Public water system · IL0312530

Active

Prospect Heights

At a glance

Prospect Heights (PWSID IL0312530) is an active community water system in Cook County, Illinois. It reports serving 2,280 people through 494 service connections. Its primary water source is purchased surface water, and EPA lists it as owned by a local government. EPA's records list 11 violations for this system; 9 are health-based, and the most recent began in January 2025.

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

Population served

2,280

Service connections

494

Primary source

SWP

Purchased surface water

System type

CWS

Community water system

System record

PWSIDIL0312530

System typeCommunity water system

Activity statusActive

Population served2,280

Service connections494

Primary water sourcePurchased surface water

Owner typeLocal government

Primacy agencyIL state drinking water program

City servedProspect Heights

StateIllinois

ZIP—

CountyCook County

How does Prospect Heights compare with other water systems in Cook County?

By EPA's size categories, Prospect Heights is a small system (501 to 3,300 people). Cook County has 251 active public water systems. Its population served is well below the county average of 20,993 people per system, and accounts for less than 0.1% 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 Prospect Heights is about 66% below 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 Prospect Heights?

EPA lists Prospect Heights 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 Prospect Heights have drinking water violations?

EPA's records list 11 violations for this system; 9 are health-based, and the most recent began in January 2025. The violations listed here began between November 1987 and January 2025. By type: 8 contaminant level above the legal limit, 2 monitoring and reporting and 1 required treatment not met. The contaminant or rule involved most often is Combined Radium (-226 and -228) (7 of them). EPA lists 11 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
2025-01-01	Monitoring and reportingMonitoring and Reporting (DBP) · code 27	Total trihalomethanes (TTHM)code 2950	No	Resolved
2010-08-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22	Total coliform bacteria (TCR)code 3100	Yes	Resolved
2003-01-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02	Combined Radium (-226 and -228)code 4010	Yes	Resolved
2002-10-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02	Combined Radium (-226 and -228)code 4010	Yes	Resolved
2001-02-14	Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02	Combined Radium (-226 and -228)code 4010	Yes	Resolved
1999-01-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02	Combined Radium (-226 and -228)code 4010	Yes	Resolved
1998-07-01	Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52	Lead and Copper Rulecode 5000	No	Resolved
1995-01-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02	Combined Radium (-226 and -228)code 4010	Yes	Resolved
1994-01-01	Required treatment not metOCCT/SOWT Study/Recommendation · code 57	Lead and Copper Rulecode 5000	Yes	Resolved
1991-11-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02	Combined Radium (-226 and -228)code 4010	Yes	Resolved
1987-11-30	Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02	Combined Radium (-226 and -228)code 4010	Yes	Resolved

All 11 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.

Prospect Heights: frequently asked questions

Who runs Prospect Heights?

Prospect Heights (PWSID IL0312530) is a community water system owned by a local government. It is regulated by the IL state drinking water program.

How many people does Prospect Heights serve?

Prospect Heights reports serving 2,280 people through 494 service connections in Cook County, Illinois.

Where does Prospect Heights 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 Prospect Heights have any drinking water violations?

EPA's records list 11 violations for this system; 9 are health-based, and the most recent began in January 2025. 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 Prospect Heights' 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 11 violations for this system; 9 are health-based, and the most recent began in January 2025. For current results, consult the system's annual water quality report, EPA ECHO, or the IL state drinking water program.

Where can I find Prospect Heights' water quality report?

As a community water system, Prospect Heights 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, “Prospect Heights, PWSID IL0312530, Illinois”, https://aquacensus.com/water-systems/illinois/prospect-heights-il0312530 (data as of October 1, 2026).