Public water system · IL0850450
ActiveStockton
At a glance
Stockton (PWSID IL0850450) is an active community water system in Jo Daviess County, Illinois. It reports serving 1,728 people through 874 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, one is health-based, and the most recent began in January 2026.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
1,728
Service connections
874
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Stockton compare with other water systems in Jo Daviess County?
By EPA's size categories, Stockton is a small system (501 to 3,300 people). Jo Daviess County has 41 active public water systems, and Stockton is the 3rd-largest of them by population served. Its population served is about 4 times the county average of 435 people per system, and accounts for 9.7% of the 17,828 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 Stockton is well 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. 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 Stockton?
EPA lists Stockton 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. 10 of the 41 active systems in Jo Daviess County (24%) are also owned by a local government.
Does Stockton have drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in January 2026. The violations listed here began between July 1992 and January 2026. By type: 11 monitoring and reporting and 1 contaminant level above the legal limit. The contaminant or rule involved most often is Combined Radium (-226 and -228) (2 of them). EPA lists 10 as resolved and 2 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 |
|---|---|---|---|---|
| 2026-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Combined Radium (-226 and -228)code 4010 | Yes | Archived |
| 2022-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Combined Radium (-226 and -228)code 4010 | No | Resolved |
| 1994-01-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1992-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Xylenes, Totalcode 2955 | No | Resolved |
| 1992-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | cis-1,2-Dichloroethylenecode 2380 | No | Resolved |
| 1992-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Benzenecode 2990 | No | Resolved |
| 1992-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Carbon tetrachloridecode 2982 | No | Resolved |
| 1992-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,2-Dichloropropanecode 2983 | No | Resolved |
| 1992-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,1,1-Trichloroethanecode 2981 | No | Resolved |
| 1992-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Styrenecode 2996 | No | Resolved |
| 1992-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | o-Dichlorobenzenecode 2968 | No | Resolved |
| 1992-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | p-Dichlorobenzenecode 2969 | 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.
Stockton: frequently asked questions
Who runs Stockton?
Stockton (PWSID IL0850450) is a community water system owned by a local government. It is regulated by the IL state drinking water program.
How many people does Stockton serve?
Stockton reports serving 1,728 people through 874 service connections in Jo Daviess County, Illinois.
Where does Stockton 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 Stockton have any drinking water violations?
Of the 12 most recent violations in EPA's records, one 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 Stockton'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, one 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 Stockton's water quality report?
As a community water system, Stockton 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 Jo Daviess County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Galena | Jo Daviess | 3,308 | Community | Groundwater |
| Prairie Path Water Company-Galena | Jo Daviess | 2,294 | Community | Groundwater |
| East Dubuque | Jo Daviess | 1,565 | Community | Groundwater |
| Warren | Jo Daviess | 1,323 | Community | Groundwater |
| Prairie Path Water Company-Apple Canyon | Jo Daviess | 931 | Community | Groundwater |
| Hanover | Jo Daviess | 863 | 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, “Stockton, PWSID IL0850450, Illinois”, https://aquacensus.com/water-systems/illinois/stockton-il0850450 (data as of October 1, 2026).