Louisiana Wastewater Treatment Plants
Last Updated: October 2023
1. Introduction
Louisiana’s wastewater infrastructure operates within one of the most hydro-geologically complex environments in the United States. Managing treatment capacity in a state defined by high water tables, subsidence, and significant industrial activity presents unique challenges for utility managers and consulting engineers. The state’s infrastructure is overseen by the Louisiana Department of Environmental Quality (LDEQ) and is heavily influenced by the need for resilience against tropical weather events.
Currently, Louisiana manages a mix of large regional facilities in metropolitan hubs like New Orleans, Baton Rouge, and Shreveport, alongside a fragmented network of smaller parish-level systems. A significant driver of recent capital investment has been federal consent decrees aimed at reducing sanitary sewer overflows (SSOs) caused by aging infrastructure and heavy inflow and infiltration (I/I). With the influx of funding from the Infrastructure Investment and Jobs Act (IIJA) and aggressive State Revolving Fund (SRF) allocations, the state is currently seeing over $1.5 billion in active water and wastewater improvements.
2. Recent Developments & Projects
The landscape of Louisiana wastewater treatment has shifted dramatically in the last three years, moving from reactive maintenance to proactive resilience planning. Key developments include:
- Consent Decree Compliance: Major municipalities, including Shreveport and Baton Rouge, are nearing the completion of multi-decade, billion-dollar consent decree programs focused on wet-weather capacity and collection system rehabilitation.
- Energy Resilience: Following Hurricane Ida (2021), there is a massive push for onsite power generation and microgrids at treatment plants. The Sewerage and Water Board of New Orleans (SWBNO) is leading this with a dedicated power complex to ensure sewer pumping reliability during grid failures.
- Regionalization: Areas like St. Tammany Parish are moving toward consolidating smaller, inefficient package plants into larger regional facilities to improve effluent quality and reduce operational expenditures (OPEX).
- Nutrient Management: With the Gulf of Mexico hypoxia zone directly downstream, Louisiana plants are facing stricter scrutiny regarding nitrogen and phosphorus limits, driving upgrades in biological nutrient removal (BNR) technologies.
3. Top 20 Largest Treatment Plants in Louisiana
Below is a ranked list of the largest wastewater treatment facilities in Louisiana based on design capacity (MGD). These facilities represent the backbone of the state’s sanitation infrastructure.
| Rank | Plant Name | City/Parish | Design Capacity (MGD) | Population Served | Operating Authority |
|---|---|---|---|---|---|
| 1 | East Bank WWTP | New Orleans | 122.0 | 300,000+ | Sewerage & Water Board of New Orleans |
| 2 | South WWTP | Baton Rouge | 68.0 | 245,000 | East Baton Rouge Sewerage Commission |
| 3 | Lucas WWTP | Shreveport | 64.0 | 160,000 | City of Shreveport |
| 4 | Marrero WWTP | Marrero | 36.2 | 140,000 | Jefferson Parish |
| 5 | East Bank WWTP | Jefferson Parish | 36.0 | 120,000 | Jefferson Parish |
| 6 | North WWTP | Baton Rouge | 28.5 | 110,000 | East Baton Rouge Sewerage Commission |
| 7 | North Regional WWTP | Shreveport | 23.0 | 60,000 | City of Shreveport |
| 8 | Ambassador Caffery WWTP | Lafayette | 18.5 | 85,000 | Lafayette Utilities System |
| 9 | West Bank WWTP | New Orleans | 18.0 | 55,000 | Sewerage & Water Board of New Orleans |
| 10 | Lake Charles Plant A | Lake Charles | 16.0 | 45,000 | City of Lake Charles |
| 11 | Bossier City Red River WWTP | Bossier City | 16.0 | 50,000 | City of Bossier City |
| 12 | Monroe WWTP | Monroe | 16.0 | 47,000 | City of Monroe |
| 13 | Alexandria WWTP | Alexandria | 15.0 | 45,000 | City of Alexandria |
| 14 | Kenner WWTP | Kenner | 13.5 | 66,000 | City of Kenner |
| 15 | Houma Main WWTP | Houma | 12.0 | 33,000 | Terrebonne Parish |
| 16 | Slidell WWTP | Slidell | 10.0 | 28,000 | City of Slidell |
| 17 | Mandeville WWTP | Mandeville | 8.5 | 12,000 | City of Mandeville |
| 18 | Ruston WWTP | Ruston | 8.0 | 22,000 | City of Ruston |
| 19 | Natchitoches WWTP | Natchitoches | 7.5 | 18,000 | City of Natchitoches |
| 20 | Vermilion River WWTP | Lafayette | 6.0 | 25,000 | Lafayette Utilities System |
Top 5 Plant Profiles
1. East Bank WWTP – New Orleans
- Location: New Orleans, Orleans Parish
- Design Capacity: 122 MGD (Peak wet weather flow > 200 MGD)
- Operating Authority: Sewerage & Water Board of New Orleans (SWBNO)
- Receiving Water: Mississippi River
- Treatment Process: High-purity oxygen activated sludge system.
