Community Water System · PWS CT0340011
Danbury Water Department
Operator location Danbury, Connecticut - larger served population (> 3,309) at 62,055 people served; 326 SDWIS violations on record from surface water sources.
- 62,055
- People served (this PWS)
- 326
- EPA violations (this PWS)
- 4
- Health-based (this PWS)
- 4 PFAS
- UCMR5 (this PWS)
Danbury Water Department standing, high SDWIS violation third
62,055 people served (SDWIS) - larger served population (> 3,309). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 1% is middle-third health share (≤ 23%). UCMR5: middle-third PFAS panel (≤ 4 compounds). Population rank #859 of 29,740 among systems serving 500+.
The verdict
Danbury Water Department sits in the upper third of the sitemap cohort by violation count (326), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is large (62,055; larger served population (> 3,309)), so household exposure scale sits behind the violation mix. Health-based share is 1% (middle-third health share (≤ 23%)). UCMR5 detected 4 PFAS compounds (middle-third PFAS panel (≤ 4 compounds)).
- #859 of 29,740
- Population · /systems
- #8 of 184
- Population · CT
- 326
- Total EPA violations on record
- 1%
- Health-based (MCL / treatment failure)
Population ordinals match the sitemap cohort (systems serving 500+, population_served DESC). See methodology · corpus placement.
4 PFAS "forever chemicals" detected in testing under EPA's UCMR5 monitoring program.
System Details
- System Type
- Community
- Owner Type
- Local
- Connections
- 11,000
- County
- Fairfield
- School/Daycare
- No
- MCL Violations
- 0
- Monitoring Violations
- 293
- Treatment Tech Violations
- 4
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Nitrate | MR | 8 | 2012 |
| Nitrite | MR | 8 | 2012 |
| Total Haloacetic Acids (HAA5) | MR | 8 | 2021 |
| CARBON, TOTAL | MR | 6 | 2017 |
| BHC-GAMMA | MR | 5 | 1996 |
| Toxaphene | MR | 5 | 1996 |
| 2,4,5-TP | MR | 5 | 1996 |
| Aldicarb | MR | 5 | 1996 |
| Aldicarb sulfone | MR | 5 | 1996 |
| LASSO | MR | 5 | 1996 |
| TTHM | MR | 5 | 2017 |
| Lead and Copper Rule | MR | 5 | 2020 |
| Atrazine | MR | 5 | 1996 |
| Benzo(a)pyrene | MR | 5 | 1996 |
| Dalapon | MR | 5 | 1996 |
| Di(2-ethylhexyl) phthalate | MR | 5 | 1996 |
| Endothall | MR | 5 | 1996 |
| Glyphosate | MR | 5 | 1996 |
| HEXACHLOROBENZENE | MR | 5 | 1996 |
| Carbofuran | MR | 5 | 1996 |
| Simazine | MR | 5 | 1996 |
| 2,3,7,8-TCDD | MR | 5 | 1996 |
| 2,4-D | MR | 5 | 1996 |
| ETHYLENE DIBROMIDE | MR | 5 | 1996 |
| Heptachlor | MR | 5 | 1996 |
| Heptachlor epoxide | MR | 5 | 1996 |
| Dinoseb | MR | 5 | 1996 |
| Picloram | MR | 5 | 1996 |
| Chlordane | MR | 5 | 1996 |
| Di(2-ethylhexyl) adipate | MR | 5 | 1996 |
Violation Count vs. the National Corpus
Danbury Water Department has 326 recorded EPA violations, 92% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 8% carry more. 1% of this system's own violations are health-based (4 of 326), and it ranks #859 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)
326 Higher than most more violations than 92% 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. 16 of 232 samples detected PFAS.
| Contaminant | Date | Result | MRL | Status |
|---|---|---|---|---|
| PFTA | 9/17/2025 | <8.00 ppt | 8.00 ppt | Not Detected |
| PFHxS | 9/17/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHpS | 9/17/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| NEtFOSAA | 9/17/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFTrDA | 9/17/2025 | <7.00 ppt | 7.00 ppt | Not Detected |
| NMeFOSAA | 9/17/2025 | <6.00 ppt | 6.00 ppt | Not Detected |
| PFHpA | 9/17/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFNA | 9/17/2025 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFOS | 9/17/2025 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFOA | 9/17/2025 | 5.00 ppt | 4.00 ppt | Detected |
| PFDA | 9/17/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFDoA | 9/17/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHxA | 9/17/2025 | 3.60 ppt | 3.00 ppt | Detected |
| PFUnA | 9/17/2025 | <2.00 ppt | 2.00 ppt | Not Detected |
| 11Cl-PF3OUdS | 9/17/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFMBA | 9/17/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFPeS | 9/17/2025 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFBS | 9/17/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| 9Cl-PF3ONS | 9/17/2025 | <2.00 ppt | 2.00 ppt | Not Detected |
| NFDHA | 9/17/2025 | <20.00 ppt | 20.00 ppt | Not Detected |
| PFEESA | 9/17/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFPeA | 9/17/2025 | 3.40 ppt | 3.00 ppt | Detected |
| PFMPA | 9/17/2025 | <4.00 ppt | 4.00 ppt | Not Detected |
| 8:2 FTS | 9/17/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| 4:2 FTS | 9/17/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| 6:2 FTS | 9/17/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFBA | 9/17/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| HFPO-DA | 9/17/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| ADONA | 9/17/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFTA | 9/17/2025 | <8.00 ppt | 8.00 ppt | Not Detected |
| 6:2 FTS | 9/17/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| 4:2 FTS | 9/17/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| 8:2 FTS | 9/17/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFMPA | 9/17/2025 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFMBA | 9/17/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFEESA | 9/17/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFBA | 9/17/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFTrDA | 9/17/2025 | <7.00 ppt | 7.00 ppt | Not Detected |
| NEtFOSAA | 9/17/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| NMeFOSAA | 9/17/2025 | <6.00 ppt | 6.00 ppt | Not Detected |
| NFDHA | 9/17/2025 | <20.00 ppt | 20.00 ppt | Not Detected |
| PFOA | 9/17/2025 | 4.40 ppt | 4.00 ppt | Detected |
| PFHpS | 9/17/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| HFPO-DA | 9/17/2025 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFHxS | 9/17/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHpA | 9/17/2025 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFOS | 9/17/2025 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFBS | 9/17/2025 | 4.30 ppt | 3.00 ppt | Detected |
| PFUnA | 9/17/2025 | <2.00 ppt | 2.00 ppt | Not Detected |
| 9Cl-PF3ONS | 9/17/2025 | <2.00 ppt | 2.00 ppt | Not Detected |
Population served record for Danbury Water Department
EPA SDWIS lists 62,055 people served and 11,000 connections for this PWS, confirm the service-area footprint on the federal report before comparing to municipal census totals.
Sources: EPA SDWIS
Nationwide peers
326 violations · 62,055 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 Danbury Water Department
Use this system's EPA-reported record as a starting filter, not a final verdict.
- See how every tracked system in Connecticut compares on the same EPA violation measures. Connecticut 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.