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ALGONQUIN

PWS ID: IL1110050 · ALGONQUIN, Illinois 60102

ALGONQUIN serves 30,700 people in ALGONQUIN, Illinois using Groundwater water sources. It has 83 recorded EPA violations, including 29 health-based violations. No PFAS contamination was detected in UCMR5 testing.

Water Quality Snapshot: ALGONQUIN

ALGONQUIN is a local-owned community water system that delivers drinking water to 30,700 residents in ALGONQUIN, Illinois (McHenry County) through 11,904 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 83 total violations for this system , of which 29 (35%) are health-based — meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 25 monitoring and reporting violations are on file. The most recent violation on record dates to 2007.

The most frequently cited contaminant at this system is Barium, recorded in 19 violations (MCL, health-based). This system was sampled under EPA's UCMR5 PFAS monitoring program and no PFAS compounds were detected above the minimum reporting level.

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. ALGONQUIN's 83 violations sit above 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.

Population Served
30,700
Total Violations
83
Health-Based Violations
29
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Local
Connections
11,904
County
McHenry
School/Daycare
No
MCL Violations
23
Monitoring Violations
25
Treatment Tech Violations
6

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Barium MCL 19 1986
Coliform (TCR) MR 12 2006
Lead and Copper Rule MR 8 1999
Lead and Copper Rule TT 6 1993
Chlorine MR 4 2006
Coliform (TCR) MCL 4 2006
Public Notice Other 2 2007
Gross Alpha, Excl. Radon and U MR 1 1977

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 0 of 240 samples detected PFAS.

Contaminant Date Result MRL Status
PFTrDA 5/15/2024 <0.007 µg/L 0.007 µg/L Not Detected
NEtFOSAA 5/15/2024 <0.005 µg/L 0.005 µg/L Not Detected
PFHpS 5/15/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFTA 5/15/2024 <0.008 µg/L 0.008 µg/L Not Detected
9Cl-PF3ONS 5/15/2024 <0.002 µg/L 0.002 µg/L Not Detected
NMeFOSAA 5/15/2024 <0.006 µg/L 0.006 µg/L Not Detected
lithium 5/15/2024 <9 µg/L 9 µg/L Not Detected
PFBS 5/15/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFHxS 5/15/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFNA 5/15/2024 <0.004 µg/L 0.004 µg/L Not Detected
PFOS 5/15/2024 <0.004 µg/L 0.004 µg/L Not Detected
PFOA 5/15/2024 <0.004 µg/L 0.004 µg/L Not Detected
PFDA 5/15/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFDoA 5/15/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFHxA 5/15/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFHpA 5/15/2024 <0.003 µg/L 0.003 µg/L Not Detected
11Cl-PF3OUdS 5/15/2024 <0.005 µg/L 0.005 µg/L Not Detected
PFPeS 5/15/2024 <0.004 µg/L 0.004 µg/L Not Detected
ADONA 5/15/2024 <0.003 µg/L 0.003 µg/L Not Detected
HFPO-DA 5/15/2024 <0.005 µg/L 0.005 µg/L Not Detected
PFBA 5/15/2024 <0.005 µg/L 0.005 µg/L Not Detected
6:2 FTS 5/15/2024 <0.005 µg/L 0.005 µg/L Not Detected
4:2 FTS 5/15/2024 <0.003 µg/L 0.003 µg/L Not Detected
8:2 FTS 5/15/2024 <0.005 µg/L 0.005 µg/L Not Detected
PFMPA 5/15/2024 <0.004 µg/L 0.004 µg/L Not Detected
PFPeA 5/15/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFMBA 5/15/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFEESA 5/15/2024 <0.003 µg/L 0.003 µg/L Not Detected
NFDHA 5/15/2024 <0.02 µg/L 0.02 µg/L Not Detected
PFUnA 5/15/2024 <0.002 µg/L 0.002 µg/L Not Detected
PFBA 5/15/2024 <0.005 µg/L 0.005 µg/L Not Detected
NMeFOSAA 5/15/2024 <0.006 µg/L 0.006 µg/L Not Detected
PFDA 5/15/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFDoA 5/15/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFHxA 5/15/2024 <0.003 µg/L 0.003 µg/L Not Detected
11Cl-PF3OUdS 5/15/2024 <0.005 µg/L 0.005 µg/L Not Detected
9Cl-PF3ONS 5/15/2024 <0.002 µg/L 0.002 µg/L Not Detected
8:2 FTS 5/15/2024 <0.005 µg/L 0.005 µg/L Not Detected
HFPO-DA 5/15/2024 <0.005 µg/L 0.005 µg/L Not Detected
PFOS 5/15/2024 <0.004 µg/L 0.004 µg/L Not Detected
6:2 FTS 5/15/2024 <0.005 µg/L 0.005 µg/L Not Detected
4:2 FTS 5/15/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFEESA 5/15/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFHxS 5/15/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFHpA 5/15/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFBS 5/15/2024 <0.003 µg/L 0.003 µg/L Not Detected
ADONA 5/15/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFTrDA 5/15/2024 <0.007 µg/L 0.007 µg/L Not Detected
PFHpS 5/15/2024 <0.003 µg/L 0.003 µg/L Not Detected
PFMPA 5/15/2024 <0.004 µg/L 0.004 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 ALGONQUIN.

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 IL1110050 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 ALGONQUIN 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
2007 Public Notice Other 2 SDWIS / IL1110050 / 7500
2006 Coliform (TCR) MR 12 SDWIS / IL1110050 / 3100
2006 Chlorine MR 4 SDWIS / IL1110050 / 0999
2006 Coliform (TCR) MCL 4 SDWIS / IL1110050 / 3100
1999 Lead and Copper Rule MR 8 SDWIS / IL1110050 / 5000
1993 Lead and Copper Rule TT 6 SDWIS / IL1110050 / 5000
1986 Barium MCL 19 SDWIS / IL1110050 / 1010
1977 Gross Alpha, Excl. Radon and U MR 1 SDWIS / IL1110050 / 4000

How ALGONQUIN Compares

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

Metric ALGONQUIN Illinois avg Federal benchmark
Total violations 83 69.4 SDWA compliance — any non-zero count is a recorded breach
Health-based violations 29 10.3 Indicates a contaminant exceeded a federal MCL
PFAS detection None 40.9% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 30,700 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 ALGONQUIN water safe to drink? ▼
ALGONQUIN (PWS ID: IL1110050) has 83 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 30,700 people using Groundwater sources.
How many people does ALGONQUIN serve? ▼
ALGONQUIN serves 30,700 people in ALGONQUIN, Illinois. It is a Local-owned system using Groundwater water sources with 11,904 service connections.
What type of violations does ALGONQUIN have? ▼
ALGONQUIN has 83 total violations: 29 health-based violations (MCL exceedances or treatment failures), 25 monitoring/reporting violations, and 6 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in ALGONQUIN water? ▼
No. ALGONQUIN was tested for PFAS under the EPA's UCMR5 monitoring program and no PFAS contamination was detected.
What water source does ALGONQUIN use? ▼
ALGONQUIN 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