Jefferson Parish East Bank Wastewater Treatment Plant

1. INTRODUCTION

The Jefferson Parish East Bank Wastewater Treatment Plant (EBWWTP) serves as the primary sanitary infrastructure asset for the populous East Bank of Jefferson Parish, located immediately adjacent to New Orleans. Operated by the Jefferson Parish Department of Sewerage, this facility is critical to the environmental health of the Mississippi River basin. With a design average flow of 36 million gallons per day (MGD) and the hydraulic capability to process peak wet weather flows exceeding 80 MGD, it is one of the largest wastewater treatment facilities in the state of Louisiana.

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Distinguished by its use of High Purity Oxygen (HPO) activated sludge technology—a legacy of the “UNOX” systems popular during its major expansion phase—the plant is currently the focal point of a comprehensive Capital Improvement Program driven by federal consent decrees. Following significant infrastructure stress during Hurricane Katrina (2005) and Hurricane Ida (2021), the facility has become a case study in resilience engineering, currently undergoing multi-million dollar upgrades to enhance headworks performance, solids handling, and emergency power generation.

2. FACILITY OVERVIEW

A. Service Area & Coverage

The EBWWTP services the “East Bank” of Jefferson Parish, a dense suburban corridor squeezed between Lake Pontchartrain to the north and the Mississippi River to the south. The service area encompasses the unincorporated metropolis of Metairie, the City of Kenner, the City of Harahan, and River Ridge. The collection system is massive, consisting of over 850 miles of gravity mains and force mains, supported by more than 250 distinct lift stations that combat the region’s flat topography and high water table.

B. Operational Capacity

While the plant is permitted for a design flow of 36 MGD, the facility operates in a region prone to significant inflow and infiltration (I&I). Consequently, while dry weather flows average between 25 and 30 MGD, wet weather events can trigger instantaneous peaks exceeding 80 MGD. The plant’s hydraulics are designed to handle these surges, utilizing equalization capacities and aggressive pumping strategies to prevent sanitary sewer overflows (SSOs) upstream.

C. Discharge & Compliance

Treated effluent is discharged into the Mississippi River via a submerged outfall. The facility operates under LPDES Permit No. LA0037567, administered by the Louisiana Department of Environmental Quality (LDEQ) under authority from the EPA. Compliance is strictly monitored for Biochemical Oxygen Demand (BOD5), Total Suspended Solids (TSS), Fecal Coliform, and pH. The facility is currently operating under provisions of a Federal Consent Decree aimed at reducing SSOs and updating aging infrastructure.

3. TREATMENT PROCESS

The East Bank WWTP utilizes a High Purity Oxygen (HPO) activated sludge process, a variation of secondary treatment that allows for higher organic loading rates and smaller footprint aeration basins compared to conventional air systems.

A. Preliminary Treatment

Raw wastewater enters the facility through large diameter force mains. The headworks facility, recently the subject of extensive rehabilitation, utilizes mechanical bar screens to remove large debris, rags, and plastics. Following screening, flow enters aerated grit chambers designed to settle out inorganic solids (sand, gravel, coffee grounds) which are then classified and hauled to a landfill. This stage is critical for protecting downstream pumps and sludge processing equipment from abrasion.

B. Primary Treatment

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Flow proceeds to rectangular primary clarifiers. Here, gravity separation settles out approximately 60-70% of suspended solids and 30-40% of BOD. Floating grease and oils are skimmed from the surface. The primary sludge is pumped to the solids handling complex, while the primary effluent flows to the secondary treatment stage.

C. Secondary Treatment (High Purity Oxygen)

The core of the EBWWTP is the HPO activated sludge system. Unlike conventional aeration which blows atmospheric air (21% oxygen) into the water, this system utilizes covered, multi-stage aeration basins injected with >90% pure oxygen. The oxygen is generated on-site (historically via Cryogenic Air Separation or Pressure Swing Adsorption). This high partial pressure of oxygen accelerates biological metabolism, allowing the plant to treat high-strength waste effectively within a reduced hydraulic retention time. The mixed liquor then flows to secondary clarifiers where the biological floc settles, producing a clear effluent.

D. Disinfection

The clarified secondary effluent undergoes disinfection using sodium hypochlorite (liquid chlorine). To protect aquatic life in the Mississippi River, the chlorinated water is then dechlorinated using sodium bisulfite or sulfur dioxide prior to final discharge. The contact chambers ensure sufficient dwell time to meet fecal coliform limits before the water enters the outfall.

F. Solids Handling

Solids handling at EBWWTP has historically involved thickening followed by fluid bed incineration. Primary and Waste Activated Sludge (WAS) are thickened (typically via gravity thickeners for primary and dissolved air flotation or gravity belt thickeners for WAS). The thickened sludge is dewatered using belt filter presses. While the facility houses a Fluid Bed Incinerator for thermal reduction of biosolids, operational challenges have frequently necessitated the hauling of dewatered sludgecake to landfills, such as the Jefferson Parish Sanitary Landfill.

4. INFRASTRUCTURE & FACILITIES

A. Physical Plant

The site occupies a significant industrial footprint in River Ridge, bordered by rail lines and the Mississippi River levee. The site includes the Administration Building, maintenance shops, the Oxygen Generation Facility (a distinct industrial structure housing compressors and cold boxes), and the massive concrete covered aeration decks typical of HPO plants.

