Public water system · IL1770500
ActiveRock City
At a glance
Rock City (PWSID IL1770500) is an active community water system in Stephenson County, Illinois. It reports serving 293 people through 128 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. EPA's records list 7 violations for this system; 1 is health-based, and the most recent began in July 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
293
Service connections
128
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Rock City compare with other water systems in Stephenson County?
By EPA's size categories, Rock City is a very small system (500 people or fewer). Stephenson County has 42 active public water systems. Its population served is about 64% below the county average of 811 people per system, and accounts for 0.9% of the 34,049 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 Rock City 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 Rock City?
EPA lists Rock City 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 42 active systems in Stephenson County (24%) are also owned by a local government.
Does Rock City have drinking water violations?
EPA's records list 7 violations for this system; 1 is health-based, and the most recent began in July 2025. The violations listed here began between June 1977 and July 2025. By type: 5 monitoring and reporting, 1 public notice, recordkeeping or other and 1 contaminant level above the legal limit. The contaminant or rule involved most often is Lead and Copper Rule (2 of them). EPA lists 4 as resolved and 3 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 |
|---|---|---|---|---|
| 2025-07-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2023-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 2015-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2011-01-02 | Monitoring and reportingLead Consumer Notice · code 66 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2003-07-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 2000-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
| 1977-06-30 | Monitoring and reportingMonitoring, Regular · code 03 | Gross alpha (excluding radon and uranium)code 4000 | No | Archived |
All 7 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.
Rock City: frequently asked questions
Who runs Rock City?
Rock City (PWSID IL1770500) is a community water system owned by a local government. It is regulated by the IL state drinking water program.
How many people does Rock City serve?
Rock City reports serving 293 people through 128 service connections in Stephenson County, Illinois.
Where does Rock City 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 Rock City have any drinking water violations?
EPA's records list 7 violations for this system; 1 is health-based, and the most recent began in July 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 Rock City'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. EPA's records list 7 violations for this system; 1 is health-based, and the most recent began in July 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 Rock City's water quality report?
As a community water system, Rock City 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 Stephenson County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Freeport | Stephenson | 23,930 | Community | Groundwater |
| Lena | Stephenson | 2,680 | Community | Groundwater |
| Pearl City | Stephenson | 790 | Community | Groundwater |
| Orangeville | Stephenson | 780 | Community | Groundwater |
| Cedarville | Stephenson | 663 | Community | Groundwater |
| Prairie Path Water Company-Northern Hill | Stephenson | 600 | 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, “Rock City, PWSID IL1770500, Illinois”, https://aquacensus.com/water-systems/illinois/rock-city-il1770500 (data as of October 1, 2026).