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DEKALB

PWS ID: IL0370100 · DEKALB, Illinois 60115

DEKALB serves 45,000 people in DEKALB, Illinois using Groundwater water sources. It has 105 recorded EPA violations, including 66 health-based violations. PFAS "forever chemicals" were detected in UCMR5 testing (1 compound found).

Water Quality Snapshot: DEKALB

DEKALB is a local-owned community water system that delivers drinking water to 45,000 residents in DEKALB, Illinois (DeKalb County) through 11,104 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 105 total violations for this system , of which 66 (63%) are health-based — meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 17 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 Combined Radium (-226 and -228), recorded in 60 violations (MCL, health-based). Under EPA's UCMR5 PFAS monitoring program, 1 PFAS compound was detected in samples collected from this system, with a maximum reported concentration of 18.9 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. DEKALB's 105 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.

PFAS Detected

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

Population Served
45,000
Total Violations
105
Health-Based Violations
66
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Local
Connections
11,104
County
DeKalb
School/Daycare
No
MCL Violations
66
Monitoring Violations
17
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Combined Radium (-226 and -228) MCL 60 1998
Coliform (TCR) MCL 6 1992
Combined Radium (-226 and -228) MR 5 2022
Revised Total Coliform Rule MON 4 2018
Chlorine MR 4 2018
Coliform (TCR) MR 2 1999
Lead and Copper Rule MR 1 1992
Gross Alpha, Excl. Radon and U MR 1 1977
Consumer Confidence Rule Other 1 2025

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 3 of 300 samples detected PFAS.

Contaminant Date Result MRL Status
PFTrDA 4/18/2023 <0.007 µg/L 0.007 µg/L Not Detected
HFPO-DA 4/18/2023 <0.005 µg/L 0.005 µg/L Not Detected
PFMBA 4/18/2023 <0.003 µg/L 0.003 µg/L Not Detected
4:2 FTS 4/18/2023 <0.003 µg/L 0.003 µg/L Not Detected
8:2 FTS 4/18/2023 <0.005 µg/L 0.005 µg/L Not Detected
PFMPA 4/18/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFPeA 4/18/2023 <0.003 µg/L 0.003 µg/L Not Detected
6:2 FTS 4/18/2023 <0.005 µg/L 0.005 µg/L Not Detected
PFEESA 4/18/2023 <0.003 µg/L 0.003 µg/L Not Detected
NFDHA 4/18/2023 <0.02 µg/L 0.02 µg/L Not Detected
PFPeS 4/18/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFTA 4/18/2023 <0.008 µg/L 0.008 µg/L Not Detected
9Cl-PF3ONS 4/18/2023 <0.002 µg/L 0.002 µg/L Not Detected
NEtFOSAA 4/18/2023 <0.005 µg/L 0.005 µg/L Not Detected
NMeFOSAA 4/18/2023 <0.006 µg/L 0.006 µg/L Not Detected
ADONA 4/18/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFHpS 4/18/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFOS 4/18/2023 <0.004 µg/L 0.004 µg/L Not Detected
11Cl-PF3OUdS 4/18/2023 <0.005 µg/L 0.005 µg/L Not Detected
PFBA 4/18/2023 <0.005 µg/L 0.005 µg/L Not Detected
PFHpA 4/18/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFNA 4/18/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFBS 4/18/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFOA 4/18/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFDA 4/18/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFDoA 4/18/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFHxA 4/18/2023 <0.003 µg/L 0.003 µg/L Not Detected
lithium 4/18/2023 <9 µg/L 9 µg/L Not Detected
PFUnA 4/18/2023 <0.002 µg/L 0.002 µg/L Not Detected
PFHxS 4/18/2023 <0.003 µg/L 0.003 µg/L Not Detected
8:2 FTS 4/18/2023 <0.005 µg/L 0.005 µg/L Not Detected
9Cl-PF3ONS 4/18/2023 <0.002 µg/L 0.002 µg/L Not Detected
ADONA 4/18/2023 <0.003 µg/L 0.003 µg/L Not Detected
HFPO-DA 4/18/2023 <0.005 µg/L 0.005 µg/L Not Detected
PFBA 4/18/2023 <0.005 µg/L 0.005 µg/L Not Detected
6:2 FTS 4/18/2023 <0.005 µg/L 0.005 µg/L Not Detected
4:2 FTS 4/18/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFMPA 4/18/2023 <0.004 µg/L 0.004 µg/L Not Detected
lithium 4/18/2023 <9 µg/L 9 µg/L Not Detected
PFMBA 4/18/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFHpS 4/18/2023 <0.003 µg/L 0.003 µg/L Not Detected
NFDHA 4/18/2023 <0.02 µg/L 0.02 µg/L Not Detected
PFPeS 4/18/2023 <0.004 µg/L 0.004 µg/L Not Detected
11Cl-PF3OUdS 4/18/2023 <0.005 µg/L 0.005 µg/L Not Detected
PFPeA 4/18/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFTA 4/18/2023 <0.008 µg/L 0.008 µg/L Not Detected
PFEESA 4/18/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFTrDA 4/18/2023 <0.007 µg/L 0.007 µg/L Not Detected
NEtFOSAA 4/18/2023 <0.005 µg/L 0.005 µg/L Not Detected
NMeFOSAA 4/18/2023 <0.006 µg/L 0.006 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 DEKALB.

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 IL0370100 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 DEKALB 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 1 SDWIS / IL0370100 / 7000
2022 Combined Radium (-226 and -228) MR 5 SDWIS / IL0370100 / 4010
2018 Revised Total Coliform Rule MON 4 SDWIS / IL0370100 / 8000
2018 Chlorine MR 4 SDWIS / IL0370100 / 0999
1999 Coliform (TCR) MR 2 SDWIS / IL0370100 / 3100
1998 Combined Radium (-226 and -228) MCL 60 SDWIS / IL0370100 / 4010
1992 Coliform (TCR) MCL 6 SDWIS / IL0370100 / 3100
1992 Lead and Copper Rule MR 1 SDWIS / IL0370100 / 5000
1977 Gross Alpha, Excl. Radon and U MR 1 SDWIS / IL0370100 / 4000

How DEKALB Compares

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

Metric DEKALB Illinois avg Federal benchmark
Total violations 105 69.4 SDWA compliance — any non-zero count is a recorded breach
Health-based violations 66 10.3 Indicates a contaminant exceeded a federal MCL
PFAS detection 1 compound 40.9% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 45,000 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 DEKALB water safe to drink? ▼
DEKALB (PWS ID: IL0370100) has 105 recorded violations in the EPA SDWIS database. PFAS contamination has been detected in UCMR5 testing, with 1 PFAS compound found. This system serves 45,000 people using Groundwater sources.
How many people does DEKALB serve? ▼
DEKALB serves 45,000 people in DEKALB, Illinois. It is a Local-owned system using Groundwater water sources with 11,104 service connections.
What type of violations does DEKALB have? ▼
DEKALB has 105 total violations: 66 health-based violations (MCL exceedances or treatment failures), 17 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in DEKALB water? ▼
Yes. UCMR5 testing detected 1 PFAS compound in DEKALB's water supply: lithium. PFAS are persistent "forever chemicals" that do not break down in the environment.
What water source does DEKALB use? ▼
DEKALB 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