St Tammany Parish-Cross Gate
Slidell, LA 70461 · St. Tammany County · Publicly Owned Treatment Works
- Average flow
- 0.53 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 0.53 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 51 recorded violations in the last three years. EPA has recorded 1 formal enforcement action naming the plant, the latest in April 2026.
Treatment technology
Treatment structures and unit processes at St Tammany Parish-Cross Gate.
Treatment structure data not yet analyzed for this facility.
Compliance snapshot (last 3 years)
- Total violations
- 51
- Effluent violations
- 13
Based on NPDES Discharge Monitoring Reports. Full violation history, parameters and discharge data available in the Klarifi platform.
EPA enforcement history
Federal civil enforcement cases, compliance inspections and informal actions recorded for St Tammany Parish-Cross Gate in EPA's ICIS system.
- Formal actions
- 1
- 1 since FY2020
- EPA inspections
- 0
- none on record
Latest case · Apr 2026
Cross Gates Wastewater Treatment Plant Administrative Order
Administrative order · CWA, NPDES Permit Violations · Final Order Issued
EPA's description of the case:
“St. Tammany Parish - Cross Gates Wastewater Treatment Facility, has been issued an Administrative Order following an inspection made by the Environmental Protection Agency. The violations alleged are…”
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Source: EPA ECHO, civil enforcement case 06-2026-1770.
Full case history with a free Klarifi account
Every action against St Tammany Parish-Cross Gate with dates, milestones, violation types and EPA's complete case summaries, plus inspections and informal actions.
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
3.47 MGD
Pearl River · 6 mi away
0.14 MGD
Mandeville · 18 mi away
0.05 MGD
Mandeville · 18 mi away
0.59 MGD
Mandeville · 21 mi away
0.02 MGD
Mandeville · 22 mi away
0.45 MGD
Mandeville · 23 mi away
1.64 MGD
Covington · 23 mi away
0.16 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 October 26, 2026; facility record last updated January 28, 2025.
Wastewater terms: POTW · MGD · NPDES permit · Inflow and infiltration · FOG · Equalization tank · all terms