Community Water System · PWS MA3056000
Chelmsford Water District
Operator location Chelmsford, Massachusetts - UCMR5 detected 5 PFAS compounds (upper-third PFAS panel (> 4 compounds)) on this PWS; SDWIS lists 12 violations and 28,750 people served.
- 28,750
- People served (this PWS)
- 12
- EPA violations (this PWS)
- 1
- Health-based (this PWS)
- 5 PFAS
- UCMR5 (this PWS)
Chelmsford Water District standing, low SDWIS violation third
UCMR5 detected 5 PFAS compounds - upper-third PFAS panel (> 4 compounds). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 8% is middle-third health share (≤ 23%). UCMR5: upper-third PFAS panel (> 4 compounds). Population rank #1,945 of 29,740 among systems serving 500+.
The verdict
Chelmsford Water District is in the lower third by violation count (12; lower-third violation load (≤ 21 violations)). A low count does not mean the system is unmonitored - monitoring and reporting violations still appear in SDWIS. Population served is large (28,750; larger served population (> 3,309)), so household exposure scale sits behind the violation mix. Health-based share is 8% (middle-third health share (≤ 23%)). UCMR5 detected 5 PFAS compounds (upper-third PFAS panel (> 4 compounds)).
- #1,945 of 29,740
- Population · /systems
- #83 of 418
- Population · MA
- 12
- Total EPA violations on record
- 8%
- Health-based (MCL / treatment failure)
Population ordinals match the sitemap cohort (systems serving 500+, population_served DESC). See methodology · corpus placement.
5 PFAS "forever chemicals" detected in testing under EPA's UCMR5 monitoring program.
System Details
- System Type
- Community
- Owner Type
- Local
- Connections
- 8,388
- County
- Middlesex
- School/Daycare
- No
- MCL Violations
- 1
- Monitoring Violations
- 4
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Coliform (TCR) | MR | 2 | 1994 |
| Consumer Confidence Rule | Other | 2 | 2014 |
| Nitrate | MR | 2 | 2013 |
| Coliform (TCR) | MCL | 1 | 1991 |
Violation Count vs. the National Corpus
Chelmsford Water District has 12 recorded EPA violations, 21% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 78% carry more. 8% of this system's own violations are health-based (1 of 12), and it ranks #1,945 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)
12 Among the lowest violation counts fewer violations than 78% 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. 25 of 232 samples detected PFAS.
| Contaminant | Date | Result | MRL | Status |
|---|---|---|---|---|
| 8:2 FTS | 5/14/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFPeS | 5/14/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFPeA | 5/14/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFMBA | 5/14/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFEESA | 5/14/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| NFDHA | 5/14/2024 | <20.00 ppt | 20.00 ppt | Not Detected |
| PFHpS | 5/14/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFNA | 5/14/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| 4:2 FTS | 5/14/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFOA | 5/14/2024 | 7.70 ppt | 4.00 ppt | Detected |
| PFMPA | 5/14/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFHpA | 5/14/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| 6:2 FTS | 5/14/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFOS | 5/14/2024 | 5.50 ppt | 4.00 ppt | Detected |
| PFBS | 5/14/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFDA | 5/14/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFDoA | 5/14/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHxA | 5/14/2024 | 3.10 ppt | 3.00 ppt | Detected |
| PFUnA | 5/14/2024 | <2.00 ppt | 2.00 ppt | Not Detected |
| 11Cl-PF3OUdS | 5/14/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| 9Cl-PF3ONS | 5/14/2024 | <2.00 ppt | 2.00 ppt | Not Detected |
| ADONA | 5/14/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| HFPO-DA | 5/14/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFBA | 5/14/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFHxS | 5/14/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFEESA | 4/9/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFPeA | 4/9/2024 | 3.20 ppt | 3.00 ppt | Detected |
| PFNA | 4/9/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFHxS | 4/9/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHpA | 4/9/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFBS | 4/9/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFMPA | 4/9/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFMBA | 4/9/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFDoA | 4/9/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| NFDHA | 4/9/2024 | <20.00 ppt | 20.00 ppt | Not Detected |
| PFPeS | 4/9/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| 8:2 FTS | 4/9/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFOS | 4/9/2024 | 4.50 ppt | 4.00 ppt | Detected |
| PFDA | 4/9/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHxA | 4/9/2024 | 3.20 ppt | 3.00 ppt | Detected |
| PFUnA | 4/9/2024 | <2.00 ppt | 2.00 ppt | Not Detected |
| 11Cl-PF3OUdS | 4/9/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| 9Cl-PF3ONS | 4/9/2024 | <2.00 ppt | 2.00 ppt | Not Detected |
| ADONA | 4/9/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| HFPO-DA | 4/9/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFBA | 4/9/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| 6:2 FTS | 4/9/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFTA | 4/9/2024 | <8.00 ppt | 8.00 ppt | Not Detected |
| PFOA | 4/9/2024 | 7.20 ppt | 4.00 ppt | Detected |
| PFHpS | 4/9/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
UCMR5 PFAS record for Chelmsford Water District
Open EPA SDWIS federal reports for PWS MA3056000 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
12 violations · 28,750 served: nearest cross-state SDWIS matches.
Cross-state systems with similarly light violation ledgers
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 Chelmsford Water 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.