St. Tammany Parish Government - Castine Regional Sewage Treatment Plant
End Of Lapin Street, Mandeville, LA 70448 · St. Tammany County · Publicly Owned Treatment Works
- Average flow
- 0.59 MGD
- Design flow
- 1 MGD
- NPDES permit
- LA0120154
- Effective
- Permit expires
- August 2028
- Population served
- —
- CWNS 2022
St. Tammany Parish Government - Castine Regional Sewage Treatment Plant is a publicly owned wastewater treatment works in Mandeville, St. Tammany County, Louisiana treating an average of 0.59 million gallons per day against a permitted design capacity of 1 MGD. It discharges under NPDES permit LA0120154 (effective), which expires in August 2028, with 16 recorded violations in the last three years.
Treatment technology
Treatment structures and unit processes at St. Tammany Parish Government - Castine Regional Sewage Treatment Plant.
Treatment structure data not yet analyzed for this facility.
Compliance snapshot (last 3 years)
- Total violations
- 16
- Effluent violations
- 16
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 Government - Castine Regional Sewage Treatment Plant.
No verified contacts on file yet
Klarifi verifies plant and municipal decision-makers continuously. Start a free trial to browse contacts at nearby plants and flag this one for verification.
Nearby wastewater treatment plants in Louisiana
Mandeville · 2 mi away
0.05 MGD
Mandeville · 4 mi away
0.45 MGD
Mandeville · 5 mi away
1.64 MGD
Mandeville · 5 mi away
0.24 MGD
Covington · 5 mi away
0.16 MGD
Mandeville · 6 mi away
0.02 MGD
Covington · 6 mi away
0.17 MGD
Madisonville · 8 mi away
0.2 MGD
St. Tammany Parish Government - Castine Regional Sewage Treatment Plant: 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 February 27, 2025.
Wastewater terms: POTW · MGD · NPDES permit · Inflow and infiltration · Tertiary treatment · Significant industrial user · all terms