 2024.
Highlights of this final action include:
For additional information, please contact SCS Engineers, or visit the EPA Air Emissions Factors and Quantification website.
The commercial office sector in cities around the country is facing unprecedented challenges due to high vacancy rates that have been driven by factors including the work-from-home trend and the highest interest rates in almost 20 years. SCS Engineers worked with a panel of experts in the fields of economics, law, architecture, property development, and building sciences to explore the opportunities and challenges of the adaptive reuse of existing commercial buildings into new uses such as residential ones.
The resulting article provides valuable solutions and insight and can be found in Western Real Estate Business at this link: Western Real Estate Business April 2024 Page 20
SCS Engineers provides environmental consulting services for the real estate industry, including asbestos and lead-based paint surveys that are often needed before any building renovations or adaptive reuse. Once asbestos-containing materials or lead-based paint is identified at the building site, abatement activities to remove or mitigate the risks from these materials take place.
SCS monitors these abatement activities with air monitoring and inspections to make sure the removal is conducted according to regulations, and to protect workers and members of the surrounding community from exposure to these harmful chemicals; protecting and rehabilitating these spaces for re-occupancy.
About the Author: Cristobal Ramirez, CAC, is an environmental professional with over 20 years of experience in the United States, Canada, and Mexico. As a bilingual speaker in Spanish and English, he provides environmental services for clients in the United States and Mexico. His experience includes completing over 2,000 environmental assessments and implementing remediation activities for contaminated properties. He is an expert in performing Environmental Site Assessments (ESAs) according to U.S. EPA 40 CFR, Part 312, Standards and Practices for All Appropriate Inquiry (AAI); and Final Rule and American Society for Testing and Materials (ASTM) Standard Practice for Environmental Site Assessments: Phase I Environmental Site Assessment Process E 1527-13. In addition to ESA services, he conducts subsurface investigations, health and safety plans, community health and safety plans, geophysical surveys, soil vapor surveys, health risk assessments, remediation conceptual cost estimates, property mitigation plans, and soil reuse plans.
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