St Tammany Parish-Cross Gate
Slidell, LA · St. Tammany County · Publicly Owned Treatment Works
- Average flow
- 0.45 MGD
- Design flow
- 1 MGD
- NPDES permit
- LA0048941
- Effective
- Permit expires
- June 2030
- Population served
- 7,435
- CWNS 2022
St Tammany Parish-Cross Gate is a publicly owned wastewater treatment plant in Slidell, St. Tammany County, Louisiana treating an average of 0.45 million gallons per day against a permitted design capacity of 1 MGD, serving about 7,435 residents. It discharges under NPDES permit LA0048941 (effective), which expires in June 2030, with 52 recorded violations in the last three years.
Treatment technology
Treatment structures identified at this facility. Exact unit counts are available in Klarifi.
Treatment structure data not yet analyzed for this facility.
Compliance snapshot (last 3 years)
- Total violations
- 52
- Effluent violations
- 14
Based on NPDES Discharge Monitoring Reports. Full violation history, parameters and discharge data available in the Klarifi platform.
Key contacts
Decision-makers at St Tammany Parish-Cross Gate.
No verified contacts on file yet
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Nearby wastewater treatment plants in Louisiana
Slidell · 4 mi away
2.95 MGD
Pearl River · 6 mi away
0.14 MGD
Mandeville · 18 mi away
0.04 MGD
Mandeville · 18 mi away
0.48 MGD
Mandeville · 21 mi away
0.03 MGD
Mandeville · 22 mi away
0.37 MGD
Covington · 23 mi away
0.12 MGD
Mandeville · 23 mi away
0.3 MGD
St Tammany Parish-Cross Gate: 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 January 28, 2025.