Barr has been measuring per- and polyfluoroalkyl substances (PFAS) in stack emissions at facilities in the U.S. for two decades. Because of this experience, a confidential manufacturing client hired Barr to perform compliance testing to evaluate the performance of thermal oxidation as a best available control technology (BACT) to control PFAS emissions from its processes.
Barr conducted stack testing for EPA OTM-45, Method 25A hydrocarbons, 26A hydrogen fluoride, and EPA 204 capture efficiency. We wrote the test plan, performed testing, and prepared the report. The test results satisfied all permit requirements. The determination of BACT and incorporation of PFAS emission limits in the permit was among the first such instances in the U.S. and was based on the potential to cause or contribute to surface or groundwater contamination.
Our experience in this area dates back more than 20 years, when we participated in an industry-wide mass balance study to measure air, water, and solid waste releases of PFOA (perfluorooctanoic acid, a type of PFAS) to the environment from 2003 to 2005. The study involved the development of sampling methods with full Quality Assurance Project Plans (QAPP). During the study, Barr’s stack test engineers developed an early version of modified Method 5 that was accepted by the EPA in the study docket.
Subsequently, Barr conducted stack tests to evaluate emissions, control-device effectiveness, and emission reduction due to reformulation of input materials to manufacturing processes. Barr has also performed indoor air quality and ambient air measurements for PFAS compounds.
Our work contributed to the development of OTM-45, published in January 2021 through submission of a separate and complete set of stack samples to EPA-ORD to further method development. Barr’s stack test emissions data has been used as input to air, soil, and hydrogeologic modeling to understand PFAS fate and transport as well as the impact of air emissions on surface and groundwater.