The Minnesota Department of Health (MDH) published ambient air limit in July 2021 for PFAS. Specifically, MDH has developed Risk Assessment Advice (RAA) for PFOS and PFOA in air at a concentration of 0.011 microgram per cubic meter μg/m3 and 0.063 μg/m3, respectively, which applies to short-term (24-hr), subchronic (> 30 days) and chronic (> 8-yr) toxicological impacts2. A longer duration RAA value representing acute and cancer risk has not been determined. This Air Guidance Value (AGV) represents the maximum concentrations at which little or no health risk is expected for humans, including vulnerable subpopulations, that are exposed to airborne PFOS or PFOA3. MDH does not specify or enforce any application of the AGV at present.
In the February 2020 PFAS Action Plan1, the Environmental Protection Agency (EPA) identified characterizing and understanding the environmental impacts of per- and polyfluoroalkyl substances (PFAS) in ambient air as an important step in addressing potential impacts associated with these emerging contaminants.
Related Services
EPA Made a Commitment
To “develop sampling and measurement methods for PFAS in air, assess effectiveness of PFAS disposal methods, and understand the effectiveness of PFAS emission controls” as part of the action plan. It also provided states with technical support on destruction technologies for PFAS such as incineration. Individual states are also taking initiative to establish ambient air PFAS (more specifically perfluorooctanoic acid [PFOA] and perfluorooctanesulfonic acid [PFOS]) threshold screening and risk assessment levels building on the EPA PFAS Action Plan. Here is a brief overview of the states that have published and implemented PFAS air-related thresholds as of August 2021.
On January 13, 2021, the New York State Department of Environmental Conservation (NYSDEC) proposed an allowable concentration in ambient air – called an Annual Guideline Concentration (AGC) – for PFOA. As of February 12, 2021, New York joined Michigan as one of the few states with established air quality limits on PFAS as the AGC for PFOA is now listed in the NYSDEC DAR-14, reflecting a state-only policy. NYSDEC routinely reviews and adjusts AGCs based on the evolving science.
The listed AGC for PFOA is 0.0053 μg/m3, expressed as an annual average. NYSDEC classifies PFOA as a high-toxicity air pollutant, meaning that the state sets an annual emission limit above which air dispersion modeling will be required to show compliance with the AGC per NYSDEC 6 CRR-NY III A 212-25. These limits range from 0.0001 pounds per year (lb/yr) for dioxins to 5,000 lb/yr for lower toxicity compounds. Because PFOA in not listed in Table 2 in NYSDEC 6 CRR-NY III A 212-2.2, for a source for “which the actual annual emission rate is greater than 100 lb/yr facility-wide, the applicant shall submit the contaminant’s hourly [emission rate potential] ERP associated with each emission source. Actual annual emission rates less than 100 pounds per year after the use of a control device must meet the provisions of 212-1.5(g)”6. Thus, TRC anticipates facilities with PFAS > 100 lbs/yr uncontrolled emissions will be required to document compliance with NYSDEC’s AGC.
On February 5, 2018, the Michigan Department of Environment, Great Lakes, and Energy (EGLE) established a PFOA, PFOS, and/or combined advisory screening level of 0.07 μg/m3. If an air permit from EGLE is required for a new or modified source, EGLE’s air toxic rules would apply. If PFOA or PFOS emissions individually, or the combined emissions of the two compounds, are above the thresholds (over a 24-hour averaging time) and the source is not exempt, the source would need to demonstrate compliance with health-based screening levels before being issued an air permit from EGLE.
Since early 2000s, the New Hampshire Department of Environmental Services (NHDES) has had ambient air limits of 0.05 μg/m3 (on a 24-hour averaging period) and 0.024 μg/m3 (on an annual averaging period) for ammonium perfluooctanoate (APFO) under New Hampshire Code of Administrative Rules, Chapter Env-A 1400, Regulated Toxic Air Pollutants7. APFO dissociates in water to form PFOA.
