Community Water System · PWS MA2002000
Acton Water Supply District
Operator location Acton, Massachusetts - UCMR5 detected 8 PFAS compounds (upper-third PFAS panel (> 4 compounds)) on this PWS; SDWIS lists 174 violations and 20,780 people served.
- 20,780
- People served (this PWS)
- 174
- EPA violations (this PWS)
- 37
- Health-based (this PWS)
- 8 PFAS
- UCMR5 (this PWS)
Acton Water Supply District standing, high SDWIS violation third
UCMR5 detected 8 PFAS compounds - upper-third PFAS panel (> 4 compounds). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 21% is middle-third health share (≤ 23%). UCMR5: upper-third PFAS panel (> 4 compounds). Population rank #2,629 of 29,740 among systems serving 500+.
The verdict
Acton Water Supply District sits in the upper third of the sitemap cohort by violation count (174), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is large (20,780; larger served population (> 3,309)), so household exposure scale sits behind the violation mix. Health-based share is 21% (middle-third health share (≤ 23%)). UCMR5 detected 8 PFAS compounds (upper-third PFAS panel (> 4 compounds)).
- #2,629 of 29,740
- Population · /systems
- #111 of 418
- Population · MA
- 174
- Total EPA violations on record
- 21%
- Health-based (MCL / treatment failure)
Population ordinals match the sitemap cohort (systems serving 500+, population_served DESC). See methodology · corpus placement.
8 PFAS "forever chemicals" detected in testing under EPA's UCMR5 monitoring program.
System Details
- System Type
- Community
- Owner Type
- Local
- Connections
- 6,896
- County
- Middlesex
- School/Daycare
- No
- MCL Violations
- 37
- Monitoring Violations
- 121
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Coliform (TCR) | MCL | 37 | 2014 |
| 1,1,2-Trichloroethane | MR | 5 | 2023 |
| Benzene | MR | 5 | 2023 |
| 1,2-Dichloroethane | MR | 5 | 2023 |
| Trichloroethylene | MR | 5 | 2023 |
| 1,1,1-Trichloroethane | MR | 5 | 2023 |
| Vinyl chloride | MR | 5 | 2023 |
| CHLOROBENZENE | MR | 5 | 2023 |
| 1,2-Dichloropropane | MR | 5 | 2023 |
| Ethylbenzene | MR | 5 | 2023 |
| Styrene | MR | 5 | 2023 |
| Tetrachloroethylene | MR | 5 | 2023 |
| Toluene | MR | 5 | 2023 |
| Xylenes, Total | MR | 5 | 2023 |
| 1,2,4-Trichlorobenzene | MR | 5 | 2023 |
| Carbon tetrachloride | MR | 5 | 2023 |
| 1,1-Dichloroethylene | MR | 5 | 2023 |
| o-Dichlorobenzene | MR | 5 | 2023 |
| trans-1,2-Dichloroethylene | MR | 5 | 2023 |
| cis-1,2-Dichloroethylene | MR | 5 | 2023 |
| DICHLOROMETHANE | MR | 5 | 2023 |
| p-Dichlorobenzene | MR | 5 | 2023 |
| Nitrate | MR | 3 | 1994 |
| Coliform (TCR) | MR | 3 | 2009 |
| ETHYLENE DIBROMIDE | MR | 2 | 2023 |
| 1,2-DIBROMO-3-CHLOROPROPANE | MR | 2 | 2023 |
| Revised Total Coliform Rule | MON | 2 | 2024 |
| Surface Water Treatment Rule | MR | 2 | 2014 |
| Fluoride | MR | 1 | 2006 |
| Nitrite | MR | 1 | 1993 |
Violation Count vs. the National Corpus
Acton Water Supply District has 174 recorded EPA violations, 83% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 17% carry more. 21% of this system's own violations are health-based (37 of 174), and it ranks #2,629 of 29,740 by population served among that same cohort.
