Public water system · IL0311290

Active

Hoffman Estates

At a glance

Hoffman Estates (PWSID IL0311290) is an active community water system in Cook County, Illinois. It reports serving 50,179 people through 15,742 service connections. Its primary water source is purchased surface water, and EPA lists it as owned by a local government. EPA's records list 10 violations for this system; 7 are health-based, and the most recent began in March 1994.

Dataset updated October 2026 . Source: EPA SDWIS/ECHO public records.

Population served

50,179

Service connections

15,742

Primary source

SWP

Purchased surface water

System type

CWS

Community water system

System record

PWSIDIL0311290

System typeCommunity water system

Activity statusActive

Population served50,179

Service connections15,742

Primary water sourcePurchased surface water

Owner typeLocal government

Primacy agencyIL state drinking water program

City servedHoffman Estates

StateIllinois

ZIP—

CountyCook County

How does Hoffman Estates compare with other water systems in Cook County?

By EPA's size categories, Hoffman Estates is a large system (10,001 to 100,000 people). Cook County has 251 active public water systems. Its population served is about 139% above the county average of 20,993 people per system, and accounts for 1% 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 Hoffman Estates is about 7.5 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. 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 Hoffman Estates?

EPA lists Hoffman Estates 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 Hoffman Estates have drinking water violations?

EPA's records list 10 violations for this system; 7 are health-based, and the most recent began in March 1994. The violations listed here began between June 1977 and March 1994. By type: 7 contaminant level above the legal limit and 3 monitoring and reporting. The contaminant or rule involved most often is Total coliform bacteria (TCR) (4 of them). EPA lists 8 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
1994-03-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22	Total coliform bacteria (TCR)code 3100	Yes	Archived
1994-03-01	Monitoring and reportingMonitoring, Repeat Minor (TCR) · code 26	Total coliform bacteria (TCR)code 3100	No	Archived
1992-11-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22	Total coliform bacteria (TCR)code 3100	Yes	Archived
1992-11-01	Monitoring and reportingMonitoring, Repeat Minor (TCR) · code 26	Total coliform bacteria (TCR)code 3100	No	Archived
1986-06-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02	Bariumcode 1010	Yes	Resolved
1984-10-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02	Gross alpha (excluding radon and uranium)code 4000	Yes	Resolved
1983-06-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02	Bariumcode 1010	Yes	Archived
1980-10-17	Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02	Gross alpha (excluding radon and uranium)code 4000	Yes	Archived
1980-06-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02	Bariumcode 1010	Yes	Archived
1977-06-30	Monitoring and reportingMonitoring, Regular · code 03	Gross alpha (excluding radon and uranium)code 4000	No	Archived

All 10 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.

Hoffman Estates: frequently asked questions

Who runs Hoffman Estates?

Hoffman Estates (PWSID IL0311290) is a community water system owned by a local government. It is regulated by the IL state drinking water program.

How many people does Hoffman Estates serve?

Hoffman Estates reports serving 50,179 people through 15,742 service connections in Cook County, Illinois.

Where does Hoffman Estates 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 Hoffman Estates have any drinking water violations?

EPA's records list 10 violations for this system; 7 are health-based, and the most recent began in March 1994. 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 Hoffman Estates' 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 10 violations for this system; 7 are health-based, and the most recent began in March 1994. For current results, consult the system's annual water quality report, EPA ECHO, or the IL state drinking water program.

Where can I find Hoffman Estates' water quality report?

As a community water system, Hoffman Estates 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, “Hoffman Estates, PWSID IL0311290, Illinois”, https://aquacensus.com/water-systems/illinois/hoffman-estates-il0311290 (data as of October 1, 2026).