Mitigating PFAS in Drinking Water Through Analytical Innovation

Introduction Per- and polyfluoroalkyl substances (PFAS) have gained significant attention as an emerging environmental and safety threat in the United States. Since the 1940s, PFAS are ubiquitous in industrial usage due to their chemical stability, thermal stability, and high resistance to degradation. Sources of PFAS include chemical manufacturers, which release PFAS during thermal treatment of waste and products of incomplete combustion. Additionally, PFAS are found in a variety of products including fire extinguishing foams, cosmetics, food packaging, non-stick cookware, and cleaning supplies. Bioaccumulation at production sites and landfills enable PFAS compounds to leach into the ground and surface water. Contaminated PFAS water is then utilized for human consumption and agricultural applications without the appropriate measures to remove the contaminated particles. The Environmental Protection Agency (EPA) has developed a regulatory strategy to help address PFAS contamination in drinking water. Regulations, such as the Fifth Unregulated Contaminate Monitoring Rule (UCMR 5), are extremely relevant now since public water systems require analysis of PFAS, with over 10,000 water systems in need of analysis. The sampling period ends 2025, where sampling data is to be collected and analyzed for 2026 review. There are several analytical challenges when assessing PFAS including ultra-sensitivity capabilities for analytes, larger sample sizes, laborious sample preparation and the removal of contamination sources of PFAS within the analytical equipment and external sources. To determine the low levels of PFAS, researchers require a highly sensitive mass spectrometer or a sample preparation technique that includes a concentration step. Coupling solid phase extraction (SPE) with LC/MS/MS has been one of the most popular approaches to PFAS analysis in aqueous samples and has been implemented in EPA Method 537.1 and 533. Utilizing Methods 537.1 and 533, PerkinElmer has successfully developed and validated a LC/MS/MS method that has increased throughput, removed contamination risk, and decreased runtimes by nearly 70% for PFAS analysis in drinking and surface water samples by coupling a LX-50 UHPLC system to a QSight 420 triple quadrupole mass spectrometer. In this whitepaper, discover key insights into regulatory requirements and the latest analytical innovations to optimize PFAS analysis. WHITE PAPER Mitigation of PFAS in Drinking Water Through Analytical Innovation Mitigation of PFAS in Drinking Water Through Innovation and Environmental Justice www.perkinelmer.com 2 DRINKING WATER Applying the Maximum Contaminant Level (MCL) process for PFOA and PFOS, the two most ubiquitous PFAS chemicals, and determining if regulation is needed for a broader class of PFAS. The next step for the SDWA process is to develop standards to propose a regulatory determination to help provide an opportunity for the public to gather information related to further PFAS regulations in drinking water. CLEANUP Interim groundwater cleanup recommendations are being continuously developed to hold responsible parties accountable. TOXICS The EPA is considering additional PFAS chemicals to add to the Toxics Release Inventory, critical to opening information on certain PFAS reported in industrial sectors and federal facilities, and provide rules to prohibit their use. MONITORING The EPA is proposing a nationwide monitoring of PFAS under the next UCMR monitoring cycle for drinking water to enhance understanding of frequency and concentration of PFAS. RESEARCH Continued research will be significantly increased to provide a better understanding of risks associated with PFAS, which includes optimized detection and measurement methods. ENFORCEMENT The use of enforcement tools will be applied using federal enforcement authorities. RISK COMMUNICATIONS The EPA will develop collaborations with federal, state, tribal, and local partners to promote a risk communication toolbox consisting of multi-media materials and messaging. EPA’s PFAS Action Plan EPA’s PFAS Action Plan provides an overview of the steps the agency is taking to address PFAS and to protect public health. The PFAS Action Plan focuses on providing short and long-term solutions as a response from the public input the agency has received since the PFAS National Leadership Summit. The key actions EPA is outlined in Figure 1 below1 The EPA's Approach to PFAS EPA’s integrated approach to PFAS contains three central directives