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Community Water System · PWS CT1100011

Aquarion-Plainville Regional

Shelton, Connecticut 06484 - drinking water served from groundwater sources to 18,231 people, tracked in EPA SDWIS and UCMR5.

18,231
People served
63
EPA violations
0
Health-based
3 PFAS
UCMR5 result

The verdict

EPA records 63 drinking-water violations at Aquarion-Plainville Regional - below the Connecticut per-system average, and UCMR5 testing detected 3 PFAS compounds.

63
Total EPA violations on record
0%
Health-based (MCL / treatment failure)
18,231
People served by this system
3
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Aquarion-Plainville Regional

Aquarion-Plainville Regional is a private-owned community water system that delivers drinking water to 18,231 residents in Shelton, Connecticut (Hartford County) through 6,622 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 63 total violations for this system , of which 0 (0%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 47 monitoring and reporting violations are on file. The most recent violation on record dates to 2021.

The most frequently cited contaminant at this system is Consumer Confidence Rule, recorded in 11 violations (Other). Under EPA's UCMR5 PFAS monitoring program, 3 PFAS compounds were detected in samples collected from this system, with a maximum reported concentration of 6.8 ppt (parts per trillion). PFAS are persistent synthetic chemicals linked to health effects at very low exposure levels.

Across Connecticut, EPA tracks 2,332 public water systems serving 2,886,005 people, with 206,662 cumulative violations and 21,779 health-based violations on record. About 94% of systems in the state carry at least one violation, and state-wide the average per system is 88.6 violations. Statewide, 40 of 63 UCMR5-tested systems have reported PFAS detections (63.5%).

Aquarion-Plainville Regional's 63 violations sit below the Connecticut average.

All figures above are sourced directly from EPA SDWIS and UCMR5 public data releases and are updated as EPA publishes new reporting cycles.

PFAS Detected

3 PFAS "forever chemicals" detected in testing under EPA's UCMR5 monitoring program.

Population Served
18,231
Total Violations
63
Health-Based Violations
0
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Private
Connections
6,622
County
Hartford
School/Daycare
No
MCL Violations
0
Monitoring Violations
47
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Consumer Confidence Rule Other 11 2021
Total Haloacetic Acids (HAA5) MR 7 2016
TTHM MR 7 2016
Coliform (TCR) MR 5 2013
ManMade Beta Particle and Photon Emitter MR 4 2006
Gross Beta Particle Activity MR 4 2006
Gross Alpha, Excl. Radon and U MR 4 2011
Combined Radium (-226 and -228) MR 4 2011
Combined Uranium MR 4 2011
Chlorine MR 2 2005
p-Dichlorobenzene MR 1 1988
Cadmium MR 1 2019
Arsenic MR 1 2019
Antimony, Total MR 1 2019
Benzene MR 1 1988
Beryllium, Total MR 1 2019

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 6 of 116 samples detected PFAS.

