City Of Waterloo STP 3
1011 Sherwood Lane, Waterloo, IL 62298 · Monroe County · Publicly Owned Treatment Works
- Average flow
- 0.93 MGD
- Design flow
- 3.13 MGD
- NPDES permit
- IL0077551
- Effective
- Permit expires
- December 2030
- Population served
- 10,536
- CWNS 2022
City Of Waterloo STP 3 is a publicly owned wastewater treatment works in Waterloo, Monroe County, Illinois treating an average of 0.93 million gallons per day against a permitted design capacity of 3.13 MGD, serving about 10,536 residents. It discharges under NPDES permit IL0077551 (effective), which expires in December 2030, with 4 recorded violations in the last three years.
Treatment technology
2 treatment structures and unit processes identified at City Of Waterloo STP 3.
Available with a free Klarifi account
See the full treatment train at City Of Waterloo STP 3: structures, unit processes and planned upgrades, with exact unit counts.
Compliance snapshot (last 3 years)
- Total violations
- 4
- Effluent violations
- 4
Based on NPDES Discharge Monitoring Reports. Full violation history, parameters and discharge data available in the Klarifi platform.
Key contacts
18 verified contacts for City Of Waterloo STP 3, with validated emails and direct phone numbers.
Unlock 18 verified contacts (15 more than shown)
Names, validated emails and direct phone numbers for decision-makers at City Of Waterloo STP 3, plus the full compliance history and discharge data.
Nearby wastewater treatment plants in Illinois
Millstadt · 7 mi away
0.34 MGD
Hecker · 8 mi away
0.0051 MGD
Smithton · 9 mi away
0.37 MGD
Maeystown · 11 mi away
0.0044 MGD
Valmeyer · 11 mi away
0.03 MGD
Freeburg · 12 mi away
0.33 MGD
Red Bud · 12 mi away
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Dupo · 13 mi away
0.33 MGD
City Of Waterloo STP 3: 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 October 26, 2026; facility record last updated March 16, 2025.
Wastewater terms: POTW · MGD · NPDES permit · Inflow and infiltration · Activated sludge · Oxidation ditch · all terms