No health-based violations on EPA record since 2016.
Serves about 7,326 people (2,119 connections) with groundwater from its own wells.
From EPA's record for MA1341000. PurityMap is independent of Williamstown Water Dept.
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No health-based violations in the last 10 years, from EPA's SDWIS compliance database.
EPA required this system to test for 30 unregulated and emerging contaminants, from March 2025 to November 2025.
| Contaminant | Result | Limit | Status | Sampled | Source |
|---|---|---|---|---|---|
| 11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-03-18 to 2025-11-12 | UCMR5 Analytical Results: WILLIAMSTOWN WATER DEPT (MA1341000) |
| 1H, 1H, 2H, 2H-perfluorodecane sulfonic acid (8:2 FTS) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-03-18 to 2025-11-12 | UCMR5 Analytical Results: WILLIAMSTOWN WATER DEPT (MA1341000) |
| 1H, 1H, 2H, 2H-perfluorohexane sulfonic acid (4:2 FTS) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-03-18 to 2025-11-12 | UCMR5 Analytical Results: WILLIAMSTOWN WATER DEPT (MA1341000) |
| 1H, 1H, 2H, 2H-perfluorooctane sulfonic acid (6:2 FTS) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-03-18 to 2025-11-12 | UCMR5 Analytical Results: WILLIAMSTOWN WATER DEPT (MA1341000) |
| 4,8-Dioxa-3H-perfluorononanoic acid (ADONA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-03-18 to 2025-11-12 | UCMR5 Analytical Results: WILLIAMSTOWN WATER DEPT (MA1341000) |
| 9-Chlorohexadecafluoro-3-oxanone-1-sulfonic acid (9Cl-PF3ONS) | < 2 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-03-18 to 2025-11-12 | UCMR5 Analytical Results: WILLIAMSTOWN WATER DEPT (MA1341000) |
| Hexafluoropropylene oxide dimer acid (HFPO-DA) (GenX chemicals) | < 5 ng/L | 10 ng/L federal MCL (2024) | Not detected above the reporting limit | 2025-03-18 to 2025-11-12 | UCMR5 Analytical Results: WILLIAMSTOWN WATER DEPT (MA1341000) |
| Lithium | < 9 µg/L | 10 µg/L EPA health reference level (screening, not a legal limit)Screening level, not a legal limit | Not detected above the reporting limit | 2025-03-18 to 2025-09-23 | UCMR5 Analytical Results: WILLIAMSTOWN WATER DEPT (MA1341000) |
| N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-03-18 to 2025-11-12 | UCMR5 Analytical Results: WILLIAMSTOWN WATER DEPT (MA1341000) |
| N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA) | < 6 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-03-18 to 2025-11-12 | UCMR5 Analytical Results: WILLIAMSTOWN WATER DEPT (MA1341000) |
| Nonafluoro-3,6-dioxaheptanoic acid (NFDHA) | < 20 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-03-18 to 2025-11-12 | UCMR5 Analytical Results: WILLIAMSTOWN WATER DEPT (MA1341000) |
| Perfluoro (2-ethoxyethane) sulfonic acid (PFEESA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-03-18 to 2025-11-12 | UCMR5 Analytical Results: WILLIAMSTOWN WATER DEPT (MA1341000) |
| Perfluoro-3-methoxypropanoic acid (PFMPA) | < 4 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-03-18 to 2025-11-12 | UCMR5 Analytical Results: WILLIAMSTOWN WATER DEPT (MA1341000) |
| Perfluoro-4-methoxybutanoic acid (PFMBA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-03-18 to 2025-11-12 | UCMR5 Analytical Results: WILLIAMSTOWN WATER DEPT (MA1341000) |
| Perfluorobutanesulfonic acid (PFBS) | < 3 ng/L | 2,000 ng/L EPA health advisory (screening, not a legal limit)Screening level, not a legal limit | Not detected above the reporting limit | 2025-03-18 to 2025-11-12 | UCMR5 Analytical Results: WILLIAMSTOWN WATER DEPT (MA1341000) |
| Perfluorobutanoic acid (PFBA) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-03-18 to 2025-11-12 | UCMR5 Analytical Results: WILLIAMSTOWN WATER DEPT (MA1341000) |
| Perfluorodecanoic acid (PFDA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-03-18 to 2025-11-12 | UCMR5 Analytical Results: WILLIAMSTOWN WATER DEPT (MA1341000) |
| Perfluorododecanoic acid (PFDoA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-03-18 to 2025-11-12 | UCMR5 Analytical Results: WILLIAMSTOWN WATER DEPT (MA1341000) |