B. Energy Systems

The East Bank plant is a major energy consumer, primarily due to the main sewage pumps and the oxygen generation compressors. Following the devastation of Hurricane Ida in 2021, which left the region without grid power for days, Jefferson Parish has prioritized energy resilience. The facility is equipped with large-scale emergency diesel generators capable of running critical process trains during grid failures to prevent backups in the collection system.

C. Odor Control

Located near residential neighborhoods in River Ridge, odor control is a sensitive operational parameter. The headworks and primary clarifier weirs are primary odor sources. The plant utilizes chemical scrubbers (typically caustic/bleach or biological scrubbers) to treat foul air extracted from these process areas before venting to the atmosphere.

5. RECENT UPGRADES & MAJOR PROJECTS

Jefferson Parish is currently executing a multi-year Sewer Capital Improvement Program (SCIP) aimed at satisfying the requirements of their Federal Consent Decree.

Major Upgrade: Headworks and Grit Removal Rehabilitation (2018-2023)

• Project Scope: Replacement of aging mechanical bar screens, rehabilitation of grit chambers, and installation of new grit pumps and classifiers.
• Estimated Cost: ~$15 – $20 Million
• Drivers: Equipment obsolescence and the need to protect downstream HPO basins from grit accumulation.
• Results: Improved screening capture rates and reduced wear on sludge processing equipment.

Emergency Power & Electrical Distribution (Post-Ida Initiatives)

• Project Scope: Hardening of the electrical substation serving the plant and installation/upgrading of auxiliary power systems.
• Funding: Combination of FEMA Hazard Mitigation Grants and local funds.
• Technical Highlights: Elevation of critical switchgear above flood stages and integration of redundant power feeds.

Current/Upcoming Projects (2024-2027)

Future planning includes the potential rehabilitation or full replacement of the fluid bed incinerator system to regain thermal processing capabilities, reducing reliance on landfilling. Additionally, there are ongoing projects to rehabilitate the concrete structures of the secondary clarifiers and covered aeration basins, which suffer from long-term corrosion associated with HPO headspace gases.

6. REGULATORY COMPLIANCE & ENVIRONMENTAL PERFORMANCE

A. Permit Requirements

The EBWWTP operates under a Louisiana Pollutant Discharge Elimination System (LPDES) permit. Standard secondary treatment limits apply:

• BOD5: 30 mg/L (Monthly Average)
• TSS: 30 mg/L (Monthly Average)
• pH: 6.0 – 9.0 Standard Units
• Fecal Coliform: Strictly limited during recreation months (May-Oct)

B. Compliance History & Consent Decree

Like many municipalities in the Gulf South with aging infrastructure and high water tables, Jefferson Parish entered into a Consent Decree with the EPA and DOJ. The primary focus is not just the plant performance, which generally meets permit limits, but the reduction of Sanitary Sewer Overflows (SSOs) in the collection system. The EBWWTP must maintain high availability to accept peak flows to prevent backups in the streets of Metairie and Kenner.

7. OPERATIONAL EXCELLENCE

The facility is staffed 24/7 by a team of licensed wastewater operators, maintenance mechanics, electricians, and laboratory technicians. Jefferson Parish requires operators to hold Louisiana Department of Health (LDH) certifications in Wastewater Treatment. The on-site laboratory performs daily process control testing, while compliance samples are often analyzed by certified third-party laboratories to ensure data integrity.

8. CHALLENGES & FUTURE PLANNING

A. Current Challenges

Inflow and Infiltration (I&I): The flat topography and aging clay pipes in the collection system allow significant groundwater and stormwater intrusion, hydraulically overloading the plant during tropical storms.

Solids Disposal: With landfill costs rising and the incinerator often offline, managing the sheer volume of biosolids produced by 300,000 people is a logistical and financial challenge.

B. Future Planning

The Parish is moving toward a more automated SCADA (Supervisory Control and Data Acquisition) environment to improve real-time decision-making. Long-term planning involves assessing the structural viability of the 1980s-era expansion structures and preparing the facility for stricter future nutrient limits (Nitrogen/Phosphorus) that may be imposed on Mississippi River dischargers to combat the Gulf of Mexico Hypoxia Zone.

10. TECHNICAL SPECIFICATIONS SUMMARY

12. FAQ SECTION

Technical Questions

Q: Does the East Bank WWTP perform nutrient removal?
A: Currently, the facility is designed for carbonaceous removal (BOD/TSS). It does not have specific tertiary processes for biological nitrogen or phosphorus removal, although some incidental removal occurs during secondary treatment.

Q: What is the primary operational advantage of the HPO system used here?
A: The High Purity Oxygen system allows the plant to maintain a high mixed liquor suspended solids (MLSS) concentration, enabling it to treat high waste loads in a smaller physical footprint than conventional air activated sludge plants.

Q: Is the facility under a Consent Decree?
A: Yes, Jefferson Parish is operating under a Federal Consent Decree focused on upgrading collection systems and treatment facilities to eliminate sanitary sewer overflows.

Public Interest Questions

Q: What causes odors near the plant?
A: Odors usually originate from the “headworks” where raw sewage first enters the plant. The Parish utilizes chemical scrubbers to neutralize these odors, though extreme weather or maintenance events can sometimes lead to transient odors.

Q: How does the plant handle hurricanes?
A: The plant is considered critical infrastructure. It is equipped with flood protection and massive emergency generators to ensure pumps continue running even if the city loses power, preventing sewage from backing up into homes.