UCMR5 – Testing for Lithium and PFAS (Per/Polyfluoroalkyl Substances)
The Safe Drinking Water Act requires the USEPA issue a list of potential contaminants to be added to the Safe Drinking Water Act. As a result, USEPA is including twenty-nine Per- and Polyfluoroalkyl Substances in the Fifth Unregulated Contaminant Monitoring (UCMR5) to evaluate if these compounds should be included in the Safe Drinking Water Act (SDWA), in addition to Lithium. This testing will reveal what compounds are found in our nation’s drinking water supplies, at what levels, and determine if they become part of the SDWA monitoring requirements.
Between 2023 and 2025 sample collection and analysis at all entry points for community systems that serve a population greater than 3,300 will be required. 800 randomly selected systems under 3,300 will also be required to monitor. Visit USEPA’s website for more information.
- Drinking Water PFAS Testing
- Non-Potable Water, Wastewater, Groundwater PFAS Testing
- What is PFAS? A History.
EPA 533 UCMR5 Contaminant List3
| Contaminant | CAS Number | MRL |
| 11-chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS) | 763051-92-9 | 0.005 µg/L |
| 9-chlorohexadecafluoro-3-oxanonane-1-sulfonic acid (9Cl-PF3ONS) | 756426-58-1 | 0.002 µg/L |
| 4,8-dioxa-3H-perfluorononanoic acid (ADONA)2 | 919005-14-4 | 0.003 µg/L |
| hexafluoropropylene oxide dimer acid (HFPO‑DA) | 13252-13-6 | 0.005 µg/L |
| nonafluoro-3,6-dioxaheptanoic acid (NFDHA) | 151772-58-6 | 0.02 µg/L |
| perfluorobutanoic acid (PFBA) | 375-22-4 | 0.005 µg/L |
| perfluorobutanesulfonic acid (PFBS) | 375-73-5 | 0.003 µg/L |
| 1H,1H, 2H, 2H-perfluorodecane sulfonic acid (8:2FTS) | 39108-34-4 | 0.005 µg/L |
| perfluorodecanoic acid (PFDA) | 335-76-2 | 0.003 µg/L |
| perfluorododecanoic acid (PFDoA) | 307-55-1 | 0.003 µg/L |
| perfluoro(2-ethoxyethane)sulfonic acid (PFEESA) | 113507-82-7 | 0.003 µg/L |
| perfluoroheptanesulfonic acid (PFHpS) | 375-92-8 | 0.003 µg/L |
| perfluoroheptanoic acid (PFHpA) | 375-85-9 | 0.003 µg/L |
| 1H,1H, 2H, 2H-perfluorohexane sulfonic acid (4:2FTS) | 757124-72-4 | 0.003 µg/L |
| perfluorohexanesulfonic acid (PFHxS) | 355-46-4 | 0.003 µg/L |
| perfluorohexanoic acid (PFHxA) | 307-24-4 | 0.003 µg/L |
| perfluoro-3-methoxypropanoic acid (PFMPA) | 377-73-1 | 0.004 µg/L |
| perfluoro-4-methoxybutanoic acid (PFMBA) | 863090-89-5 | 0.003 µg/L |
| perfluorononanoic acid (PFNA) | 375-95-1 | 0.004 µg/L |
| 1H,1H, 2H, 2H-perfluorooctane sulfonic acid (6:2FTS) | 27619-97-2 | 0.005 µg/L |
| perfluorooctanesulfonic acid (PFOS) | 1763-23-1 | 0.004 µg/L |
| perfluorooctanoic acid (PFOA) | 335-67-1 | 0.004 µg/L |
| perfluoropentanoic acid (PFPeA) | 2706-90-3 | 0.003 µg/L |
| perfluoropentanesulfonic acid (PFPeS) | 2706-91-4 | 0.004 µg/L |
| Perfluoroundecanoic acid (PFUnA) | 2058-94-8 | 0.002 µg/L |
EPA 537.1 UCMR5 Contaminant List3
| Contaminant | CAS Number | MRL |
| N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA) | 2991-50-6 | 0.005 µg/L |
| N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA) | 2355-31-9 | 0.006 µg/L |
| perfluorotetradecanoic acid (PFTA) | 376-06-7 | 0.008 µg/L |
| perfluorotridecanoic acid (PFTrDA) | 72629-94-8 | 0.007 µg/L |