| Perfluoroheptanesulfonic acid (PFHpS) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-03-18 to 2025-11-12 | UCMR5 Analytical Results: WILLIAMSTOWN WATER DEPT (MA1341000) |
| Perfluoroheptanoic acid (PFHpA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-03-18 to 2025-11-12 | UCMR5 Analytical Results: WILLIAMSTOWN WATER DEPT (MA1341000) |
| Perfluorohexanesulfonic acid (PFHxS) | < 3 ng/L | 10 ng/L federal MCL (2024) | Not detected above the reporting limit | 2025-03-18 to 2025-11-12 | UCMR5 Analytical Results: WILLIAMSTOWN WATER DEPT (MA1341000) |
| Perfluorohexanoic acid (PFHxA) | < 3 ng/L | 400,000 ng/L Michigan EGLE state MCL (strictest US state) | Not detected above the reporting limit | 2025-03-18 to 2025-11-12 | UCMR5 Analytical Results: WILLIAMSTOWN WATER DEPT (MA1341000) |
| Perfluorononanoic acid (PFNA) | < 4 ng/L | 10 ng/L federal MCL (2024) | Not detected above the reporting limit | 2025-03-18 to 2025-11-12 | UCMR5 Analytical Results: WILLIAMSTOWN WATER DEPT (MA1341000) |
| Perfluorooctanesulfonic acid (PFOS) | < 4 ng/L | 4.0 ng/L federal MCL (2024) | Not detected above the reporting limit | 2025-03-18 to 2025-11-12 | UCMR5 Analytical Results: WILLIAMSTOWN WATER DEPT (MA1341000) |
| Perfluorooctanoic acid (PFOA) | < 4 ng/L | 4.0 ng/L federal MCL (2024) | Not detected above the reporting limit | 2025-03-18 to 2025-11-12 | UCMR5 Analytical Results: WILLIAMSTOWN WATER DEPT (MA1341000) |
| Perfluoropentanesulfonic acid (PFPeS) | < 4 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-03-18 to 2025-11-12 | UCMR5 Analytical Results: WILLIAMSTOWN WATER DEPT (MA1341000) |
| Perfluoropentanoic acid (PFPeA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-03-18 to 2025-11-12 | UCMR5 Analytical Results: WILLIAMSTOWN WATER DEPT (MA1341000) |
| Perfluorotetradecanoic acid (PFTA) | < 8 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-03-18 to 2025-11-12 | UCMR5 Analytical Results: WILLIAMSTOWN WATER DEPT (MA1341000) |
| Perfluorotridecanoic acid (PFTrDA) | < 7 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-03-18 to 2025-11-12 | UCMR5 Analytical Results: WILLIAMSTOWN WATER DEPT (MA1341000) |
| Perfluoroundecanoic acid (PFUnA) | < 2 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2025-03-18 to 2025-11-12 | UCMR5 Analytical Results: WILLIAMSTOWN WATER DEPT (MA1341000) |
Screening tells you if something is worth a closer look; a lab result is the number you can act on.
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Screening: quick check, not lab-grade
Safe Home (EnviroTestKits)
Lead, read as one of three ranges: 0–4, 5–15 or 15+ ppb
Turnaround: 5 minutes
What it can't tell you: It shows a lead range, not an exact level, and tests nothing else unless you pay extra for the optional lab test.
Lab-certified results
ETR Laboratories
50+ substances, including lead, copper, arsenic, nitrate, hardness and coliform bacteria
Environmental Testing and Research Laboratories (ETR Labs), Leominster, MA · ISO/IEC 17025:2017, ANAB certificate AT-2638 · 2–4 business days after the lab receives it
What it can't tell you: It does not test PFAS, and not every result on the panel falls under the lab's accredited scope.
Get PurityMap updates about this water system.
Follow this water →Williamstown Water Dept's phone number on EPA record is 4134583383. Its mailing address is 675 SIMONDS RD, WILLIAMSTOWN, MA 01267.
According to EPA's record, Williamstown Water Dept uses groundwater from its own wells.
No health-based violations on EPA record since 2016. The record comes from EPA's SDWIS compliance database.
Lead was not detected at the 90th percentile of tap samples in Williamstown Water Dept's latest lead and copper round, which ended in December 2021. The federal action level is 15 µg/L.
PurityMap has no verified website for Williamstown Water Dept. Its phone number on EPA record is 4134583383. Its mailing address on EPA record is 675 SIMONDS RD, WILLIAMSTOWN, MA 01267. Your water bill lists the ways to contact your supplier and pay. PurityMap does not take payments.