that focus on improving PFAS contamination.2 Research The EPA is investing in research and development to better understand PFAS exposure and toxicity. Research includes examining the lifecycle of PFAS, ensuring science-based decision making to define categories of PFAS and methods, understanding sources of contamination and exposure pathways, and consideration of how the burden of PFAS pollution impacts communities. Restrict The EPA will focus on the prevention of PFAS from entering the environment and holding polluters accountable using statutory authorities. They will also establish voluntary programs to reduce PFAS emissions and prevent or minimize the impact of PFAS emissions on all communities. Remediate To facilitate a rapid and overarching remediation of PFAS contamination, the EPA will leverage the power from statutory authorizes to maximize the funding and performance of responsible parties, accelerate the execution of treatment and disposal of PFAS, and prioritize the protection of disadvantaged communities through the equitable access of PFAS solutions. Mitigation of PFAS in Drinking Water Through Innovation and Environmental Justice www.perkinelmer.com 3 Rule Review Final Regulatory Determinations Six-Year Review of Existing NPDWRs Preliminary Regulatory Determinations Final Rule (NPDMR) Proposed Rule (NPDMR) 18 months 24 months Public Review and Comment Research Needs Assessment May develop health advisory guidelines No further action required if decision is to not regulate UCMR UCMR Monitoring Results Final UCMR Draft UCMR Regulatory Determination Safe Drinking Water Act Regulatory Process CCL Final CCL Draft CCL Safe Drinking Water Act and Regulatory Process The Safe Drinking Water Act (SDWA) utilizes risk and datadriven processes to assess water contaminants. As a result of SDWA, the EPA requires water systems to conduct sampling for unregulated contaminates every five years. In March 2021, the EPA published the Fifth Unregulated Contaminant Monitoring Rule (UCMR 5), proposing critical new data to improve the EPA’s grasp on the frequency of 29 PFAS compounds found in the nation’s drinking water and, specifically, at which levels. UCMR 5 is expected to expand the number of drinking water systems participating in them, generating data that will optimize their ability to conduct state and local assessments of contamination.3 The Safe Drinking Water Act regulatory process begins with the draft of a contaminant candidate list (CCL). Once finalized, the CCL is used to create a UCMR, with monitored results. Figure 2: Safe Drinking Water Act Regulatory Process. EPA pre-sampling activity will commence in 2022, the sampling period will take place between 2023-2025, and the postsampling activity will occur in 2026. The UCMR 5 states that all public water systems serving 3,300 or more people and 800 representative public water systems serving fewer than 3,300 would collect samples during a 12-month period from January 2023 through December 2025. Future considerations regarding UCMR development include prioritization of additional PFAS for the inclusion of UCMR 6, as improved techniques to measure PFAS are developed and validated.4 Together, the CCL and UCMR are utilized to determine preliminary regulatory determinations and subsequent final regulatory determinations. At this point, no action is required if a decision is to not regulate. However, if a decision is made to regulate, the final regulatory determinations will yield a proposed rule in 24 months. Upon which, a final rule, called the National Primary Drinking Water Regulation (NPDWR), is instituted after an additional 18 months. Concluding the regulatory process is a six-year review of existing NPDWRs. Figure 2 summarizes the Safe Water Act Regulatory Process.3 Regulatory Background and UCMR 5 Program In 1974, SDWA was developed by the EPA to protect drinking water quality. In 1986, amendments required 25 new MCLs every 3 years, restricting lead usage, initiating the state revolving loan fund and serving as a pre-cursor to the CCL. In 1996, additional amendments incorporated risk-based standards, establishing CCL and UCMR. Additionally, substantial infrastructure funding was instituted with annual CWSs reporting. 