Contaminant Date Result MRL Status
4:2 FTS 8/8/2023 <3.00 ppt 3.00 ppt Not Detected
6:2 FTS 8/8/2023 <5.00 ppt 5.00 ppt Not Detected
8:2 FTS 8/8/2023 <5.00 ppt 5.00 ppt Not Detected
HFPO-DA 8/8/2023 <5.00 ppt 5.00 ppt Not Detected
ADONA 8/8/2023 <3.00 ppt 3.00 ppt Not Detected
11Cl-PF3OUdS 8/8/2023 <5.00 ppt 5.00 ppt Not Detected
9Cl-PF3ONS 8/8/2023 <2.00 ppt 2.00 ppt Not Detected
PFDoA 8/8/2023 <3.00 ppt 3.00 ppt Not Detected
PFOA 8/8/2023 4.70 ppt 4.00 ppt Detected
PFBA 8/8/2023 6.40 ppt 5.00 ppt Detected
PFDA 8/8/2023 <3.00 ppt 3.00 ppt Not Detected
NMeFOSAA 8/8/2023 <6.00 ppt 6.00 ppt Not Detected
NEtFOSAA 8/8/2023 <5.00 ppt 5.00 ppt Not Detected
PFOS 8/8/2023 6.20 ppt 4.00 ppt Detected
PFTA 8/8/2023 <8.00 ppt 8.00 ppt Not Detected
PFBS 8/8/2023 <3.00 ppt 3.00 ppt Not Detected
PFTrDA 8/8/2023 <7.00 ppt 7.00 ppt Not Detected
PFEESA 8/8/2023 <3.00 ppt 3.00 ppt Not Detected
PFMPA 8/8/2023 <4.00 ppt 4.00 ppt Not Detected
PFUnA 8/8/2023 <2.00 ppt 2.00 ppt Not Detected
PFMBA 8/8/2023 <3.00 ppt 3.00 ppt Not Detected
PFHpS 8/8/2023 <3.00 ppt 3.00 ppt Not Detected
PFPeA 8/8/2023 <3.00 ppt 3.00 ppt Not Detected
NFDHA 8/8/2023 <20.00 ppt 20.00 ppt Not Detected
PFHpA 8/8/2023 <3.00 ppt 3.00 ppt Not Detected
PFHxS 8/8/2023 <3.00 ppt 3.00 ppt Not Detected
PFNA 8/8/2023 <4.00 ppt 4.00 ppt Not Detected
PFHxA 8/8/2023 <3.00 ppt 3.00 ppt Not Detected
PFPeS 8/8/2023 <4.00 ppt 4.00 ppt Not Detected
PFTA 8/8/2023 <8.00 ppt 8.00 ppt Not Detected
PFNA 8/8/2023 <4.00 ppt 4.00 ppt Not Detected
NMeFOSAA 8/8/2023 <6.00 ppt 6.00 ppt Not Detected
PFTrDA 8/8/2023 <7.00 ppt 7.00 ppt Not Detected
NEtFOSAA 8/8/2023 <5.00 ppt 5.00 ppt Not Detected
PFBA 8/8/2023 <5.00 ppt 5.00 ppt Not Detected
PFBS 8/8/2023 <3.00 ppt 3.00 ppt Not Detected
PFHpA 8/8/2023 <3.00 ppt 3.00 ppt Not Detected
PFOA 8/8/2023 <4.00 ppt 4.00 ppt Not Detected
PFDA 8/8/2023 <3.00 ppt 3.00 ppt Not Detected
4:2 FTS 8/8/2023 <3.00 ppt 3.00 ppt Not Detected
6:2 FTS 8/8/2023 <5.00 ppt 5.00 ppt Not Detected
8:2 FTS 8/8/2023 <5.00 ppt 5.00 ppt Not Detected
PFMPA 8/8/2023 <4.00 ppt 4.00 ppt Not Detected
PFMBA 8/8/2023 <3.00 ppt 3.00 ppt Not Detected
PFEESA 8/8/2023 <3.00 ppt 3.00 ppt Not Detected
PFOS 8/8/2023 <4.00 ppt 4.00 ppt Not Detected
HFPO-DA 8/8/2023 <5.00 ppt 5.00 ppt Not Detected
PFHxS 8/8/2023 <3.00 ppt 3.00 ppt Not Detected
11Cl-PF3OUdS 8/8/2023 <5.00 ppt 5.00 ppt Not Detected
NFDHA 8/8/2023 <20.00 ppt 20.00 ppt Not Detected

Verify This Water System

The figures above are aggregated from EPA's public databases. To verify the underlying records, or to file a complaint, request a Consumer Confidence Report, or check current monitoring status, go directly to the federal and state regulators that enforce the Safe Drinking Water Act for Aquarion-Plainville Regional.

Federal Source of Truth

EPA SDWIS, Federal Reports

EPA's Safe Drinking Water Information System (SDWIS) holds the federal compliance record for every regulated public water system. Open the system-level report by PWS ID:

View PWS ID CT1100011 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

Connecticut Drinking Water Authority

Connecticut's primacy agency administers the Safe Drinking Water Act locally. Search EPA SDWIS for the current state contact, or use the state's public health or environment department portal.

Find CT regulator via EPA SDWIS

Violation Timeline

Each row links to the EPA SDWIS public record for verification. Cross-reference the contaminant code on EPA's federal report to see violation dates, return-to-compliance status, and enforcement actions.

