Rock City
EPA ID: IL1770500 · 313 people served · 2 ZIP codes
Looking at the EPA enforcement file for Rock City, 1 violation are listed as unresolved — those findings cover the utility's service area of approximately 313 people and remain open in the federal compliance system, awaiting formal corrective action documentation.
Data: EPA SDWIS Last verified: 2026-04-02
Service Area Map
Coverage area for Rock City Source: EPA SDWIS service area boundaries.
Service area boundary — Grade F
Service Area Demographics
The Rock City serves a community with a median household income of $91,804 and an estimated 4,666 residents across its service area. Approximately 69% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
Environmental Justice Note: 31% of the population in this service area is classified as disadvantaged under EPA's EJScreen criteria. Communities with higher disadvantaged populations often face disproportionate environmental and health burdens, including aging water infrastructure and limited resources for remediation.
💧 Where Does Your Water Come From?
Rock City's water is pumped from underground aquifers. Groundwater is naturally filtered through rock and soil, but it can be vulnerable to PFAS contamination, nitrates from agriculture, and industrial chemicals that seep into the water table.
About 1% of homes in Stephenson County, Illinois rely on private wells rather than public water systems. Private well owners are responsible for their own water testing and treatment.
Wastewater Proximity Note: This service area ranks in the 60th percentile nationally for proximity to wastewater discharge points.
Infrastructure Risk
Detected Contaminants
How Rock City compares to EPA limits
What This Means For You
Stage 1 DBP Rule at 1 mg/L exceeds the EPA maximum of mg/L.
Revised Total Coliform Rule at 1 presence exceeds the EPA maximum of presence.
Comparable Water Systems
Similar-sized systems in Illinois
Estimated Remediation Costs
Average estimated costs across ZIP codes served by this system
Based on national averages for common remediation projects. Actual costs vary by property. Only issues flagged by EPA, FEMA, or state data for each ZIP code are included.
System Overview
Rock City (EPA ID: IL1770500) is a community water system in Illinois that serves approximately 313 people from groundwater sources.
This system provides water to 2 ZIP codes across 2 communities.
Average Home Safety Score: F (31/100)
Based on water quality violations, lead levels, and radon risk across all ZIP codes served by this system.
Violation History
Recent Violations
| Date | Contaminant | Type | Status |
|---|---|---|---|
| July 1, 2025 | Stage 1 DBP Rule | Monitoring | Unresolved |
| July 1, 2023 | Revised Total Coliform Rule | Monitoring | Resolved |
Contaminants Detected
The following contaminants have been flagged in EPA records for this water system:
| Contaminant | Category | Violations | Health-Based |
|---|---|---|---|
| Stage 1 DBP Rule | Treatment Failure | 1 | No |
| Revised Total Coliform Rule | Microbiological | 1 | No |
Lead & Copper
EPA Lead and Copper Rule sampling data for ZIP codes served by this system:
| ZIP Code | Lead Level | Exceeds Limit | Sample Date |
|---|---|---|---|
| 61070 | 0.01695 mg/L | Yes | N/A |
Radon Risk in Service Area
Dominant radon zone for ZIP codes served by this system: Zone 1 (High Risk)
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
Need help with your water quality?
Typical cost: Water test: typically $20–$50 (DIY kit) · Professional inspection: $150–$400
Find the Right Water FilterFree tip: Let cold water run for 2 minutes before drinking — this helps flush lead from your pipes.
ZIP Codes Served
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Rock City (IL1770500) on EPA.gov.
Frequently Asked Questions
Is Rock City water safe to drink?
Rock City has only monitoring/reporting violations, which are procedural in nature. The system meets federal health-based standards.
How many people does Rock City serve?
Rock City serves approximately 313 people across 2 ZIP codes in Illinois.
Where does Rock City get its water?
The primary water source is groundwater.
Lead Service Line Inventory
Service line breakdown reported under the federal Lead and Copper Rule Improvements (LCRI) inventory requirement:
Federal LCRI rule (effective October 2024) requires every public water system to inventory its service lines and complete lead-line replacement within 10 years.
Source: EPA SDWIS Federal Service Line Inventory (Phase 2) · Submitted 2026
ZipCheckup is not affiliated with the utility or state agency. Inventory figures render verbatim from the public LCRI submission cited above; ZipCheckup does not perform inspections or replacements.
Frequently Asked Questions
What You Can Do
Test your water
Home test kits can detect lead, bacteria, and other contaminants at your tap. Find the right filter →
Check your specific ZIP code
Water quality can vary within a system. View nearest ZIP report →
Contact your utility
Rock City (EPA ID: IL1770500) — request the latest Consumer Confidence Report or ask about specific contaminants.