1. UCMR 5 Program The UCMR 5 Timeline began its development in 2018‑2020, where several stakeholder meetings were held. Post Proposal initiative implementation began in 2020 kicking off the lab approval program, SDWARS registration and inventory notifications for PWSs, partnership agreements, state monitoring plans and PWS inventory. Last year, the UCMR 5 published its final rule on 12/27/21.4 Mitigation of PFAS in Drinking Water Through Innovation and Environmental Justice www.perkinelmer.com 4 The following are key definitions critical to understanding the UCMR 5 scope: n Public Water System (PWS): Provides water for human consumption via pipes/other constructed conveyances to at least 15 service connections or serves an average of at least 25 people for 60+ days a year n Community water System (CWS): PWS that supplies water to the same population year-round n Non-transient, Non-community Water Systems (NTNCWS): PWS that supplies water to at least 25 of the same people at least 6 months of the year/not year-round n Transient, Non-Community System Water System (TNCWS): PWS that supplies water where people do not remain for long periods of time 2. Key Changes from UCMR 4 to UCMR 5 Key changes that have occurred from UCMR 4 to UCMR 5 include: n Elimination of different requirements based on system size, no monitoring tier list n Applicability expanded to all CWS/NTNCWS serving 3,300+ n 800 Randomly selected PWSs serving <3,300 AWIA of 2018: Funding expanded PWS scope for EPA to cover shipping and analytical costs of samples.4 3. UCMR Implementation Team and Sampling Design The EPA has customized its role and supporting directives to small and large PWSs. For small PWSs their role includes maintaining UCMR lab approval and contracts to support UCMR, compile contact and inventory info, execute sample kit distribution and tracking, review SDWARS data and report to NCOD, and use SDWARS for outreach.4 For the UCMR Laboratory Program, the EPA is responsible for the following for small PWSs: n Funding costs for sampling kits, sample shipping and analyses n Engaging with States and PWSs for collecting samples n Coordinating with contract labs for samples analyses and payment for services n Reviewing results and QC data n Reporting out results to States and PWSs via SDWARS For large PWSs their role involves reviewing SDWARS data for completeness, reporting to NCOD, supporting users of SDWARS system, updating PWS inventory and schedules as needed, providing technical assistance, and utilizing SDWARS for outreach.4 For the UCMR Laboratory Program, the large PWSs are responsible for: n The costs of samples analyses n PWS coordinates sample shipping and analyses with EPA-approved UCMR 5 labs n Labs post data to SDWARS n PWS reviews and approves data in SDWARS n States have access to results following large PWS review period UCMR implementation is divided between three entities: EPA Office of Ground and Drinking Water, EPA Regional Offices, and Partnering States. See Figure 4 for a breakdown of the responsibilities of each member of the UCMR Implementation Team.4 Partnering States EPA Regional Offices Support aspects of implementation based on State specific interest Assist States and PWSs with UCMR requirements and compliance Coordinate State Partnerships Lead for implementation of UCMR 5 EPA Office of Ground and Drinking Water UCMR Implementation Team Figure 3: UCMR Implementation Team and Responsibilities. 4. UCMR Sampling Design, Monitoring, and Reporting Design Sampling design is vetted with stakeholders and is peer reviewed, with 800 randomly selected small PWSs (serving less than 3300) notified by 02/22/22. The data quality objectives were outlined as follows: n Occurrence data for unbiased national exposure estimates n Representative of both PWS size and source water type n Population weighted n At least 2 small systems are selected for each state Mitigation of PFAS in Drinking Water Through Innovation and Environmental Justice www.perkinelmer.com 5 Monitoring The EPA is seeking to add funding to cover all 3300-10,000 ppl PWSs, however, it is currently only covering 8%. The current strategy used to assess the monitoring includes determining the national contaminant occurrence, develop a primary tier and scope, utilize available methods and common techniques, and ensure consistency with AWIA provisions.5 Reporting The Minimum Reporting Limit (MRL) is the minimum quantitation level that, with 95% confidence, can be achieved by analysts at 75% or more of US labs using a specific method. The EPA establishes MRL using data from multiples labs performing “Lowest Concentration Minimum Reporting Level (LCMRL) studies to identify capability. Each lab's lowest concentration MRL (LCMRL) is the lowest true concentration for which future recovery is predicted to fall, with high confidence at 99%, between 50%-150% recovery. Thus, the LCMRL is the