Public water system · IL0311200
ActiveHickory Hills
At a glance
Hickory Hills (PWSID IL0311200) is an active community water system in Cook County, Illinois. It reports serving 14,505 people through 4,069 service connections. Its primary water source is purchased surface water, and EPA lists it as owned by a local government. EPA's records list 3 violations for this system; 1 is health-based, and the most recent began in October 1992.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
14,505
Service connections
4,069
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does Hickory Hills compare with other water systems in Cook County?
By EPA's size categories, Hickory Hills is a large system (10,001 to 100,000 people). Cook County has 251 active public water systems. Its population served is about 31% below the county average of 20,993 people per system, and accounts for 0.3% 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 Hickory Hills is about twice 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 Hickory Hills?
EPA lists Hickory 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 Hickory Hills have drinking water violations?
EPA's records list 3 violations for this system; 1 is health-based, and the most recent began in October 1992. The violations listed here began between January 1992 and October 1992. By type: 2 monitoring and reporting 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 3 as archived. 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.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 1992-10-01 | Monitoring and reportingMonitoring, Repeat Major (TCR) · code 25 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1992-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
| 1992-01-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Archived |
All 3 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.
Hickory Hills: frequently asked questions
Who runs Hickory Hills?
Hickory Hills (PWSID IL0311200) is a community water system owned by a local government. It is regulated by the IL state drinking water program.
How many people does Hickory Hills serve?
Hickory Hills reports serving 14,505 people through 4,069 service connections in Cook County, Illinois.
Where does Hickory 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 Hickory Hills have any drinking water violations?
EPA's records list 3 violations for this system; 1 is health-based, and the most recent began in October 1992. 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 Hickory 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 3 violations for this system; 1 is health-based, and the most recent began in October 1992. For current results, consult the system's annual water quality report, EPA ECHO, or the IL state drinking water program.
Where can I find Hickory Hills' water quality report?
As a community water system, Hickory 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 |
Related pages
Working with water-system records? Pro adds alerts, change history and CSV export ($49/mo); Enterprise adds full national files, the API and an MCP server for AI tools.
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, “Hickory Hills, PWSID IL0311200, Illinois”, https://aquacensus.com/water-systems/illinois/hickory-hills-il0311200 (data as of October 1, 2026).