PlainWater

Community Water System · PWS CT0798013

Aquarion-Marlborough

Shelton, Connecticut 06484 - drinking water served from groundwater sources to 1,348 people, tracked in EPA SDWIS and UCMR5.

1,348
People served
633
EPA violations
8
Health-based
Untested
UCMR5 result

The verdict

EPA records 633 drinking-water violations at Aquarion-Marlborough, 1% of them health-based - above the Connecticut per-system average.

633
Total EPA violations on record
1%
Health-based (MCL / treatment failure)
1,348
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Aquarion-Marlborough

Aquarion-Marlborough is a local-owned community water system that delivers drinking water to 1,348 residents in Shelton, Connecticut (Hartford County) through 128 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 633 total violations for this system , of which 8 (1%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 623 monitoring and reporting violations are on file. The most recent violation on record dates to 2019.

The most frequently cited contaminant at this system is DICHLOROMETHANE, recorded in 12 violations (MR). This system has not yet been sampled under EPA's UCMR5 PFAS monitoring program, so no PFAS detection data is available here.

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-Marlborough's 633 violations sit above 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.

Population Served
1,348
Total Violations
633
Health-Based Violations
8
Water Source
Groundwater

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

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-Marlborough.

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 CT0798013 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
2019 DICHLOROMETHANE MR 12 SDWIS / CT0798013 / 2964
2019 p-Dichlorobenzene MR 12 SDWIS / CT0798013 / 2969
2019 Vinyl chloride MR 12 SDWIS / CT0798013 / 2976
2019 trans-1,2-Dichloroethylene MR 12 SDWIS / CT0798013 / 2979
2019 1,2-Dichloroethane MR 12 SDWIS / CT0798013 / 2980
2019 Carbon tetrachloride MR 12 SDWIS / CT0798013 / 2982
2019 Trichloroethylene MR 12 SDWIS / CT0798013 / 2984
2019 Benzene MR 12 SDWIS / CT0798013 / 2990
2019 Ethylbenzene MR 12 SDWIS / CT0798013 / 2992
2019 Styrene MR 12 SDWIS / CT0798013 / 2996
2019 Endrin MR 12 SDWIS / CT0798013 / 2005
2019 Toxaphene MR 12 SDWIS / CT0798013 / 2020
2019 Diquat MR 12 SDWIS / CT0798013 / 2032
2019 1,2,4-Trichlorobenzene MR 12 SDWIS / CT0798013 / 2378
2019 Simazine MR 12 SDWIS / CT0798013 / 2037

How Aquarion-Marlborough Compares

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

Metric Aquarion-Marlborough Connecticut avg Federal benchmark
Total violations 633 88.6 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 8 9.3 Indicates a contaminant exceeded a federal MCL
PFAS detection None 63.5% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 1,348 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-Marlborough water safe to drink?
Aquarion-Marlborough (PWS ID: CT0798013) has 633 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 1,348 people using Groundwater sources.
How many people does Aquarion-Marlborough serve?
Aquarion-Marlborough serves 1,348 people in Shelton, Connecticut. It is a Local-owned system using Groundwater water sources with 128 service connections.
What type of violations does Aquarion-Marlborough have?
Aquarion-Marlborough has 633 total violations: 8 health-based violations (MCL exceedances or treatment failures), 623 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Aquarion-Marlborough water?
No PFAS testing data is available for Aquarion-Marlborough under the EPA's UCMR5 monitoring program.
What water source does Aquarion-Marlborough use?
Aquarion-Marlborough 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. This data is provided for informational purposes only.
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.