lowest concentration that specified quality measurements can be made by a lab. The MRL functions to produce quality and consistency across UCMR labs, while balancing lab capacity.6 5. UCMR Process for Lab Participation and Cost The process for lab participation in UCMR takes approximately 3-6 months and involves six steps. See Figure 4 for the UCMR lab participation process overview.7 Request to Participate 6. Formal Approval by EPA 5. Proficiency Testing 4. EPA Review Application 3. Complete Application 2. Register 1. Request to Participate Process for Labs Participation in UMCR ~3-6 Month Process Figure 4: UCMR lab participation process overview. Key changes made from UCMR 4 to UCMR 5 for a lab’s participation include: n When registering, UCMR 4 stated that to participate as a UCMR lab, the lab had to register within 60 days of final rule publication (12/20/16) and application within 120 days. UCMR 5 now states that to participate as a UCMR Lab, registration and application must be completed by 08/01/22. These changes were enacted to provide greater flexibility for interested labs. n Regarding proficiency testing (PT), EPA plans to offer 3 PT studies prior to 12/27/21 (final rule pub) and 3 PT studies after 12/27/21. As of Jan 2022, 18 labs have been approved for UCMR 5, with additional PT studies expected to be added. Based on the current funding, the number of small PWSs participating is ~1,200, with a high demand of more approved labs.7 See Table 1 for the approximate cost for UCMR 5 Sample Sets and the estimated cost of the proposed UCMR 5 over the five‑year cycle. Table 1: The approximate cost for UCMR 5 Sample Sets and the estimated cost of the proposed UCMR 5 over the five-year cycle. Approximate Cost for UCMR 5 Sample Sets Method Type Average Analysis Cost per UCMR 5 Sample1 25 PFAS using EPA Method 533 (SPE - LC/MS/MS) $376 4 PFAS using EPA Method 537.1 (SPE - LC/MS/MS) $302 1 Metal using EPA Method 200.7 (ICP-OES/AES) or M2 or ASTM3 $62 Estimated Total2 for 1 UCMR 5 Sample Set $740 1 The average analytical cost was determined by averaging estimates provided by four drinking water laboratories 2 Standard Method (SM) 3120 B or SM 3120 B-99 3 ASTM International (ASTM) D1976-19 Approximate Cost for UCMR 5 Program Est. Average Annual Cost of the Proposed UCMR 5 Over the Five-year Cycle1 PWSs Entity Average Annual Cost (Million) (2022-2026)2 Small Systems (<10,000), including labor3 only (non-labor costs4 paid by EPA) $0.3 Large Systems (10,001 – 100,000), including labor and non-labor costs $7.2 Very Large Systems (>100,000) including labor and non-labor costs $2.3 States, including labor costs related to implementation coordination $0.8 EPA, including labor for implementation and nonlabor for small PWSs testing $10.5 Average Annual National TOTAL for 1 UCMR 5 2023-2026 $21.1 1 Based on the scope of small-system monitoring described in AWIA 2 Totals may not equal the sum of components due to rounding 3 Labor costs pertain to systems, States, and EPA. Costs include activities such as reading the rule, notifying systems to participate, sample collection, data review, reporting, and record keeping 4 Non-labor costs will be incurred primarily by EPA and by large and very large PWSs. They include the costs of shipping samples to labs for testing and the cost of analysis Mitigation of PFAS in Drinking Water Through Innovation and Environmental Justice www.perkinelmer.com 6 6. PWS’s Sampling Program The Ground Water Representative Monitoring Plan Program (GWRMP program) is an option for PWSs with ground water sources to reduce monitoring. Key UCMR 5 PWS proposal requirements: n Site map indicating both, all well locations and proposed representative wells n Uniform Contamination susceptibility among the represented wells and representative well n Historical ground water quality data showing similarity among represented/representative well(s). All wells have either same treatment or no treatment Applications by PWSs must be submitted 6 months prior to scheduled collection and PWSs with multiple EPTDSs can propose sampling at representative locations, as opposed to sampling at each EPTDS. PWSs can reuse prior UCMR GWRMPs if there are no significant changes in EPTDSs configurations. If amendments to former plan must be done, amendment request must be made. See Table 2: GWRMP program key dates for PWSs.8 Representative sampling from wholesaler connections is an option for PWSs that purchase water with multiple connections from the same wholesaler to reduce monitoring.8 7. UCMR 5 Sampling Requirements: