Public water system · IL0312400
ActivePalos Hills
At a glance
Palos Hills (PWSID IL0312400) is an active community water system in Cook County, Illinois. It reports serving 18,530 people through 6,500 service connections. Its primary water source is purchased surface water, and EPA lists it as owned by a local government. EPA's records list 5 violations for this system; 3 are health-based, and the most recent began in December 2020.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
18,530
Service connections
6,500
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does Palos Hills compare with other water systems in Cook County?
By EPA's size categories, Palos Hills is a large system (10,001 to 100,000 people). Cook County has 251 active public water systems. Its population served is about 12% below the county average of 20,993 people per system, and accounts for 0.4% of the 5,269,212 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 Palos Hills is about 176% 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 Palos Hills?
EPA lists Palos 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. 134 of the 251 active systems in Cook County (53%) are also owned by a local government.
Does Palos Hills have drinking water violations?
EPA's records list 5 violations for this system; 3 are health-based, and the most recent began in December 2020. The violations listed here began between August 1992 and December 2020. By type: 3 contaminant level above the legal limit and 2 monitoring and reporting. The contaminant or rule involved most often is Total coliform bacteria (TCR) (4 of them). EPA lists 4 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 |
| 2000-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
| 1992-08-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
| 1992-08-01 | Monitoring and reportingMonitoring, Repeat Major (TCR) · code 25 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1992-08-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Acute (TCR) · code 21 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
All 5 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.
Palos Hills: frequently asked questions
Who runs Palos Hills?
Palos Hills (PWSID IL0312400) is a community water system owned by a local government. It is regulated by the IL state drinking water program.
How many people does Palos Hills serve?
Palos Hills reports serving 18,530 people through 6,500 service connections in Cook County, Illinois.
Where does Palos 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 Palos Hills have any drinking water violations?
EPA's records list 5 violations for this system; 3 are 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 Palos 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 5 violations for this system; 3 are 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 Palos Hills' water quality report?
As a community water system, Palos 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 Cook County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Chicago | Cook | 2,721,308 | Community | Surface water |
| Cicero | Cook | 83,000 | Community | Purchased surface water |
| Schaumburg | Cook | 75,750 | Community | Purchased surface water |
| Evanston | Cook | 74,486 | Community | Surface water |
| Arlington Heights | Cook | 73,320 | Community | Purchased surface water |
| Palatine | Cook | 70,875 | 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, “Palos Hills, PWSID IL0312400, Illinois”, https://aquacensus.com/water-systems/illinois/palos-hills-il0312400 (data as of October 1, 2026).