Rock City - Stp, Village Of
Rock City, IL · Stephenson County · Publicly Owned Treatment Works
- Average flow
- 0.02 MGD
- Design flow
- 0.1 MGD
- NPDES permit
- ILG580267
- Effective
- Permit expires
- May 2027
- Population served
- 258
- CWNS 2022
Rock City - Stp, Village Of is a publicly owned wastewater treatment works in Rock City, Stephenson County, Illinois treating an average of 0.02 million gallons per day against a permitted design capacity of 0.1 MGD, serving about 258 residents. Treatment on site includes uncovered lagoons. It discharges under NPDES permit ILG580267 (effective), which expires in May 2027, with 6 recorded violations in the last three years.
Treatment technology
Treatment structures identified at this facility. Exact unit counts are available in Klarifi.
Uncovered lagoons
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Compliance snapshot (last 3 years)
- Total violations
- 6
- Effluent violations
- 6
Based on NPDES Discharge Monitoring Reports. Full violation history, parameters and discharge data available in the Klarifi platform.
Key contacts
Decision-makers at Rock City - Stp, Village Of.
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Durand · 8 mi away
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Pecatonica · 9 mi away
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Cedarville · 10 mi away
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Seward · 13 mi away
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German Valley · 14 mi away
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Winslow · 18 mi away
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Rock City - Stp, Village Of: frequently asked questions
Sources and methodology
Flow, permit and violation figures come from the EPA's ICIS-NPDES discharge monitoring records. Population served comes from the Clean Watersheds Needs Survey 2022. Treatment structures are identified by Klarifi's review of aerial imagery, and capital improvement projects are extracted from published municipal budget documents. Violations are counted over the last three years of monitoring reports.
Data refreshed September 11, 2026; facility record last updated March 7, 2025.