Alexis STP
Alexis, IL · Mercer County · Publicly Owned Treatment Works
- Average flow
- 0.04 MGD
- Design flow
- 0.36 MGD
- NPDES permit
- IL0021211
- Effective
- Permit expires
- January 2028
- Population served
- 839
- CWNS 2022
Alexis STP is a publicly owned wastewater treatment works in Alexis, Mercer County, Illinois treating an average of 0.04 million gallons per day against a permitted design capacity of 0.36 MGD, serving about 839 residents. Treatment on site includes clarifiers, uncovered lagoons, biogas balloons. It discharges under NPDES permit IL0021211 (effective), which expires in January 2028, with 172 recorded violations in the last three years.
Treatment technology
Treatment structures identified at this facility. Exact unit counts are available in Klarifi.
Compliance snapshot (last 3 years)
- Total violations
- 172
- Effluent violations
- 172
Based on NPDES Discharge Monitoring Reports. Full violation history, parameters and discharge data available in the Klarifi platform.
Key contacts
1 verified contact for Alexis STP, with validated emails and direct phone numbers.
Unlock 1 verified contact
Names, validated emails and direct phone numbers for decision-makers at Alexis STP, plus the full compliance history and discharge data.
Nearby wastewater treatment plants in Illinois
Monmouth · 9 mi away
2.64 MGD
Monmouth · 10 mi away
—
Viola · 11 mi away
0.03 MGD
Galesburg · 11 mi away
3.22 MGD
New Windsor · 12 mi away
0.009 MGD
Alpha · 13 mi away
0.005 MGD
Matherville · 13 mi away
—
Aledo · 13 mi away
0.15 MGD
Alexis STP: 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 November 7, 2025.