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CARY

PWS ID: IL1110100 · CARY, Illinois 60013

CARY serves 17,826 people in CARY, Illinois using Groundwater water sources. It has 66 recorded EPA violations, including 48 health-based violations. PFAS "forever chemicals" were detected in UCMR5 testing (5 compounds found).

Water Quality Snapshot: CARY

CARY is a local-owned community water system that delivers drinking water to 17,826 residents in CARY, Illinois (McHenry County) through 6,469 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 66 total violations for this system , of which 48 (73%) are health-based — meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 9 monitoring and reporting violations are on file. The most recent violation on record dates to 2025.

The most frequently cited contaminant at this system is Barium, recorded in 20 violations (MCL, health-based). Under EPA's UCMR5 PFAS monitoring program, 5 PFAS compounds were detected in samples collected from this system, with a maximum reported concentration of 0.012 ppt. PFAS are persistent synthetic chemicals linked to health effects at very low exposure levels.

Across Illinois, EPA tracks 5,117 public water systems serving 12,576,876 people, with 355,322 cumulative violations and 52,932 health-based violations on record. About 81% of systems in the state carry at least one violation, and state-wide the average per system is 69.4 violations. CARY's 66 violations sit below the Illinois average. Statewide, 199 of 487 UCMR5-tested systems have reported PFAS detections (40.9%). 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

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

Population Served
17,826
Total Violations
66
Health-Based Violations
48
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Local
Connections
6,469
County
McHenry
School/Daycare
No
MCL Violations
46
Monitoring Violations
9
Treatment Tech Violations
2

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Barium MCL 20 1995
Gross Alpha, Excl. Radon and U MCL 13 1984
Combined Radium (-226 and -228) MCL 7 1984
Coliform (TCR) MR 6 1993
Coliform (TCR) MCL 6 1992
Consumer Confidence Rule Other 3 2025
Lead and Copper Rule MR 2 1993
Lead and Copper Rule TT 2 1992
Gross Alpha, Excl. Radon and U MR 1 1977

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 5 of 330 samples detected PFAS.

Contaminant Date Result MRL Status
PFHpS 7/16/2024 <0.003 µg/L 0.003 µg/L Not Detected
HFPO-DA 7/16/2024 <0.005 µg/L 0.005 µg/L Not Detected
ADONA 7/16/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFBA 7/16/2024 <0.005 µg/L 0.005 µg/L Not Detected
6:2 FTS 7/16/2024 <0.005 µg/L 0.005 µg/L Not Detected
4:2 FTS 7/16/2024 <0.003 µg/L 0.003 µg/L Not Detected
8:2 FTS 7/16/2024 <0.005 µg/L 0.005 µg/L Not Detected
PFMPA 7/16/2024 <0.004 µg/L 0.004 µg/L Not Detected
PFPeA 7/16/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFMBA 7/16/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFEESA 7/16/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFPeS 7/16/2024 <0.004 µg/L 0.004 µg/L Not Detected
PFNA 7/16/2024 <0.004 µg/L 0.004 µg/L Not Detected
9Cl-PF3ONS 7/16/2024 <0.002 µg/L 0.002 µg/L Not Detected
NFDHA 7/16/2024 <0.02 µg/L 0.02 µg/L Not Detected
NEtFOSAA 7/16/2024 <0.005 µg/L 0.005 µg/L Not Detected
PFOA 7/16/2024 <0.004 µg/L 0.004 µg/L Not Detected
NMeFOSAA 7/16/2024 <0.006 µg/L 0.006 µg/L Not Detected
PFTA 7/16/2024 <0.008 µg/L 0.008 µg/L Not Detected
11Cl-PF3OUdS 7/16/2024 <0.005 µg/L 0.005 µg/L Not Detected
PFTrDA 7/16/2024 <0.007 µg/L 0.007 µg/L Not Detected
lithium 7/16/2024 <9 µg/L 9 µg/L Not Detected
PFBS 7/16/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFHxA 7/16/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFHxS 7/16/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFUnA 7/16/2024 <0.002 µg/L 0.002 µg/L Not Detected
PFOS 7/16/2024 <0.004 µg/L 0.004 µg/L Not Detected
PFDA 7/16/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFDoA 7/16/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFHpA 7/16/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFTA 5/29/2024 <0.008 µg/L 0.008 µg/L Not Detected
PFMBA 5/29/2024 <0.003 µg/L 0.003 µg/L Not Detected
8:2 FTS 5/29/2024 <0.005 µg/L 0.005 µg/L Not Detected
PFMPA 5/29/2024 <0.004 µg/L 0.004 µg/L Not Detected
6:2 FTS 5/29/2024 <0.005 µg/L 0.005 µg/L Not Detected
PFPeA 5/29/2024 <0.003 µg/L 0.003 µg/L Not Detected
4:2 FTS 5/29/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFEESA 5/29/2024 <0.003 µg/L 0.003 µg/L Not Detected
NFDHA 5/29/2024 <0.02 µg/L 0.02 µg/L Not Detected
PFPeS 5/29/2024 <0.004 µg/L 0.004 µg/L Not Detected
lithium 5/29/2024 <9 µg/L 9 µg/L Not Detected
PFTrDA 5/29/2024 <0.007 µg/L 0.007 µg/L Not Detected
ADONA 5/29/2024 <0.003 µg/L 0.003 µg/L Not Detected
NEtFOSAA 5/29/2024 <0.005 µg/L 0.005 µg/L Not Detected
NMeFOSAA 5/29/2024 <0.006 µg/L 0.006 µg/L Not Detected
PFHpS 5/29/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFHxS 5/29/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFBA 5/29/2024 <0.005 µg/L 0.005 µg/L Not Detected
HFPO-DA 5/29/2024 <0.005 µg/L 0.005 µg/L Not Detected
PFHpA 5/29/2024 <0.003 µg/L 0.003 µg/L 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 CARY.

