Community Water System · PWS CT0798013
Aquarion-Marlborough
Operator location Shelton, Connecticut - upper-third violation load (> 74 violations) with 633 EPA violations; groundwater source; 1,348 served (PWS-level, not municipal population).
- 1,348
- People served (this PWS)
- 633
- EPA violations (this PWS)
- 8
- Health-based (this PWS)
- Untested
- UCMR5 (this PWS)
Aquarion-Marlborough standing, high SDWIS violation third
633 EPA SDWIS violations on record - upper-third violation load (> 74 violations). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 1% is middle-third health share (≤ 23%). Population rank #16,876 of 29,740 among systems serving 500+.
The verdict
Aquarion-Marlborough sits in the upper third of the sitemap cohort by violation count (633), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is mid-pack at 1,348 (mid served population (≤ 3,309)). Health-based share is 1% (middle-third health share (≤ 23%)). No UCMR5 PFAS test appears for this system in this extract.
- #16,876 of 29,740
- Population · /systems
- #89 of 184
- Population · CT
- 633
- 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.
System Details
- System Type
- Community
- Owner Type
- Local
- Connections
- 128
- County
- Hartford
- School/Daycare
- Yes
- MCL Violations
- 8
- Monitoring Violations
- 623
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| DICHLOROMETHANE | MR | 12 | 2019 |
| p-Dichlorobenzene | MR | 12 | 2019 |
| Vinyl chloride | MR | 12 | 2019 |
| trans-1,2-Dichloroethylene | MR | 12 | 2019 |
| 1,2-Dichloroethane | MR | 12 | 2019 |
| Carbon tetrachloride | MR | 12 | 2019 |
| Trichloroethylene | MR | 12 | 2019 |
| Benzene | MR | 12 | 2019 |
| Ethylbenzene | MR | 12 | 2019 |
| Styrene | MR | 12 | 2019 |
| Endrin | MR | 12 | 2019 |
| Toxaphene | MR | 12 | 2019 |
| Diquat | MR | 12 | 2019 |
| 1,2,4-Trichlorobenzene | MR | 12 | 2019 |
| Simazine | MR | 12 | 2019 |
| Picloram | MR | 12 | 2019 |
| Hexachlorocyclopentadiene | MR | 12 | 2019 |
| Aldicarb sulfoxide | MR | 12 | 2019 |
| Aldicarb sulfone | MR | 12 | 2019 |
| Carbofuran | MR | 12 | 2019 |
| cis-1,2-Dichloroethylene | MR | 12 | 2019 |
| Heptachlor | MR | 12 | 2019 |
| 2,4-D | MR | 12 | 2019 |
| Benzo(a)pyrene | MR | 12 | 2019 |
| Pentachlorophenol | MR | 12 | 2019 |
| ETHYLENE DIBROMIDE | MR | 12 | 2019 |
| BHC-GAMMA | MR | 12 | 2019 |
| Dalapon | MR | 12 | 2019 |
| Glyphosate | MR | 12 | 2019 |
| Di(2-ethylhexyl) phthalate | MR | 12 | 2019 |
Violation Count vs. the National Corpus
Aquarion-Marlborough has 633 recorded EPA violations, 97% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 3% carry more. 1% of this system's own violations are health-based (8 of 633), and it ranks #16,876 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)
633 Higher than most more violations than 97% 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
SDWIS compliance record for Aquarion-Marlborough
633 violations on record for CT0798013; use EPA SDWIS to confirm return-to-compliance dates and monitoring categories.
Sources: EPA SDWIS
Nationwide peers
633 violations · 1,348 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 near this population served
Nearest cross-state systems by EPA SDWIS population_served (same 500+ sitemap gate).
What to do with Aquarion-Marlborough
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.