Are Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS) Air Pollution?

The Primary Author was present at the very first WEF Odor Specialty Conference when the title was essentially related to Odor and VOCs. At the time, the 1990 Clean Air Act Amendments were just being incorporated into practice, and there was a significant potential concern for wastewater treatment plants, especially larger plants and utilities that they would become title V sources of air pollution. There were many cutting edge chemical fate models proposed and discussed for estimating air emissions from individual and total VOCs. Over the years, it became clear that wastewater plants were not going to be regulated as the large major sources of VOCs. And what was even clearer was that many industrial loadings, sludge thickening or destruction practices could create air toxic emissions, so the title of this bi-annual conference was changed to focus on Odors and Air Toxics. Air toxics were, and still are, a unique form of air pollution. Currently the secondary focus is on the much broader topic of air pollution, of which odors is technically a subtopic of air pollution, but remains in the specialty conference title and driver for it, simply because it has been the number one air pollution concern to wastewater and water infrastructure and treatment. As VOCs, mercury, lead, dioxins and furans, and other chemicals of concern have literally bubbled to the surface, the one constant, as we come up on the 30-year anniversary of these specialty conferences, has been odor. We are now of the brink of another potential contaminant of concern, and that is airborne PFAS exposure. When the primary author was a junior engineer, at one of the largest wastewater engineering firms in country, he always thought it was amusing that the head of his group, the Air Quality and Odor Control Group, had to explain each year on some standard form why the AQ group was an integral part of the company's services. He suggested that the head of his group simply respond with a question: 'Because all environmental concerns are transported in air, water, and land, so how could our 'full-service firm' focus on only one or two, out of the three?' The environmental concerns with PFAS seem to be approaching the tipping point of the same question. 'How do we discuss a persistent and widespread compound of concern in drinking water without considering the effects on and from the land or air?' The primary author is on the Board of Directors for the North East Biosolids and Residuals Association (NEBRA), so he is very familiar with the land application concern that is on-going. But until now, air has been considered a possible pathway, for distribution but with limited direct effect on humans. That is now changing with the EPA PFAS Strategic Roadmap was issued in October 2022 . Like the Clean Air Act Amendments that took a few years to potentially affect the water industry, the PFAS concern is doing the same, soon it will be an air quality concern as well. with the development and publishing of the PFAS Roadmap there has been more urgency placed on understanding the viability of the only EPA proposed air sampling method for PFAS at this time. The OTM-45 stationary source test method is essentially a semi-volatile organics compound method modified from one similar to the solid semi-volatile method used for the solid waste industry. What is interesting with this method is that the method, not formally approved by EPA, will soon be available for states to include in their next revision of their SIP program. But what so we know about this test method and other potential methods? The focus of this paper is to explore this method, describe it, discuss the pros and cons, and other possible alternatives. In addition, at least one state has an ambient air quality limit for PFAS compounds. This paper will also discuss how the method can and cannot fit into the typical wastewater treatment plant air toxics dispersion modeling approach some plants need to undertake today to obtain an air permit. Both the primary author and the secondary author work at an air quality firm that has been around for nearly four decades. It was founder by an individual that spent the early part of his career developing the original dispersion models for EPA. The secondary author is a meteorologist and will provide insight into the viability of using today's AERMOD with the current data derived from the test methods, and also what it means. This white paper abstract is purposely vague at this time because it is unclear which studies will be the final focus of the paper at the time. The research is changing that fast for PFAS in general, and for air implications even faster because it is only now bubbling to the surface. For example, just in the last week, the EPA released research money grants for three studies to examine the exposure pathways further with respect to indoor air concerns exceeding outdoor air concerns. This is a follow-up to a 2021 study by one of the firms in the newly funded studies, which should have shown that the water industry is not a concentrator of exposure, but instead, when covered in the press, the conclusion was to promote stricter regulations 'such as the one recently passed in Maine'. Now to us, we know they are referring to the very boring law that is vaguely 'requiring' PFAS source reduction, not LD1911 which is the law banning land application of biosolids in Maine. Unfortunately, the majority of all Mainers are familiar with, or becoming familiar with, LD1911 because it is increasing their water treatment bills. And the fact that it was unanimously approved the legislature. This paper is intended to help us get out in front on the air issues as much as possible to prevent the same misinformation and grouping of the 'water industry' in with 'industry' in general, which is the source of these manmade PFAS compounds. This paper focuses on the methods that will be used for indoor, outdoor, and stationary sources, and how the data can benefit the water industry. With clear exposure pathways outside of drinking water, it can help the water industry deemphasize the current 'The buck stops for PFAS at the treatment plant' approach. And while the PFAS discharge and biosolids train may have left the station, this paper and presentation will help inform facilities that this PFAS air quality train is coming soon, through a summary of pertinent air sampling methods, emission estimating and dispersion modeling possibilities.