Public water system · IL0430900
ActiveWest Chicago
At a glance
West Chicago (PWSID IL0430900) is an active community water system in DuPage County, Illinois. It reports serving 25,166 people through 6,869 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, 10 are health-based, and the most recent began in October 2005.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
25,166
Service connections
6,869
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does West Chicago compare with other water systems in DuPage County?
By EPA's size categories, West Chicago is a large system (10,001 to 100,000 people). DuPage County has 125 active public water systems. Its population served is about 3.7 times the county average of 6,865 people per system, and accounts for 2.9% 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 West Chicago is about 3.8 times 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. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 2,808 Illinois systems (73%) list groundwater as their primary source.
Who owns and regulates West Chicago?
EPA lists West Chicago 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 West Chicago have drinking water violations?
Of the 12 most recent violations in EPA's records, 10 are health-based, and the most recent began in October 2005. The violations listed here began between July 2004 and October 2005. By type: 10 contaminant level above the legal limit and 2 public notice, recordkeeping or other. The contaminant or rule involved most often is Combined Radium (-226 and -228) (6 of them). EPA lists 12 as resolved. 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 |
|---|---|---|---|---|
| 2005-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Gross alpha (excluding radon and uranium)code 4000 | Yes | Resolved |
| 2005-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Combined Radium (-226 and -228)code 4010 | Yes | Resolved |
| 2005-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Gross alpha (excluding radon and uranium)code 4000 | Yes | Resolved |
| 2005-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Combined Radium (-226 and -228)code 4010 | Yes | Resolved |
| 2005-04-08 | Public notice, recordkeeping or otherPublic Notification Violation without NPDWR Violation · code 76 | Public Noticecode 7500 | No | Resolved |
| 2005-04-08 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Resolved |
| 2005-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Combined Radium (-226 and -228)code 4010 | Yes | Resolved |
| 2005-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Gross alpha (excluding radon and uranium)code 4000 | Yes | Resolved |
| 2005-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Gross alpha (excluding radon and uranium)code 4000 | Yes | Resolved |
| 2005-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Combined Radium (-226 and -228)code 4010 | Yes | Resolved |
| 2004-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Combined Radium (-226 and -228)code 4010 | Yes | Resolved |
| 2004-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Combined Radium (-226 and -228)code 4010 | Yes | Resolved |
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.
West Chicago: frequently asked questions
Who runs West Chicago?
West Chicago (PWSID IL0430900) is a community water system owned by a local government. It is regulated by the IL state drinking water program.
How many people does West Chicago serve?
West Chicago reports serving 25,166 people through 6,869 service connections in DuPage County, Illinois.
Where does West Chicago get its water?
EPA SDWIS lists this system's primary water source as groundwater. Groundwater means the system draws its water from wells or springs fed by underground aquifers.
Does West Chicago have any drinking water violations?
Of the 12 most recent violations in EPA's records, 10 are health-based, and the most recent began in October 2005. 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 West Chicago'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, 10 are health-based, and the most recent began in October 2005. For current results, consult the system's annual water quality report, EPA ECHO, or the IL state drinking water program.
Where can I find West Chicago's water quality report?
As a community water system, West Chicago 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, “West Chicago, PWSID IL0430900, Illinois”, https://aquacensus.com/water-systems/illinois/west-chicago-il0430900 (data as of October 1, 2026).