A 2006 NHDES Administrative Order required Saint-Gobain Performance Plastics (SGPP), which operates a facility in Merrimack, NH that manufactures polytetrafluoroethylene (PTFE) coated fiberglass and PTFE films, to use fluoropolymer coatings that contain less than 75 parts per million APFO. SGPP was required to conduct stack testing in 2016 and 2018. Based on the results of those tests, NHDES Air Resources Division issued a Temporary Permit (i.e., Permit to Construct) to SGPP in February 2020 which authorized SGPP to install a regenerative thermal oxidizer (RTO) to meet Best Available Control Technology (BACT) standards, specified under NH RSA 125-C:10-e, Requirements for Air Emissions of Perfluorinated Compounds Impacting Soil and Water. This was part of the long process for the final installation of the RTO in July 2021 to remove “air perfluorinated compounds (PFCs)”, specifically PFOA, from SGPP’s exhaust stream prior to release to the atmosphere.
Similar to NHDES, the Texas Commission on Environmental Quality (TCEQ) had also previously listed in 2003 an “Effects Screening Level” (ESL) for APFO of 0.1 μg/m3 and 0.01 μg/m3 on a short and long term averaging basis, respectively. More recently in 2011, TCEQ also added ESL values for PFOS and PFOA of 0.1 and 0.05 μg/m3 for short term, respectively, and 0.01 and 0.005 μg/m3 for long term, respectively. During the permitting phase, a facility would need to demonstrate compliance with these concentrations when a project is found to trigger off-property air quality impact requirements.
Conclusion
As summarized in the below table, the approach each state is taking to addressing PFAS chemicals in sources’ air emissions varies by quantity and definition, with standards ranging from 0.005 μg/m3 to 0.07 μg/m3.
Industries in these states that may have PFAS (specifically PFOA and/or PFOS) emissions will need to pay special attention to whether additional modeling, measurement or permitting requirements are triggered. States that have not yet published ambient air PFAS standards are currently collecting data that may be used to establish state-specific standards. For example, North Carolina has conducted a year-long statewide study of PFAS wet and dry deposition8, which may be utilized by the state to guide development of air emission PFAS standards. TRC expects more states to establish PFAS air standards and will continue to monitor developments on a state by state basis to keep our clients informed.
Resources
EPA, EPA PFAS Action Plan: Program Update, February 2020
EPA, EPA PFAS Action Plan: Program Update, February 2020 Published February 4, 2020
Air Guidance Values
Published
Air Durations
Published April 1, 2020
NYSDEC, DAR-1, Guidelines for the Evaluation and Control of Ambient Air Contaminants Under 6NYCRR Part 212
Published February 12, 2021
NYSDEC, Title 6, Chapter III, Subchapter A, Part 212
Published
Sharing Our Perspectives
Our practitioners share their insights and perspectives on the trends and challenges shaping the market.
EPA Signs New Rule Affecting Air Emissions from Stationary Combustion Turbines
September 16, 2024
EPA finalized the residual risk and technology review (RTR) of the National Emission Standards for Hazardous Air Pollutants (NESHAP) for Stationary Combustion Turbines.
Regulatory Updates
EPA Proposes New Guidance on Air Quality Analysis for Permits
January 5, 2024
On October 23, 2023, the US EPA proposed changes to the Guideline on Air Quality Models and the US EPA model AERMOD
Resources
Modeling of Fogging and Icing Events
December 14, 2023
In recent years, various agencies across the country have become committed to understanding the impacts of fog generated by cooling systems. At first glance, fog created by cooling towers may not appear to be a significant problem, however, it can have adverse effects on the public. Fog can impair visibility for people driving on roads and if temperatures are below freezing, fog can cause the formation of rime ice on surfaces. To understand the consequences of fog created by these cooling systems, experts have devised advanced modeling techniques.
Regulatory Updates
EPA Issues Information Collection Request for Plywood and Composite Wood Products Source Operators
March 17, 2022
EPA issued an Information Collection Request (ICR) to develop new emission standards for inclusion in the Plywood and Composite Wood Products (PCWP) National Emissions Standards for Hazardous Air Pollutants (NESHAP).