- Infrastructure: Utilizes fluidized bed incineration for biosolids reduction (one of the largest in the region). The facility is heavily integrated with the city’s complex drainage pumping network for power needs.
- Recent Upgrades: Currently undergoing major power reliability upgrades via the new Power Complex project to ensure operation during hurricanes.
- Compliance: Operating under a significant Federal Consent Decree aimed at reducing SSOs and upgrading aging collection infrastructure.
2. South WWTP – Baton Rouge
- Location: Baton Rouge, East Baton Rouge Parish
- Design Capacity: 68 MGD (Peak capacity expanded to 200 MGD for wet weather)
- Operating Authority: East Baton Rouge Sewerage Commission (Managed by Jacobs)
- Receiving Water: Mississippi River
- Treatment Process: Preliminary screening, primary clarification, activated sludge, and UV disinfection.
- Infrastructure: Features a comprehensive supervisory control and data acquisition (SCADA) system linking hundreds of pump stations.
- Recent Upgrades: A massive $1.6 billion “SSO Program” recently expanded peak flow capacity and constructed a wet weather improvement facility to handle subtropical storm surges.
3. Lucas WWTP – Shreveport
- Location: Shreveport, Caddo Parish
- Design Capacity: 64 MGD
- Operating Authority: City of Shreveport
- Receiving Water: Red River
- Treatment Process: Extended aeration activated sludge with biological nutrient removal capabilities.
- Infrastructure: Includes extensive sludge dewatering facilities and anaerobic digesters.
- Recent Upgrades: Part of the “Clean Water Shreveport” consent decree program. Recent projects include headworks rehabilitation and clarifier mechanism replacements.
4. Marrero WWTP – Jefferson Parish
- Location: Marrero, Jefferson Parish (West Bank)
- Design Capacity: 36.2 MGD
- Operating Authority: Jefferson Parish Department of Sewerage
- Receiving Water: Mississippi River
- Treatment Process: Secondary treatment via activated sludge.
- Recent Upgrades: Recent focus on generator reliability and lift station upgrades within the collection system.
5. East Bank WWTP – Jefferson Parish
- Location: Metairie, Jefferson Parish
- Design Capacity: 36.0 MGD
- Operating Authority: Jefferson Parish Department of Sewerage
- Receiving Water: Mississippi River
- Infrastructure: Serves the densely populated Metairie area. Heavy focus on odor control technologies due to proximity to residential zones.
4. Plants with Approved Budgets & Expansion Projects
Louisiana is currently in a high-activity phase for capital improvements, driven by federal consent decrees and new federal funding streams. Below are major projects currently active or funded.
A. Major Projects Under Construction (2024-2026)
SWBNO West Power Complex – New Orleans
- Location: New Orleans, LA
- Project Scope: Construction of a dedicated substation and frequency changers to power both water and wastewater pumps, replacing aging steam turbines. While technically a power project, it is critical for the WWTP’s operation.
- Total Budget: $300+ Million
- Funding: State Capital Outlay, City Bonds, Federal Grants
- Timeline: Construction ongoing; expected commissioning 2025.
- Key Contractors: Industrial electrical specialists and SWBNO internal engineering oversight.
- Expected Benefits: elimination of “boil water” advisories caused by power dips and prevention of sewer backups during storms.
Clean Water Shreveport – Lucas WWTP Peak Flow Improvements
- Location: Shreveport, LA
- Project Scope: Upgrades to aeration basins, final clarifiers, and chlorine contact chambers to handle wet weather flows.
- Total Budget: $40 Million (Part of larger $1B program)
- Funding: SRF Loans, Revenue Bonds
- Timeline: Completion expected late 2025.
- Project Drivers: EPA Consent Decree compliance to eliminate SSOs.
- Technology: High-efficiency aeration blowers and SCADA integration.
Mandeville Wastewater Consolidation
- Location: St. Tammany Parish
- Project Scope: Decommissioning smaller, failing package plants and routing flow to the upgraded Mandeville treatment facility.
- Total Budget: $15 Million
- Funding: Louisiana DEQ SRF Loan
- Timeline: Construction 2024-2026.
- Expected Benefits: Reduction in nutrient loading to Lake Pontchartrain.
B. Projects in Design/Planning Phase (2025-2027)
- Lafayette South Sewer Treatment Plant Expansion:
- Estimated Budget: $65 Million
- Scope: Capacity expansion to support southern parish growth.