Frequency and Location PWSs will follow traditional UCMR sampling protocol, where samples will be collected at entry points to the distribution system (EPTDS) for all UCMR 5 contaminants.8 See Table 2 for outline: Table 2: UCMR 5 Sampling Requirements for Frequency and Location. UCMR 5 Sampling Requirements - Frequency and Location Water Source Timeframe Frequency Surface water, ground water under the direct influence of surface water, or mixed sources systems Year-round Systems must monitor 4 times during a consecutive 12-month monitoring period. Sample events must occur 3 months apart Ground water systems Year-round Systems must monitor 2 times during a consecutive 12-month monitoring period. Sample events must occur 5-7 months apart - PWSs will follow traditional UCMR sampling protocol - Samples to be collected at entry points to the distribution systems (EPTDS) for all UCMR 5 contaminants 8. SDWARS 5 and CDX: Reporting The Safe Drinking Water Accession and Reporting System (SDWARS 5) is used by both UCMR 5 PWSs and Approved Table 3: Targeted Contaminants and Methods. Organics – 29 PFAS Compounds EPA Method 537.1 Solid Phase Extraction (SPE) Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) EPA Method 537.1 Solid Phase Extraction (SPE) Liquid ChromatographyTandem Mass Spectrometry (LC-MS/MS) PFBS0.003 PFDA0.003 NMeFOSAA0.006 NFDHA0.002 PFPeA0.003 PFHxA0.003 PFNA0.004 NEtFOSAA0.005 PFBA0.005 PFPeS0.004 PFHxS0.03 PFUnA0.002 11Cl-PF3OUdS0.005 PFEESA0.003 4:2 FTS0.003 PFHpA0.03 PFDoA0.003 9Cl-PF3ONS0.002 PFHpS0.003 6:2 FTS0.005 PFOA0.004 PFTA0.008 ADONA0.003 PFMPA0.004 8:2 FTS0.005 PFOS0.004 PFTrDA0.007 HFPO-DA(GenX)0.005 PFMBA0.003 - Unique to EPA Method 537.1 EPA groups the analytes common to Method 537.1 and 533 under 533 as recommended workflow - MRLs (min reporting limit) are in superscript in µg/L Labs for results reporting. The Central Data Exchange is a secure, internet-based electronic reporting system used to upload analytical reports.8 EPA is in the process of providing access to: n SDWARS and CDX user instructions n Training sessions by key stakeholders- labs, PWSs, and States PFAS Analytical Methods to Monitor Drinking Water The SDWA requires the EPA to use validated analytical methods to assess unidentified or newly detected PFAS chemicals and will update analytical methods to monitor additional PFAS. As new PFAS compounds of concern are identified, the EPA will procure certified reference standards that are essential for their quantitation in drinking water samples. Additionally, the EPA will evaluate analytical methods previously published for monitoring PFAS in drinking water, such as EPA Methods 533 and 537.1, to determine the efficacy of expanding the established target PFAS analyte list to include any emerging PFAS to support future drinking water monitoring programs.2 Robust methods for detection and quantification of PFAS are critical and help evaluate the effectiveness of different technologies for remediation. UCMR 5 requires the analysis of 29 PFAS compounds by validated EPA methods 533 and 537.1. See Table 3 for a list of targeted PFAS in drinking water. Metals EPA Method 200.7 Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) Alternate SM 3120 B or ASTM D1976-20 Lithium9 Mitigation of PFAS in Drinking Water Through Innovation and Environmental Justice www.perkinelmer.com 7 Optimization of PFAS Analytical Method 537.1 and Method 533 The EPA’s priority to update their analytical methods for PFAS, has encouraged companies like to PerkinElmer to validate and optimize Method 537.1, specific to the analysis of PFAS in drinking water, and Method 533, a more inclusive method aimed at monitoring multiple short-chain PFAS that are difficult to measure by Method 537.1. In PerkinElmer’s (PerkinElmer) Method 537.1 and 533 application notes, specialists not only validated the method, but significantly improved the methodology using the PerkinElmer QSight® LX50 ultra high-performance liquid chromatography (UHPLC) system coupled with the PerkinElmer QSight 220 triple quadrupole mass spectrometer. Mitigate PFAS Background Contamination A major challenge with analyzing trace quantities of PFAS is the contamination of blanks, samples and QC samples stemming from the materials used in reagents, SPE apparatus, sample collection materials, volumetric ware, vials, the LC/MS system, and the lab environment. Customized solutions are required to remediate an LC/MS/MS system of PFAS background contamination.9,10 These key remediation steps include: n A delay column was placed between the mobile phase mixer in the pump and the sample valve in the autosampler to trap and delay any PFAS compounds arising from the pump and mobile phase solvents. 