Public water system · IL0430250
ActiveClarendon Hills
At a glance
Clarendon Hills (PWSID IL0430250) is an active community water system in DuPage County, Illinois. It reports serving 8,702 people through 2,742 service connections. Its primary water source is purchased surface water, and EPA lists it as owned by a local government. EPA's records list 7 violations for this system; 1 is health-based, and the most recent began in January 2023.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
8,702
Service connections
2,742
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does Clarendon Hills compare with other water systems in DuPage County?
By EPA's size categories, Clarendon Hills is a medium system (3,301 to 10,000 people). DuPage County has 125 active public water systems. Its population served is about 27% above the county average of 6,865 people per system, and accounts for 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 Clarendon Hills is about 30% 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 Clarendon Hills?
EPA lists Clarendon Hills 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 Clarendon Hills have drinking water violations?
EPA's records list 7 violations for this system; 1 is health-based, and the most recent began in January 2023. The violations listed here began between June 1977 and January 2023. By type: 5 monitoring and reporting, 1 public notice, recordkeeping or other and 1 contaminant level above the legal limit. The contaminant or rule involved most often is Total coliform bacteria (TCR) (3 of them). EPA lists 5 as archived and 2 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 |
|---|---|---|---|---|
| 2023-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Combined Radium (-226 and -228)code 4010 | No | Archived |
| 2020-12-30 | Monitoring and reportingLead Consumer Notice · code 66 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2017-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Inadequate Reporting · code 72 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2000-09-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1996-08-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1992-09-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
| 1977-06-30 | Monitoring and reportingMonitoring, Regular · code 03 | Gross alpha (excluding radon and uranium)code 4000 | No | Archived |
All 7 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.
Clarendon Hills: frequently asked questions
Who runs Clarendon Hills?
Clarendon Hills (PWSID IL0430250) is a community water system owned by a local government. It is regulated by the IL state drinking water program.
How many people does Clarendon Hills serve?
Clarendon Hills reports serving 8,702 people through 2,742 service connections in DuPage County, Illinois.
Where does Clarendon Hills 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 Clarendon Hills have any drinking water violations?
EPA's records list 7 violations for this system; 1 is health-based, and the most recent began in January 2023. 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 Clarendon Hills' 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. EPA's records list 7 violations for this system; 1 is health-based, and the most recent began in January 2023. For current results, consult the system's annual water quality report, EPA ECHO, or the IL state drinking water program.
Where can I find Clarendon Hills' water quality report?
As a community water system, Clarendon Hills 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, “Clarendon Hills, PWSID IL0430250, Illinois”, https://aquacensus.com/water-systems/illinois/clarendon-hills-il0430250 (data as of October 1, 2026).