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Community Water System · PWS IL0430010

York Township Water System

Darien, Illinois 60561 - drinking water served from surface water sources to 1,423 people, tracked in EPA SDWIS and UCMR5.

1,423
People served
172
EPA violations
24
Health-based
Untested
UCMR5 result

The verdict

EPA records 172 drinking-water violations at York Township Water System, 14% of them health-based - above the Illinois per-system average.

172
Total EPA violations on record
14%
Health-based (MCL / treatment failure)
1,423
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: York Township Water System

York Township Water System is a private-owned community water system that delivers drinking water to 1,423 residents in Darien, Illinois (DuPage County) through 480 service connections. Its water is drawn from surface water sources. EPA's Safe Drinking Water Information System records 172 total violations for this system , of which 24 (14%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 133 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 Coliform (TCR), recorded in 27 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 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. Statewide, 199 of 487 UCMR5-tested systems have reported PFAS detections (40.9%).

York Township Water System's 172 violations sit above the Illinois 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
1,423
Total Violations
172
Health-Based Violations
24
Water Source
Surface Water

System Details

System Type
Community
Owner Type
Private
Connections
480
County
DuPage
School/Daycare
No
MCL Violations
18
Monitoring Violations
133
Treatment Tech Violations
6

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MR 27 2000
Coliform (TCR) MCL 18 2007
Consumer Confidence Rule Other 10 2025
Lead and Copper Rule MR 9 2012
Lead and Copper Rule TT 6 2009
Public Notice Other 4 2008
Nitrate MR 4 2011
BHC-GAMMA MR 3 1994
Toxaphene MR 3 1994
Carbofuran MR 3 1994
Atrazine MR 3 1994
Heptachlor epoxide MR 3 1994
2,4-D MR 3 1994
Pentachlorophenol MR 3 1994
1,2-DIBROMO-3-CHLOROPROPANE MR 3 1994
Chlordane MR 3 1994
Endothall MR 3 1994
Di(2-ethylhexyl) adipate MR 3 1994
Di(2-ethylhexyl) phthalate MR 3 1994
Picloram MR 3 1994
Aldicarb sulfoxide MR 3 1994
Aldicarb sulfone MR 3 1994
Aldicarb MR 3 1994
Hexachlorocyclopentadiene MR 3 1994
Total Polychlorinated Biphenyls (PCB) MR 3 1994
Dalapon MR 3 1994
ETHYLENE DIBROMIDE MR 3 1994
Benzo(a)pyrene MR 3 1994
Diquat MR 3 1994
Heptachlor MR 3 1994

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 York Township Water System.

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 IL0430010 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 York Township Water System 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 10 SDWIS / IL0430010 / 7000
2012 Lead and Copper Rule MR 9 SDWIS / IL0430010 / 5000
2011 Nitrate MR 4 SDWIS / IL0430010 / 1040
2009 Lead and Copper Rule TT 6 SDWIS / IL0430010 / 5000
2008 Public Notice Other 4 SDWIS / IL0430010 / 7500
2007 Coliform (TCR) MCL 18 SDWIS / IL0430010 / 3100
2000 Coliform (TCR) MR 27 SDWIS / IL0430010 / 3100
1994 BHC-GAMMA MR 3 SDWIS / IL0430010 / 2010
1994 Toxaphene MR 3 SDWIS / IL0430010 / 2020
1994 Carbofuran MR 3 SDWIS / IL0430010 / 2046
1994 Atrazine MR 3 SDWIS / IL0430010 / 2050
1994 Heptachlor epoxide MR 3 SDWIS / IL0430010 / 2067
1994 2,4-D MR 3 SDWIS / IL0430010 / 2105
1994 Pentachlorophenol MR 3 SDWIS / IL0430010 / 2326
1994 1,2-DIBROMO-3-CHLOROPROPANE MR 3 SDWIS / IL0430010 / 2931

How York Township Water System Compares

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

Metric York Township Water System Illinois avg Federal benchmark
Total violations 172 69.4 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 24 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 1,423 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 (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 York Township Water System water safe to drink? ▼
York Township Water System (PWS ID: IL0430010) has 172 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 1,423 people using Surface Water sources.
How many people does York Township Water System serve? ▼
York Township Water System serves 1,423 people in Darien, Illinois. It is a Private-owned system using Surface Water water sources with 480 service connections.
What type of violations does York Township Water System have? ▼
York Township Water System has 172 total violations: 24 health-based violations (MCL exceedances or treatment failures), 133 monitoring/reporting violations, and 6 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in York Township Water System water? ▼
No PFAS testing data is available for York Township Water System under the EPA's UCMR5 monitoring program.
What water source does York Township Water System use? ▼
York Township Water System uses Surface Water 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.

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.