Public water system · IL1970450
ActiveJoliet
At a glance
Joliet (PWSID IL1970450) is an active community water system in Will County, Illinois. It reports serving 160,000 people through 49,000 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, 2 are health-based, and the most recent began in October 2024.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
160,000
Service connections
49,000
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Joliet compare with other water systems in Will County?
By EPA's size categories, Joliet is a very large system (more than 100,000 people). Will County has 236 active public water systems, and Joliet is the largest of them by population served. Its population served is about 61 times the county average of 2,607 people per system, and accounts for 26% of the 615,219 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 Joliet is about 24 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. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 2,808 Illinois systems (73%) list groundwater as their primary source.
Who owns and regulates Joliet?
EPA lists Joliet 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. 34 of the 236 active systems in Will County (14%) are also owned by a local government.
Does Joliet have drinking water violations?
Of the 12 most recent violations in EPA's records, 2 are health-based, and the most recent began in October 2024. The violations listed here began between October 2007 and October 2024. By type: 10 monitoring and reporting, 1 required treatment not met and 1 contaminant level above the legal limit. The contaminant or rule involved most often is Combined Radium (-226 and -228) (4 of them). EPA lists 8 as resolved and 4 as archived. 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. 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 |
|---|---|---|---|---|
| 2024-10-17 | Required treatment not metLSL Inventory · code 2E | Lead and Copper Rule Revisionscode 5200 | Yes | Resolved |
| 2024-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Combined Radium (-226 and -228)code 4010 | No | Resolved |
| 2024-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Combined Radium (-226 and -228)code 4010 | No | Resolved |
| 2023-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Polychlorinated biphenyls (PCBs), totalcode 2383 | No | Archived |
| 2023-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Polychlorinated biphenyls (PCBs), totalcode 2383 | No | Archived |
| 2023-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Polychlorinated biphenyls (PCBs), totalcode 2383 | No | Archived |
| 2023-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Polychlorinated biphenyls (PCBs), totalcode 2383 | No | Archived |
| 2017-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Combined Radium (-226 and -228)code 4010 | No | Resolved |
| 2017-10-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2017-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2017-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2007-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Combined Radium (-226 and -228)code 4010 | Yes | 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.
Joliet: frequently asked questions
Who runs Joliet?
Joliet (PWSID IL1970450) is a community water system owned by a local government. It is regulated by the IL state drinking water program.
How many people does Joliet serve?
Joliet reports serving 160,000 people through 49,000 service connections in Will County, Illinois.
Where does Joliet get its water?
EPA SDWIS lists this system's primary water source as groundwater. Groundwater means the system draws its water from wells or springs fed by underground aquifers.
Does Joliet have any drinking water violations?
Of the 12 most recent violations in EPA's records, 2 are health-based, and the most recent began in October 2024. 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 Joliet's 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, 2 are health-based, and the most recent began in October 2024. For current results, consult the system's annual water quality report, EPA ECHO, or the IL state drinking water program.
Where can I find Joliet's water quality report?
As a community water system, Joliet 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 Will County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Il American-West Suburban | Will | 73,978 | Community | Purchased surface water |
| Romeoville | Will | 50,458 | Community | Groundwater |
| Plainfield | Will | 50,000 | Community | Purchased surface water |
| New Lenox | Will | 27,690 | Community | Purchased surface water |
| Il American-Homer Township | Will | 24,543 | Community | Purchased surface water |
| Frankfort | Will | 24,000 | Community | Groundwater |
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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, “Joliet, PWSID IL1970450, Illinois”, https://aquacensus.com/water-systems/illinois/joliet-il1970450 (data as of October 1, 2026).