- Status: Engineering design and land acquisition.
- Bossier City NE WWTP Expansion:
- Estimated Budget: $25 Million
- Scope: Expansion to accommodate rapid residential growth in northern Bossier.
- Funding: Anticipated SRF and local bonds.
C. Summary Statistics
Louisiana Infrastructure Investment Snapshot
- Total Active Capital Investment: ~$1.8 Billion (2023-2027)
- Primary Project Driver: Consent Decree Compliance (65% of spend)
- Secondary Driver: Hurricane Resilience/Power Reliability
- Major Funding Source: State Revolving Fund (SRF) & WIFIA Loans
- Key Market: Heavy demand for wet-weather treatment technologies and high-capacity pumps.
5. Regulatory & Compliance Landscape
The regulatory environment in Louisiana is enforced by the Louisiana Department of Environmental Quality (LDEQ) under the delegated NPDES program (LPDES). Key regulatory trends include:
- Sanitary Sewer Overflows (SSOs): The EPA Region 6 has been aggressive in issuing consent decrees to Louisiana municipalities (New Orleans, Shreveport, Baton Rouge, Gretna) to address SSOs caused by the state’s heavy rainfall and subsiding soils.
- Nutrient Reduction Strategy: Louisiana is a member of the Hypoxia Task Force. While strict numeric nutrient criteria are not yet universal in permits, major facilities discharging to the Mississippi River are increasingly required to monitor and reduce Nitrogen and Phosphorus to protect the Gulf of Mexico.
- Resilience Standards: Post-Hurricane Ida, there is increased regulatory pressure to ensure facilities have elevated electrical components and redundant backup power capable of running for 7-14 days off-grid.
6. Infrastructure Challenges & Opportunities
Challenges:
- Inflow & Infiltration (I/I): Louisiana’s high water table and aging clay pipes lead to massive I/I. Engineering solutions focusing on trenchless rehabilitation (CIPP) are in high demand.
- Soft Soils: Construction of heavy treatment infrastructure requires extensive piling and foundation work, increasing capital costs.
- Operator Shortage: Like the national trend, rural Louisiana faces a shortage of certified Class IV wastewater operators.
Opportunities:
- Decentralized to Centralized: There is a strong market for engineering firms to design consolidation plans for the hundreds of small, private package plants scattered across parishes.
- Industrial Pretreatment: With a heavy petrochemical presence, there are significant opportunities for industrial wastewater treatment technologies and pretreatment program management.
7. Technology Trends in Louisiana
- SCADA & Automation: Due to the flat topography, Louisiana collection systems rely heavily on lift stations (New Orleans alone has nearly 100). Utility-wide SCADA integration is a top technology trend.
- Peracetic Acid (PAA) Disinfection: Several facilities are exploring PAA as an alternative to chlorination to reduce disinfection byproducts (DBPs).
- Submersible Pumping: Shift toward submersible pumps that can operate even if dry wells flood during hurricanes.
8. Directory of Facilities
For a complete list of facilities, browse our searchable database. (Links below serve as placeholders for site architecture)
- New Orleans Region Treatment Plants
- Baton Rouge Metro Treatment Plants
- Shreveport & North Louisiana Facilities
- Lafayette & Acadiana Region Plants
9. Resources for Engineers & Operators
- Louisiana Department of Environmental Quality (LDEQ): Water Permits Division
- Louisiana Water Environment Association (LWEA): The state chapter of WEF, offering training and annual conferences.
- Louisiana Rural Water Association (LRWA): Key resource for smaller parish systems and operator certification.
- State Revolving Fund (SRF): Information on low-interest loans for infrastructure projects.
10. FAQ
What is the largest wastewater treatment plant in Louisiana?
The East Bank Wastewater Treatment Plant in New Orleans is the largest, with a design capacity of 122 MGD and the ability to handle peak flows significantly higher during storm events.
Which Louisiana cities are under EPA Consent Decrees for wastewater?
New Orleans, Baton Rouge, and Shreveport are all currently operating under significant federal consent decrees requiring billions in infrastructure upgrades to prevent sanitary sewer overflows.
What funding is available for wastewater projects in Louisiana?
Funding is primarily available through the Clean Water State Revolving Fund (CWSRF) administered by LDEQ, Federal WIFIA loans, and recent allocations from the IIJA (Bipartisan Infrastructure Law).
How many wastewater treatment plants are in Louisiana?
While there are hundreds of small permits, there are approximately 250 municipal-grade mechanical treatment facilities serving towns and cities across the state.
What is the primary treatment challenge in Louisiana?
Inflow and Infiltration (I/I) is the primary challenge due to the high water table, heavy rainfall, and soil subsidence, which damages underground pipes and overwhelms treatment plants with dilute water.