9,10 n The standard LX50 autosampler also contains PTFE tubing both internally and to the wash solution reservoirs that contribute to PFAS contamination. This contamination was remediated by replacing all PTFE tubing in the autosampler with PEEK tubing.9,10 Optimized Runtimes In addition to PFAS background contamination remediation, PerkinElmer’s application notes focused on the optimization of chromatographic methods described in EPA 537.1 and 533. 9,10 n Optimization of EPA Method 537.1 The original EPA chromatographic method had a 37-minute runtime, while the method developed by PerkinElmer reduced the injectionto-injection run time to 10 minutes. The total ion chromatogram (TIC) for PerkinElmer 537.1 application note is shown in Figure 5.9 Figure 5: Total ion chromatogram of an 80 ng/L extracted LFB sample containing all method analytes, surrogates and internal standards. Analyte Peak # RT (min) IS# Ref PFBS 1 3.54 2 PFHxA 2 4.15 1 HFPO-DA 4 4.34 1 PFHpA 6 4.78 1 PFHxS 7 4.77 2 ADONA 8 4.84 1 PFOA 9 5.30 1 PFOS 11 5.73 2 PFNA 13 5.74 1 9CI-PF3ONS 14 5.93 2 PFDA 15 6.13 1 NMeFOSAA 17 6.31 3 PFUnA 19 6.45 1 NEtFOSAA 20 6.47 3 11 CI-PF3OUdS 22 6.56 2 PFDoA 23 6.72 1 PFTrDA 24 6.96 1 PDTA 25 7.16 1 13C2-PFHxA SS#1 3 4.15 1 13C3-HFPO-DA SS#2 5 4.34 1 13C2-PFDA SS#3 16 6.12 1 d5-NEtFOSAA SS#4 21 6.46 3 13C2-PFOA IS#1 10 5.29 - 13C4-PFOS IS#2 12 5.74 - d3- NMeFOSAA IS#3 18 6.30 - Mitigation of PFAS in Drinking Water Through Innovation and Environmental Justice www.perkinelmer.com 8 n For EPA 533 The original EPA chromatographic method had a 35-minute runtime, while the method developed by PerkinElmer reduced the injectionto-injection run time to 10 minutes. The total ion chromatogram (TIC) for PerkinElmer 533 application note is shown in Figure 6.10 Figure 6: Total ion chromatogram of an 80 ng/L extracted LFB sample containing all method analytes and standards. PFAS Analytical Method 1633 Method 1633 is a part of the Clean Water Act (CWA) and is created to determine aqueous, solid (including soil, biosolids, and sediment) and tissue samples using liquid chromatography/mass spectrometry (LC-MS/MS). This method functions to quantify and calibrate PFAS analytes using isotopically labeled standards. While this is not a method required in UCMR 5, this is a significant method for PFAS analysis in non-potable matrices. The Future of PFAS There are currently over 7000 PFAS related compounds to date and many more derivative PFAS compounds are expected to be created in future development. The large scale of PFAS products will require careful analysis and review as more is discovered. Important highlights for the future outlook of PFAS include: Final Toxicity Assessments for GenX and Additional PFAS The EPA has stated that it will publish the toxicity assessments for two PFAS, hexafluoropropylene oxide dimer acid and its ammonium salt, also referred to as GenX chemicals. GenX chemicals are considered extremely prevalent in drinking water and have known impacts on human health, including reproductive and immunological toxicities, and the environment. The goal of the toxicity assessment for GenX is to continue to develop a robust understanding of how these additional PFAS impacts health and the environment. In additional to the GenX PFAS, the Office of Research and Development is also developing toxicity assessments for five other PFAS including PFBA, PFHxA, PFHxS, PFNA, and PFDA.2 Targeted and Non-Targeted Method Development EPA is planning to develop additional targeted methods for detecting and measuring specific PFAS and non-targeted methods for identifying unknown PFAS in the environment.2 Mitigation of PFAS in Drinking Water Through Innovation and Environmental Justice www.perkinelmer.com 9 Total PFAS Method Development Additional method development will be utilized for total PFAS methods that measure the amount of PFAS in environmental samples without identifying specific PFAS.2 The total PFAS method development timeline is outlined as follows: n Create a total adsorbable fluorine method for wastewater for potential laboratory validation (Fall 2021) n Develop a method for measuring additional PFAS in air emissions (Fall 2022) n Draft methods and approaches for evaluating PFAS leaching from solid materials (Fall 2022) Identifying PFAS Categories Part of the difficulty in gathering information on PFAS is because they are such a large and diverse class of compounds. In response to the large number of PFAS currently in use, the EPA is planning on classifying the PFAS compounds into smaller categories. These categories will be based on parameters such as chemical structure, physical and chemical properties, and toxicological properties.2 The EPA has outlined two approaches to categorize PFAS: 1. Utilize toxicity and toxicokinetic data to develop PFAS categories for further hazard assessment and to inform hazard or risk-based decisions. 