Public water system · IL0314030
ActiveArlington Heights
At a glance
Arlington Heights (PWSID IL0314030) is an active community water system in Cook County, Illinois. It reports serving 73,320 people through 20,539 service connections. Its primary water source is purchased surface water, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in January 2026.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
73,320
Service connections
20,539
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does Arlington Heights compare with other water systems in Cook County?
By EPA's size categories, Arlington Heights is a large system (10,001 to 100,000 people). Cook County has 251 active public water systems, and Arlington Heights is the 5th-largest of them by population served. Its population served is about 3.5 times the county average of 20,993 people per system, and accounts for 1.4% 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 Arlington Heights is about 11 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 Arlington Heights?
EPA lists Arlington 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 Arlington Heights have drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in January 2026. The violations listed here began between January 2024 and January 2026. By type: 9 monitoring and reporting and 3 public notice, recordkeeping or other. The contaminant or rule involved most often is Public Notice (2 of them). EPA lists 9 as resolved and 3 as unaddressed. 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. Unaddressed means the violation is not resolved or archived and is not yet covered by formal enforcement.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2026-01-14 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Unaddressed |
| 2026-01-14 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Unaddressed |
| 2025-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Inadequate Reporting · code 72 | Consumer Confidence Rulecode 7000 | No | Unaddressed |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Vinyl chloridecode 2976 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Ethylbenzenecode 2992 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Dichloromethanecode 2964 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | p-Dichlorobenzenecode 2969 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,2,4-Trichlorobenzenecode 2378 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,1-Dichloroethylenecode 2977 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | trans-1,2-Dichloroethylenecode 2979 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,2-Dichloroethanecode 2980 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Tetrachloroethylenecode 2987 | No | Resolved |
The 12 most recent 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.
Arlington Heights: frequently asked questions
Who runs Arlington Heights?
Arlington Heights (PWSID IL0314030) is a community water system owned by a local government. It is regulated by the IL state drinking water program.
How many people does Arlington Heights serve?
Arlington Heights reports serving 73,320 people through 20,539 service connections in Cook County, Illinois.
Where does Arlington 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 Arlington Heights have any drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in January 2026. 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 Arlington 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. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in January 2026. For current results, consult the system's annual water quality report, EPA ECHO, or the IL state drinking water program.
Where can I find Arlington Heights' water quality report?
As a community water system, Arlington 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 |
| Palatine | Cook | 70,875 | Community | Purchased surface water |
| Skokie | Cook | 66,422 | 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, “Arlington Heights, PWSID IL0314030, Illinois”, https://aquacensus.com/water-systems/illinois/arlington-heights-il0314030 (data as of October 1, 2026).