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 IL1110100 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

Illinois Drinking Water Authority

Illinois EPA — Bureau of Water is the primacy agency that licenses and inspects CARY under EPA-delegated authority.

Open IL regulator portal

Source: Illinois EPA — Bureau of Water

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
2025 Consumer Confidence Rule Other 3 SDWIS / IL1110100 / 7000
1995 Barium MCL 20 SDWIS / IL1110100 / 1010
1993 Coliform (TCR) MR 6 SDWIS / IL1110100 / 3100
1993 Lead and Copper Rule MR 2 SDWIS / IL1110100 / 5000
1992 Coliform (TCR) MCL 6 SDWIS / IL1110100 / 3100
1992 Lead and Copper Rule TT 2 SDWIS / IL1110100 / 5000
1984 Gross Alpha, Excl. Radon and U MCL 13 SDWIS / IL1110100 / 4000
1984 Combined Radium (-226 and -228) MCL 7 SDWIS / IL1110100 / 4010
1977 Gross Alpha, Excl. Radon and U MR 1 SDWIS / IL1110100 / 4000

How CARY Compares

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

Metric CARY Illinois avg Federal benchmark
Total violations 66 69.4 SDWA compliance — any non-zero count is a recorded breach
Health-based violations 48 10.3 Indicates a contaminant exceeded a federal MCL
PFAS detection 5 compounds 40.9% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 17,826 2,458 Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 5,117 regulated public water systems in Illinois.

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
Nitrate (as N) 10 mg/L Acute health risk for infants

Frequently Asked Questions

Is CARY water safe to drink? ▼
CARY (PWS ID: IL1110100) has 66 recorded violations in the EPA SDWIS database. PFAS contamination has been detected in UCMR5 testing, with 5 PFAS compounds found. This system serves 17,826 people using Groundwater sources.
How many people does CARY serve? ▼
CARY serves 17,826 people in CARY, Illinois. It is a Local-owned system using Groundwater water sources with 6,469 service connections.
What type of violations does CARY have? ▼
CARY has 66 total violations: 48 health-based violations (MCL exceedances or treatment failures), 9 monitoring/reporting violations, and 2 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in CARY water? ▼
Yes. UCMR5 testing detected 5 PFAS compounds in CARY's water supply: PFHxA, PFHpA, PFPeA, 6:2 FTS, PFBA. PFAS are persistent "forever chemicals" that do not break down in the environment.
What water source does CARY use? ▼
CARY 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.

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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.

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Data sourced from $official public datasets. See our methodology for details. Retrieved and formatted by PlainWater Editorial