Public water system · IL0431150
ActiveWinfield
At a glance
Winfield (PWSID IL0431150) is an active community water system in DuPage County, Illinois. It reports serving 9,835 people through 3,830 service connections. Its primary water source is purchased surface water, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in December 2020.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
9,835
Service connections
3,830
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does Winfield compare with other water systems in DuPage County?
By EPA's size categories, Winfield is a medium system (3,301 to 10,000 people). DuPage County has 125 active public water systems. Its population served is about 43% above the county average of 6,865 people per system, and accounts for 1.1% of the 858,100 people reported by systems filed under the county. Across Illinois, the 3,872 active systems average 3,204 people each. Nationally, the average active community water system reports serving 6,703 people, so Winfield is about 47% above that figure.
What does “community water system” mean?
A community water system serves at least 15 connections used by year-round residents, or regularly serves at least 25 year-round residents. Homes, apartments and mobile-home parks are served by these. Illinois has 1,773 active community water systems, 46% of the state's 3,872 active systems. Purchased surface water means the system buys surface water from another public water system rather than drawing its own. 619 Illinois systems (16%) list purchased surface water as their primary source.
Who owns and regulates Winfield?
EPA lists Winfield as owned by a local government. The IL state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 32 of the 125 active systems in DuPage County (26%) are also owned by a local government.
Does Winfield have drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in December 2020. The violations listed here began between March 1994 and December 2020. By type: 11 monitoring and reporting and 1 contaminant level above the legal limit. The contaminant or rule involved most often is Total coliform bacteria (TCR) (9 of them). EPA lists 11 as archived and 1 as resolved. Archived means the violation was not marked resolved but is more than five years past the end of the noncompliance period, so it no longer counts toward current compliance status. Resolved means at least one resolving action is on record: the system returned to compliance, the rule no longer applies, or no further action was needed.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2020-12-30 | Monitoring and reportingLead Consumer Notice · code 66 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2001-07-01 | Monitoring and reportingMonitoring, Repeat Minor (TCR) · code 26 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1999-06-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1999-05-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1999-04-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1999-03-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1997-04-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1997-03-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1995-12-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1994-04-01 | Monitoring and reportingMonitoring, Regular · code 03 | Combined Radium (-226 and -228)code 4010 | No | Archived |
| 1994-04-01 | Monitoring and reportingMonitoring, Regular · code 03 | Gross alpha (excluding radon and uranium)code 4000 | No | Archived |
| 1994-03-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
The 12 most recent violations in EPA's records, newest first.Labels and codes come from EPA's SDWIS reference tables. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found. "Health-based" marks violations of a legal limit or required treatment.
Winfield: frequently asked questions
Who runs Winfield?
Winfield (PWSID IL0431150) is a community water system owned by a local government. It is regulated by the IL state drinking water program.
How many people does Winfield serve?
Winfield reports serving 9,835 people through 3,830 service connections in DuPage County, Illinois.
Where does Winfield get its water?
EPA SDWIS lists this system's primary water source as purchased surface water. Purchased surface water means the system buys surface water from another public water system rather than drawing its own.
Does Winfield have any drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in December 2020. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found.
Is Winfield's water safe to drink?
AquaCensus shows EPA compliance records, not current water test results, so it cannot say whether the water is safe at a given moment. Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in December 2020. For current results, consult the system's annual water quality report, EPA ECHO, or the IL state drinking water program.
Where can I find Winfield's water quality report?
As a community water system, Winfield must deliver an annual water quality report, called a Consumer Confidence Report, to its customers by July 1 each year, covering the previous calendar year. The system can provide a copy on request.
Other water systems in DuPage County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Naperville | DuPage | 156,406 | Community | Purchased surface water |
| Wheaton | DuPage | 53,970 | Community | Purchased surface water |
| Downers Grove | DuPage | 49,425 | Community | Purchased surface water |
| Elmhurst | DuPage | 45,000 | Community | Purchased surface water |
| Lombard | DuPage | 44,476 | Community | Purchased surface water |
| Carol Stream | DuPage | 39,854 | Community | Purchased surface water |
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About this data
Source: U.S. EPA Safe Drinking Water Information System (SDWIS) and SDWA violation records, via EPA ECHO, as published October 1, 2026 — AquaCensus refreshes it quarterly. See the methodology for how records are matched, cleaned and scored.
Cite as: AquaCensus, “Winfield, PWSID IL0431150, Illinois”, https://aquacensus.com/water-systems/illinois/winfield-il0431150 (data as of October 1, 2026).