Community Water System · PWS MA3180000
Merrimac Water Department
Operator location Merrimac, Massachusetts - UCMR5 detected 1 PFAS compound (lower-third PFAS panel (≤ 2 compounds)) on this PWS; SDWIS lists 276 violations and 7,193 people served.
- 7,193
- People served (this PWS)
- 276
- EPA violations (this PWS)
- 14
- Health-based (this PWS)
- 1 PFAS
- UCMR5 (this PWS)
Merrimac Water Department standing, high SDWIS violation third
UCMR5 detected 1 PFAS compound - lower-third PFAS panel (≤ 2 compounds). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 5% is middle-third health share (≤ 23%). UCMR5: lower-third PFAS panel (≤ 2 compounds). Population rank #6,031 of 29,740 among systems serving 500+.
The verdict
Merrimac Water Department sits in the upper third of the sitemap cohort by violation count (276), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is large (7,193; larger served population (> 3,309)), so household exposure scale sits behind the violation mix. Health-based share is 5% (middle-third health share (≤ 23%)). UCMR5 detected 1 PFAS compound (lower-third PFAS panel (≤ 2 compounds)).
- #6,031 of 29,740
- Population · /systems
- #206 of 418
- Population · MA
- 276
- Total EPA violations on record
- 5%
- Health-based (MCL / treatment failure)
Population ordinals match the sitemap cohort (systems serving 500+, population_served DESC). See methodology · corpus placement.
1 PFAS "forever chemicals" detected in testing under EPA's UCMR5 monitoring program.
System Details
- System Type
- Community
- Owner Type
- Local
- Connections
- 1,980
- County
- Essex
- School/Daycare
- No
- MCL Violations
- 8
- Monitoring Violations
- 249
- Treatment Tech Violations
- 6
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Coliform (TCR) | MCL | 8 | 2004 |
| Lead and Copper Rule | TT | 6 | 1997 |
| ETHYLENE DIBROMIDE | MR | 5 | 2019 |
| Pentachlorophenol | MR | 5 | 2019 |
| Toxaphene | MR | 5 | 2019 |
| 2,4,5-TP | MR | 5 | 2019 |
| Methoxychlor | MR | 5 | 2019 |
| BHC-GAMMA | MR | 5 | 2019 |
| 1,2-DIBROMO-3-CHLOROPROPANE | MR | 5 | 2019 |
| Diquat | MR | 5 | 2019 |
| Endothall | MR | 5 | 2019 |
| HEXACHLOROBENZENE | MR | 5 | 2019 |
| OXAMYL | MR | 5 | 2019 |
| Picloram | MR | 5 | 2019 |
| Simazine | MR | 5 | 2019 |
| Heptachlor epoxide | MR | 5 | 2019 |
| Heptachlor | MR | 5 | 2019 |
| Lead and Copper Rule | MR | 5 | 2021 |
| Total Polychlorinated Biphenyls (PCB) | MR | 5 | 2019 |
| Benzo(a)pyrene | MR | 5 | 2019 |
| Dalapon | MR | 5 | 2019 |
| Atrazine | MR | 5 | 2019 |
| Carbofuran | MR | 5 | 2019 |
| Endrin | MR | 5 | 2019 |
| Glyphosate | MR | 5 | 2019 |
| LASSO | MR | 5 | 2019 |
| Chlordane | MR | 5 | 2019 |
| 2,4-D | MR | 5 | 2019 |
| Dinoseb | MR | 5 | 2019 |
| 2,3,7,8-TCDD | MR | 5 | 2019 |
Violation Count vs. the National Corpus
Merrimac Water Department has 276 recorded EPA violations, 90% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 10% carry more. 5% of this system's own violations are health-based (14 of 276), and it ranks #6,031 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)
276 Higher than most more violations than 90% 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. 2 of 116 samples detected PFAS.
| Contaminant | Date | Result | MRL | Status |
|---|---|---|---|---|
| PFBA | 7/9/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| NFDHA | 7/9/2024 | <20.00 ppt | 20.00 ppt | Not Detected |
| ADONA | 7/9/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| NEtFOSAA | 7/9/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFPeS | 7/9/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFEESA | 7/9/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFMBA | 7/9/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFPeA | 7/9/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFTrDA | 7/9/2024 | <7.00 ppt | 7.00 ppt | Not Detected |
| PFTA | 7/9/2024 | <8.00 ppt | 8.00 ppt | Not Detected |
| PFMPA | 7/9/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| 8:2 FTS | 7/9/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| 4:2 FTS | 7/9/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| 6:2 FTS | 7/9/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| HFPO-DA | 7/9/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFHxS | 7/9/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHpS | 7/9/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| 9Cl-PF3ONS | 7/9/2024 | <2.00 ppt | 2.00 ppt | Not Detected |
| NMeFOSAA | 7/9/2024 | <6.00 ppt | 6.00 ppt | Not Detected |
| PFBS | 7/9/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHpA | 7/9/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFNA | 7/9/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFOS | 7/9/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFOA | 7/9/2024 | 5.60 ppt | 4.00 ppt | Detected |
| PFDA | 7/9/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFDoA | 7/9/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHxA | 7/9/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFUnA | 7/9/2024 | <2.00 ppt | 2.00 ppt | Not Detected |
| 11Cl-PF3OUdS | 7/9/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| 4:2 FTS | 7/9/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHxS | 7/9/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFNA | 7/9/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFOS | 7/9/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFOA | 7/9/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFDA | 7/9/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFDoA | 7/9/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHxA | 7/9/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFUnA | 7/9/2024 | <2.00 ppt | 2.00 ppt | Not Detected |
| 11Cl-PF3OUdS | 7/9/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| 9Cl-PF3ONS | 7/9/2024 | <2.00 ppt | 2.00 ppt | Not Detected |
| ADONA | 7/9/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| HFPO-DA | 7/9/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| NMeFOSAA | 7/9/2024 | <6.00 ppt | 6.00 ppt | Not Detected |
| 6:2 FTS | 7/9/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFBS | 7/9/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| 8:2 FTS | 7/9/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFMPA | 7/9/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFPeA | 7/9/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFMBA | 7/9/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFEESA | 7/9/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
UCMR5 PFAS record for Merrimac Water Department
Open EPA SDWIS federal reports for PWS MA3180000 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
276 violations · 7,193 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 Merrimac Water Department
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.