Regulatory Updates
EPA Lifts Stay of Standards for New Lean Premix and Diffusion Flame Gas-fired Combustion Turbines
March 14, 2022
The EPA Administration signed a notice to finalize amendments to the National Emission Standards for Hazardous Air Pollutants (NESHAP) for Stationary Combustion Turbines
News
TRC Acquires United Sciences Testing, Inc., Expanding Air Management Capabilities
February 23, 2022
TRC Companies (“TRC”), announced the expansion of its Air Management capabilities with the acquisition of United Sciences Testing, Inc. (USTI), who provides emissions testing services to utility and industrial clients within the Great Lakes and Midwest regions of the US.
Insights
Air Emissions Permitting: What Analytical Laboratories Need to Know About Compliance
December 18, 2021
The independent testing of liquid and solid samples is a critical way that businesses demonstrate regulatory compliance. The laboratories that perform these analyses are also subject to environmental rules and should closely track their operations to ensure they are meeting compliance obligations.
Regulatory Updates
EPA Proposes Changes to Methane Control at Petroleum Operations
November 10, 2021
New Source Performance Standard for Methane Control at Petroleum Operations in 2022
Regulatory Updates
PFAS Air Emissions Standards and Trends for Summer 2021
August 17, 2021
Environmental impacts of PFAS in ambient air leads to states implementing PFAS air-related thresholds.
White Papers / Reports
Managing EHS & ESG Risks Through Integrated Systems Today and Beyond
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It has been more than 50 years since the development and establishment of the federal Environmental Protection Agency (EPA) and the federal Occupational Safety & Health Administration (OSHA) which were formed to protect our environment and workplaces across the United States. Significant laws, policies and regulations followed to establish the “regulatory programs” that all applicable businesses and entities must address and meet to ensure these compliance-driven legislative programs would create a foundation to protect our society.
Regulatory Updates
EPA Proposes New Emissions Limits for Combustion Turbines
May 22, 2021
After 15 years of legal limbo, combustion turbines could be facing new emissions standards under a proposal introduced by the EPA.
Regulatory Updates
EPA Ramps Up Inspections and Enforcement Actions
May 14, 2021
EPA’s acting enforcement chief, Larry Starfield, directs agents to ramp up inspections in communities known to be afflicted by pollution
Regulatory Updates
South Coast Air Quality Management District Rule 2305: Warehouse Indirect Source Rule
April 7, 2021
The rule is intended to reduce local and regional emissions of NOx and diesel particulate matter (PM).
Regulatory Updates
EPA Finalizes Reversal of “Once In Always In” Air Pollution Policy
November 18, 2020
On October 1, 2020, the EPA finalized a ruling that no longer enforces the “once in, always in” air emissions policy.
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TRC Awarded a Yahara WINS Grant
August 28, 2020
TRC was recently awarded a Yahara WINS grant to develop a pilot scale simple aeration method for removing phosphorous from the discharge of manure digesters. The grant application was developed and submitted by: Bob Stanforth, Alyssa Sellwood, Mike Ursin, Ted O’Connell, Ken Quinn, and John Rice, who are members of multiple TRC CORE teams.
Regulatory Updates
New York State Finalizes Emission Limits for Power Generators
January 21, 2020
On January 16, 2020, the New York State Department of Environmental Conservation (NYSDEC) finalized a rulemaking limiting nitrogen oxide (NOx) emissions from existing simple cycle and regenerative peaking combustion turbines with a nameplate capacity of 15 megawatts (MW) or greater during the ozone season (May 1 – October 31).
Regulatory Updates
New York State Proposes Emissions Limits for Power Generators
March 22, 2019
On February 27, 2019, the New York State Department of Environmental Conservation (NYSDEC) released a proposed rulemaking limiting nitrogen oxide (NOx) emissions from existing simple cycle and regenerative peaking combustion turbines with a nameplate capacity of 15 megawatts (MW) or greater during the ozone season (May 1 – October 31).