Year (latest) Contaminant Category Count EPA Record
2021 Consumer Confidence Rule Other 11 SDWIS / CT1100011 / 7000
2019 Cadmium MR 1 SDWIS / CT1100011 / 1015
2019 Arsenic MR 1 SDWIS / CT1100011 / 1005
2019 Antimony, Total MR 1 SDWIS / CT1100011 / 1074
2019 Beryllium, Total MR 1 SDWIS / CT1100011 / 1075
2016 Total Haloacetic Acids (HAA5) MR 7 SDWIS / CT1100011 / 2456
2016 TTHM MR 7 SDWIS / CT1100011 / 2950
2013 Coliform (TCR) MR 5 SDWIS / CT1100011 / 3100
2011 Gross Alpha, Excl. Radon and U MR 4 SDWIS / CT1100011 / 4000
2011 Combined Radium (-226 and -228) MR 4 SDWIS / CT1100011 / 4010
2011 Combined Uranium MR 4 SDWIS / CT1100011 / 4006
2006 ManMade Beta Particle and Photon Emitter MR 4 SDWIS / CT1100011 / 4101
2006 Gross Beta Particle Activity MR 4 SDWIS / CT1100011 / 4100
2005 Chlorine MR 2 SDWIS / CT1100011 / 0999
1988 p-Dichlorobenzene MR 1 SDWIS / CT1100011 / 2969

How Aquarion-Plainville Regional Compares

Cross-reference this system's record against state averages and the federal MCL framework for context.

Metric Aquarion-Plainville Regional Connecticut avg Federal benchmark
Total violations 63 88.6 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 0 9.3 Indicates a contaminant exceeded a federal MCL
PFAS detection 3 compounds 63.5% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 18,231 1,238 Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 2,332 regulated public water systems in Connecticut.

Federal MCL reference, Safe Drinking Water Act thresholds ▼
Contaminant Federal MCL / Action Level Note
Lead 0 mg/L (Action Level: 0.015 mg/L) Lead and Copper Rule treatment technique
Arsenic 0.010 mg/L (10 ppb) Health-based MCL since 2006
Total Coliform Treatment technique (RTCR) Indicator organism, monitoring trigger
PFOA / PFOS (PFAS) 4.0 ppt each (final 2024 rule) Compliance deadline 2029 (EPA proposed extending to 2031, not yet final as of May 2026)
Nitrate (as N) 10 mg/L Acute health risk for infants

Frequently Asked Questions

Is Aquarion-Plainville Regional water safe to drink? ▼
Aquarion-Plainville Regional (PWS ID: CT1100011) has 63 recorded violations in the EPA SDWIS database. PFAS contamination has been detected in UCMR5 testing, with 3 PFAS compounds found. This system serves 18,231 people using Groundwater sources.
How many people does Aquarion-Plainville Regional serve? ▼
Aquarion-Plainville Regional serves 18,231 people in Shelton, Connecticut. It is a Private-owned system using Groundwater water sources with 6,622 service connections.
What type of violations does Aquarion-Plainville Regional have? ▼
Aquarion-Plainville Regional has 63 total violations: 0 health-based violations (MCL exceedances or treatment failures), 47 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Aquarion-Plainville Regional water? ▼
Yes. UCMR5 testing detected 3 PFAS compounds in Aquarion-Plainville Regional's water supply: PFOA, PFBA, PFOS. PFAS are persistent "forever chemicals" that do not break down in the environment.
What water source does Aquarion-Plainville Regional use? ▼
Aquarion-Plainville Regional uses Groundwater as its primary water source. It is classified as a Community Water System (CWS), serving residential populations year-round.
Where does this data come from? ▼
All data comes from the EPA Safe Drinking Water Information System (SDWIS) and the UCMR5 PFAS monitoring program. SDWIS tracks compliance for all public water systems regulated under the Safe Drinking Water Act.
Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025. PFAS data from EPA UCMR5 monitoring program (2023-2025). This data is provided for informational purposes only.

Read our methodology - how this data is sourced, computed, and verified.

Data sourced from EPA SDWIS and UCMR5 PFAS monitoring data. See our methodology for details. Retrieved and formatted by PlainWater Editorial

Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. This system's figures are rendered directly from EPA SDWIS data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.