USEPA’s Reconsideration of Ozone and PM2.5 National Ambient Air Quality Standards and Environmental Justice

Synergies, Implications and Recommendations

Tuesday, May 24 | 2:00–3:00 pm EDT

About the webinar

In 2021, USEPA announced it would reconsider the previous administration’s decision to retain the National Ambient Air Quality Standards (NAAQS) for particulate matter and ozone in order to include more recent scientific evidence regarding the adequacy of the current standards to protect public health and welfare as required by the Clean Air Act.

On March 18, 2022, the Clean Air Scientific Advisory Committee (CASAC) released the "CASAC Review of USEPA’s Policy Assessment for the Reconsideration of the NAAQS for PM"1 and recommended lowering both the annual and 24-hour PM2.5 standards. In May, USEPA will release its final Supplement to the 2019 Integrated Science Assessment for Particulate Matter, and USEPA has also just released a Draft Policy Assessment for the ozone standard. Among other factors, the NAAQS reconsideration includes information related to exposure and risk disparities by race/ethnicity and socioeconomic status as part of the decision.

The reconsideration of the particulate matter and ozone NAAQS may have significant implications depending on the stringency of the new standards.

New standards may catalyze further policy and regulatory change for disproportionately impacted communities. Beyond NAAQS reconsiderations, environmental justice activity and policy activity at the federal level continues to develop under the Biden Administration. USEPA recently released screening tools2, including EJScreen 2.03 and the new AirToxScreen. State and local agencies are also actively developing their own policy, regulatory requirements, environmental justice tools and public engagement strategies.


1CASAC. 2022. March 18.
2USEPA. 2022.
3Broadly, the new version of the software, known as EJScreen 2.0, is designed to help government agencies make more accurate permitting, enforcement, compliance, and outreach decisions, consistent with President Joe Biden’s goal of addressing environmental justice.

Register now

What will you learn?

We'll discuss the changing regulatory landscape including:
  • What are the NAAQS?
  • What prompted this reconsideration?
  • How will these proposed changes affect the regulated community in years to come?
  • What is environmental justice?
  • How are environmental justice factors affecting the reconsideration?
  • How is USEPA addressing the environmental justice movement?
  • What new and revised screening tools are available, and how will they be used?
  • How may evolving federal, state and local environmental justice policies impact regulatory requirements?

Learn from industry experts

Join our experts as they share insights on USEPA’s reconsideration of NAAQS for particulate matter and ozone, and environmental justice.

Scott Adamson, CCM

Senior Managing Consultant

Scott specializes in collecting and analyzing ambient meteorological and air quality data for industrial clients in the mining, oil & gas, and power sectors and government agencies, including WDEQ, UDAQ, IDEQ, CARB, SMAQMD, CDPH, Ohio EPA, USEPA Regions V, VIII, and IX, and the British Columbia Ministry of Environment and Climate Change. His expertise includes design, quality assurance project plan development and agency negotiation, instrumentation integration, and execution of meteorological and air quality monitoring programs. His expertise also extends to air dispersion modeling and air quality data statistical analyses to establish regulatory compliance with national and state ambient air quality standards, develop a scientific understanding of the spatial and temporal distribution of emission source impact on air quality, and provide air quality information to the public.

Kelli Calhoon

Senior Managing Consultant

Kelli has managed projects in environmental consulting for over 20 years, with specific expertise in air quality and significant interest and knowledge in environmental justice policy. She has extensive experience with Title V permitting and compliance programs, state and PSD permit applicability review and applications, and NSPS and NESHAP compliance. She also has proficiency in the development of annual emissions reporting, corporate greenhouse gas inventories, environmental management systems, Tier II reporting, toxic release inventory reporting, and environmental auditing. She successfully manages projects for individual sites and for corporate fleets with multiple sites across the country. She serves clients in many industries, including petroleum products terminals, oil and gas production and processing, power generation, data centers, cement manufacturing, non-metallic mineral processing, distilling, metals manufacturing and surface coating, as well as numerous other general manufacturing industries.

Megan Neiderhiser, PE


Megan leads Ramboll's regional air quality group and has extensive experience in air quality management, specifically air dispersion modeling, air permitting and compliance, CEQA analysis, human health risk assessment and NEPA evaluation. Her expertise also covers emissions estimation, greenhouse gas management and sustainability planning. Megan works regularly with industrial, mining and public entity clients. She has worked with several air agencies, including BAAQMD, BLM, CDPHE, IDEQ, UDAQ and USEPA Region 8, and has experience with many emissions and modeling software tools, including AEDT, AERMOD, CalEEMod and MOVES. 

Courtney Taylor

Senior Managing Consultant

Courtney specializes in atmospheric modeling, statistical techniques, emissions inventory development and review, legal support services, ambient air monitoring and project management/advising. She translates complex modeling results into approachable concepts with an emphasis on model suitability and outcome-oriented study design. Courtney’s diverse project experience includes State Implementation Plans (SIP), National Environmental Policy Act (NEPA) analyses, Resource Management Plans (RMPs), Prevention of Significant Deterioration (PSD) permits and minor source permits. The analyses have included many industrial sectors, including oil & gas; coal mining, gold mining and uranium mining; coal- and natural gas-fired electricity generation; and ethanol production.

Our services in air quality

Ramboll’s air quality professionals apply cutting-edge science and methodologies to the development of tailored solutions to facility, local and regional air quality issues. Our worldwide practice is characterized by the highest level of technical and scientific skills, informed by the specific needs of our clients.