2. Develop PFAS categories based on removal technologies using existing understanding of treatment, remediation, destruction, disposal, control, and mitigation principles. These approaches will function to identify missing elements in the EPA’s understanding of PFAS from hazard assessments and removal technology perspectives, further assisting the EPA’s prioritizing for future actions. Additionally, the EPA is going to develop a PFAS categorization database that will capture key characteristics of individual PFAS, including category assignments.2 Conclusion As the future of PFAS testing moves towards expanding PFAS toxicity assessments, optimizing methods, and identifying additional PFAS categories, it will be even more critical that researchers develop innovations within method development for enhanced PFAS analysis. Overcoming PFAS analytical challenges is critical for a comprehensive understanding of PFAS toxicities and environmental impacts. Properly developed and validated methods, such as those demonstrated by PerkinElmer, offer the increased throughput, contamination mitigation, and reduced runtimes necessary to overcome these challenges. The threat of PFAS contamination is a global concern, thus, it is paramount that the combined efforts of regulatory authorities, analytical technology manufacturers and water treatment facilities continue to develop the necessary legislation and innovations to facilitate necessary PFAS research and mitigation. PerkinElmer, Inc. 940 Winter Street Waltham, MA 02451 USA P: (800) 762-4000 or (+1) 203-925-4602 www.perkinelmer.com Mitigation of PFAS in Drinking Water Through Innovation and Environmental Justice References 1. US EPA. “EPA's PFAS Action Plan: A Summary of Key Actions”. https://www.epa.gov/sites/default/files/2019- 02/documents/pfas_action_factsheet_021319_ final_508compliant.pdf#:~:text=EPA%E2%80%99s%20 PFAS%20Action%20Plan%20outlines%20concrete%20 steps%20the,solutions%20and%20long-termstrategies%20 to%20address%20this%20important%20issue. 2. US EPA. “PFAS Strategic Roadmap: EPA’s Commitments to Action 2021—2024”. October 2021, https://www.epa.gov/ system/files/documents/2021-10/pfas-roadmap_final-508. pdf. 3. US EPA. “Safe Drinking Water Information”. 14 July 2015, www.epa.gov/ground-water-and-drinking-water/safedrinking-water-information. 4. US EPA. “Ground Water and Drinking Water”. 25 June 2019, www.epa.gov/ground-water-and-drinking-water. 5. US EPA, OW. “Monitoring Unregulated Contaminants in Drinking Water”. www.epa.gov, 3 Aug. 2015, www.epa.gov/ dwucmr. 6. US EPA, OW. “Reporting Requirements for the Unregulated Contaminant Monitoring Rule UCMR 5”. www.epa.gov, 1 Sept. 2015, www.epa.gov/dwucmr/reporting-requirementsunregulated-contaminant-monitoring-rule-ucmr-5. 7. US EPA. “Laboratory Approval Program for the Unregulated Contaminant Monitoring Rule (UCMR 5)”. www.epa.gov, 1 Sept. 2015, www.epa.gov/dwucmr/laboratory-approvalprogram-unregulated-contaminant-monitoring-rule-ucmr-5. 8. US EPA. “The Fifth Unregulated Contaminant Monitoring Rule (UCMR 5) Program Overview Fact Sheet”. https:// www.epa.gov/system/files/documents/2022-02/ucmr5- factsheet.pdf 9. Weisenseel J., Costanzo M., “Analysis of Perfluoroalkyl and Polyfluoroalkyl Substances in Drinking Water: Validation Studies of EPA Method 537.1 Using the QSight 220 UHPLC/ MS/MS”. https://resources.perkinelmer.com/labsolutions/ resources/docs/app-analysis-of-perfluoroalkylandperfluoroalkyl-substances-in-drinking-water-325319. pdf?ga=2.214986000.688478994.1647934962- 771738426.1635237554. 10. Belunis A., LaCourse W., Costanzo M., Weisenseel J., “Improved Throughput for the Analysis of Perfluoroalkyl and Polyfluoroalkyl Substances in Drinking Water by EPA Method 533”. https://www.perkinelmer.com/libraries/appimproved-throughput-for-the-analysis-of-perfluoroalkyl For a complete listing of our global offices, visit www.perkinelmer.com/ContactUs Copyright ©2022, PerkinElmer, Inc. All rights reserved. PerkinElmer® is a registered trademark of PerkinElmer, Inc. All other trademarks are the property of their respective owners. 868100 PKI