What is the Unregulated Contaminant Monitoring Rule (UCMR)?
In accordance with provisions in the Safe Drinking Water Act (SDWA), public water suppliers are required to monitor for up to 30 unregulated contaminants on a five-year cycle. Unregulated contaminants are those that don’t yet have a drinking water standard set by the United States Environmental Protection Agency (EPA). Monitoring for these contaminants helps EPA determine the contaminant’s occurrence and whether future regulation is warranted to protect public health. During 2023 and early 2024, th District monitored for 30 contaminants at our treatment facilities as part of the UCMR 5 program. These contaminants included 29 Per- and Polyfluoroalkyl substances (PFAS) and lithium.
Why are PFAS being monitored for as part of UCMR 5 if they are already regulated in Massachusetts?
The National Defense Authorization Act for Fiscal Year 2020 (NDAA) specifies that EPA shall include all PFAS in UCMR 5 for which a drinking water method has been validated and that are not subject to a National Primary Drinking Water Regulation (NPDWR). Accordingly, UCMR 5 includes all 29 PFAS that are within the scope of EPA Methods 533 and 537.1.
While the Massachusetts Department of Environmental Protection (MassDEP) established a Maximum Contaminant Level (MCL) of 20 parts per trillion (ppt) for the sum of six PFAS compounds (PFAS6) in October 2020, this standard applies only to water suppliers in Massachusetts. Because UCMR 5 is a national program and PFAS were not regulated on a national scale at the time the rule was finalized, they are included in the monitoring. Notably, EPA later proposed a NPDWR for PFAS in March 2023 that is expected to be finalized in early 2024.
What were the results of the District’s UCMR 5 sampling?
All the results of the 2023-2024 monitoring are presented in the charts below. Four unregulated PFAS were detected during the monitoring. PFAS6, which is regulated and treated as a single contaminant in Massachusetts, was also detected. Lithium was not detected in any of the samples.
The results for the samples collected in 2023 will also be presented in the District’s 2023 Annual Water Quality Report that will be published by July 1, 2024.
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2023 & 2024 UCMR5 Results - Unregulated Contaminants |
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Substance |
Units |
Range of Detects |
Average Detected |
Level Allowed (MCL) |
Typical Source |
|
Perfluorobutanoic acid (PFBA) |
ppt |
ND - 11.8 |
16.2 |
N/A |
Breakdown product of other PFAS that are used in stain-resistant fabrics, paper food packaging, and carpets; also historically used for manufacturing photographic film |
|
Perfluorobutanesulfonic acid (PFBS) |
ppt |
ND - 3.7 |
3.4 |
N/A |
Manmade chemical; used as a replacement for PFOS; used in the manufacture of paints, cleaning agents, and water- and stain-repellent products and coatings, including carpeting, carpet cleaners, floor wax and food packaging |
|
Perfluoropentanoic acid (PFPeA) |
ppt |
ND - 8.4 |
5.9 |
N/A |
Manmade chemical; used in products to make them stain, grease, heat, and water resistant |
|
Perfluorohexanoic acid (PFHxA) |
ppt |
ND - 7.1 |
5.5 |
N/A |
Manmade chemical; breakdown product of stain- and grease-proof coatings on food packaging and household products |
|
Lithium |
ppb |
ND |
ND |
N/A |
Abundant element in the earth’s crust, present in certain minerals, especially in areas of volcanic activity and in fluids associated with gas and oil well drilling; anthropogenic sources of lithium include its use in batteries, ceramics, glass, lubricants, metallurgy, and medicine and so it may be found in leachate from landfills, septic systems, and sewage treatment plants. |
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*ND = Not Detected |
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| 2023 & 2024 UCMR5 Results - MassDEP Regulated Contaminants | |||||
|
Substance |
Units |
Range of Detects |
Average Detected |
Level Allowed (MCL) |
Typical Source |
| PFAS6 | ppt | 8.9 - 19.1 | 13.3 | 20 | Discharges and emissions from industrial and manufacturing sources associated with the production or use of these PFAS, including production of moisture and oil resistant coatings on fabrics and other materials. Additional sources include the use and disposal of products containing these PFAS, such as fire-fighting foams. |
Additional Resources
March 1, 2024 UCMR Data Availability Public Notice
https://www.epa.gov/dwucmr/learn-about-unregulated-contaminant-monitoring-rule
https://www.epa.gov/dwucmr/fifth-unregulated-contaminant-monitoring-rule
