## 5 Governmental Environmental Regulatory Efforts
### The Environmental Protection Agency (EPA)  
The Environmental Protection Agency (EPA) of the United States released a comprehensive action plan in February of 2019 on PFAS in the environment [121; 122]. This action plan is designed to support the Safe Drinking Water Act (SDWA), which addresses PFAS in drinking water and outlines  
Figure 3: Removals exceeding 25% occurred in the enhanced coagulation region characterized by higher alum dosages (e.g., >60 mg/L) and (thus) lower coagulated water pH(4.5–6.5). Reproduced from [PERSON]; [PERSON]; [PERSON] Water Research 2013, 47 (1), 49–56 (reference 119). Reproduced with permission from [PERSON], Water Research; published by Elsevier 2013.  
measurement procedures for the amount of perfluorinated chemicals (PFCs) in water [23; 77]. The EPA's current methods for drinking water detection, Method 533 and 537.1, focus on carbon chain lengths of 4 to 12 within the PFAS category, and they follow the SDWA for PFOA and PFOS [53; 54]. These testing methods, which complement each other, allow for the measurement of 29 different chemicals, and the EPA is still working on obtaining more information to determine a definite limit of unsafe levels of PFAS for human health and aquatic life as well as the potential regulation of industrial wastewater [23; 77]. The current Lifetime Health Advisory standard for the amount of PFOS/PFOA in drinking water is 70 ppt as recommended by the EPA [105]. In December of 2019, the Interim Recommendations for Addressing Groundwater Contaminated with PFOA and PFOS was issued using a screening level of 40 ppt to determine if further attention is warranted [23]. The preliminary remediation goal of 70 ppt was set for contaminated ground water based on the Lifetime Drinking Water Health Advisory level [23]. Currently, the EPA is in the process of designating PFOA and PFOS as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) which would allow the government to tax manufacturers using these substances and use the money toward removing them from the environment [23; 78]. Similar to method 533 and 537.1 for determining PFAS in drinking water, the EPA has developed other methods for testing non-potable groundwater, surface water, and wastewater outlined as SW-846 Method 8327 [23; 75]. Guidance for destruction and disposal of PFAS using methods such as high temperature incineration is currently being developed but have not been formally established or published by the EPA [23].  
The primary methods used to detect PFASs in drinking water are Method 533 and 537.1, and SW-846 Method 8327 is used to test PFASs in groundwater, surface water, and wastewater [53; 54; 75]. All three of these methods utilize liquid chromatography/tandem mass spectrometry, but the differences in extraction provide the differences in compounds detected [53; 54; 75]. US EPA Method 533 was published in November of 2019, and consists of a solid phase extraction (SPE) (LC-MS/MS) while utilizing the Multiple Reaction Monitoring (MRM) mode of the MS/MS to enhance selectivity [53]. Method 533 focuses on short chain PFASs, those with 4 to 12 carbon chain length, and can measure 25 chemicals, 11 of which cannot be detected with Method 537.1 [123]. Methods 533 and 537.1 are designed to complement each other, with the two combined being able to detect 29 different PFASs [123]. US EPA Method 537.1 is an update to the original method, 537, which was published in 2008 and revised in 2015 [124]. Method 537.1 was published in November of 2018 and similarly uses SPE and LC-MS/MS as in Method 533 [54]. Method 537.1 detects a total of 18 PFASs with 4 that cannot be detected with Method 533 [54; 123]. Like Methods 533 and 537.1, Method 8327 uses LC-MS/MS but instead is designed to measure PFAS in groundwater, surface water, and wastewater as opposed to drinking water [75]. This method was published in June of 2019 and requires the MS to be in MRM mode [75].