EPA violations vs. the national water-system corpus
Public water systems serving 500+ people (EPA SDWIS)
174 Higher than most more violations than 83% of 29,740 water systems
the national water-system corpus, bucketed by value
Each bar is a band; taller bars hold more water systems. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source EPA SDWIS · 2026-05-15
PFAS Testing Results (UCMR5)
Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 47 of 290 samples detected PFAS.
| Contaminant | Date | Result | MRL | Status |
|---|---|---|---|---|
| PFHxA | 9/25/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFDoA | 9/25/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFDA | 9/25/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFOA | 9/25/2023 | 4.70 ppt | 4.00 ppt | Detected |
| PFOS | 9/25/2023 | 4.20 ppt | 4.00 ppt | Detected |
| PFNA | 9/25/2023 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFHxS | 9/25/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHpA | 9/25/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFUnA | 9/25/2023 | <2.00 ppt | 2.00 ppt | Not Detected |
| PFTrDA | 9/25/2023 | <7.00 ppt | 7.00 ppt | Not Detected |
| PFBS | 9/25/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| NMeFOSAA | 9/25/2023 | <6.00 ppt | 6.00 ppt | Not Detected |
| NEtFOSAA | 9/25/2023 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFTA | 9/25/2023 | <8.00 ppt | 8.00 ppt | Not Detected |
| PFMBA | 9/25/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| 11Cl-PF3OUdS | 9/25/2023 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFHpS | 9/25/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFPeS | 9/25/2023 | <4.00 ppt | 4.00 ppt | Not Detected |
| NFDHA | 9/25/2023 | <20.00 ppt | 20.00 ppt | Not Detected |
| PFEESA | 9/25/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFPeA | 9/25/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFMPA | 9/25/2023 | <4.00 ppt | 4.00 ppt | Not Detected |
| 8:2 FTS | 9/25/2023 | <5.00 ppt | 5.00 ppt | Not Detected |
| 4:2 FTS | 9/25/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| 6:2 FTS | 9/25/2023 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFBA | 9/25/2023 | <5.00 ppt | 5.00 ppt | Not Detected |
| HFPO-DA | 9/25/2023 | <5.00 ppt | 5.00 ppt | Not Detected |
| ADONA | 9/25/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| 9Cl-PF3ONS | 9/25/2023 | <2.00 ppt | 2.00 ppt | Not Detected |
| PFOS | 9/21/2023 | <4.00 ppt | 4.00 ppt | Not Detected |
| 9Cl-PF3ONS | 9/21/2023 | <2.00 ppt | 2.00 ppt | Not Detected |
| 11Cl-PF3OUdS | 9/21/2023 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFUnA | 9/21/2023 | <2.00 ppt | 2.00 ppt | Not Detected |
| PFHxA | 9/21/2023 | 5.40 ppt | 3.00 ppt | Detected |
| PFDoA | 9/21/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFMBA | 9/21/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFOA | 9/21/2023 | 11.90 ppt | 4.00 ppt | Detected |
| PFNA | 9/21/2023 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFHxS | 9/21/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFBS | 9/21/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHpS | 9/21/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFPeS | 9/21/2023 | <4.00 ppt | 4.00 ppt | Not Detected |
| NFDHA | 9/21/2023 | <20.00 ppt | 20.00 ppt | Not Detected |
| PFDA | 9/21/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| ADONA | 9/21/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHpA | 9/21/2023 | 4.80 ppt | 3.00 ppt | Detected |
| PFPeA | 9/21/2023 | 4.60 ppt | 3.00 ppt | Detected |
| HFPO-DA | 9/21/2023 | <5.00 ppt | 5.00 ppt | Not Detected |
| 6:2 FTS | 9/21/2023 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFMPA | 9/21/2023 | <4.00 ppt | 4.00 ppt | Not Detected |
UCMR5 PFAS record for Acton Water Supply District
Open EPA SDWIS federal reports for PWS MA2002000 to cross-check UCMR5 detections and violation codes; state primacy agencies enforce the Safe Drinking Water Act locally.
Sources: EPA SDWIS · MassDEP, Drinking Water Program
Nationwide peers
174 violations · 20,780 served: nearest cross-state SDWIS matches.
Cross-state systems with comparable violation load
Nearest cross-state community systems (500+ served) by total SDWIS violations on record.
Cross-state systems with similar served population
Nearest cross-state systems by EPA SDWIS population_served (same 500+ sitemap gate).
What to do with Acton Water Supply District
Use this system's EPA-reported record as a starting filter, not a final verdict.
- See how every tracked system in Massachusetts compares on the same EPA violation measures. Massachusetts systems
- Check whether PFAS was detected at this system under UCMR5 testing. PFAS guide
- Find and compare another public water system by name or PWSID. Search systems
EPA SDWIS and UCMR5 figures are informational only, not a substitute for a certified lab test of your own tap water.