East Jefferson Wastewater Treatment Plant

1. INTRODUCTION

The East Jefferson Wastewater Treatment Plant (EJEFF) serves as the primary sanitary infrastructure backbone for the East Bank of Jefferson Parish, Louisiana. Situated in Metairie, a major suburb of New Orleans, this facility treats wastewater for approximately 250,000 residents and a dense commercial corridor. Operated by the Jefferson Parish Department of Sewerage, the plant is designed with an average flow capacity of 62.4 MGD, making it one of the largest treatment facilities in the state of Louisiana.

Operating in a region characterized by high water tables, significant rainfall, and hurricane threats, the EJEFF is a critical asset for public health and environmental protection. The facility discharges treated effluent into the Mississippi River, requiring strict adherence to Louisiana Department of Environmental Quality (LDEQ) standards. Following significant weather events like Hurricane Katrina and Hurricane Ida, the plant has become a focal point for resilience engineering, featuring robust backup power generation and flood mitigation infrastructure.

2. FACILITY OVERVIEW

A. Service Area & Coverage

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The facility services the entire “East Bank” of Jefferson Parish. This area is geographically bounded by Lake Pontchartrain to the north, the Mississippi River to the south, the Orleans Parish line to the east, and St. Charles Parish to the west. The service area is highly urbanized, consisting of dense residential subdivisions, the Elmwood industrial park, and the commercial corridors of Veterans Memorial Boulevard. The collection system feeding the plant is extensive, relying on a complex network of gravity lines and lift stations to overcome the flat topography of the Mississippi River Delta.

B. Operational Capacity

The plant operates with a design average flow of approximately 62.4 MGD. However, due to the age of the collection system and local geology, the facility experiences significant Inflow and Infiltration (I/I) during storm events. The plant is engineered to handle peak hydraulic flows significantly higher than its average daily design to prevent sanitary sewer overflows (SSOs). Historical trends indicate average daily dry weather flows hovering between 35-45 MGD, providing ample capacity for dry-weather growth, though wet-weather peaking remains a primary operational focus.

C. Discharge & Compliance

Treated effluent is discharged into the Mississippi River via a submerged outfall. Given the immense volume and dilution capacity of the Mississippi River, the plant’s discharge permit (NPDES LA0037885) focuses heavily on Total Suspended Solids (TSS), Biochemical Oxygen Demand (BOD), and Fecal Coliform to protect downstream water usage. The plant consistently operates within compliance parameters, utilizing conventional secondary treatment to meet requirements.

3. TREATMENT PROCESS

The East Jefferson Wastewater Treatment Plant utilizes a conventional activated sludge process designed to reduce organic loads and solids prior to river discharge.

A. PRELIMINARY TREATMENT

Raw influent enters the headworks facility where it undergoes physical screening.

• Screening: Mechanically cleaned bar screens remove large debris, rags, and plastics to protect downstream pumps and process equipment. Screenings are washed, compacted, and disposed of at a sanitary landfill.
• Grit Removal: Aerated grit chambers are utilized to reduce the velocity of the wastewater, allowing heavy inorganic materials (sand, gravel, coffee grounds) to settle while keeping organic material in suspension. This is particularly critical in Jefferson Parish due to the sandy soil composition surrounding the collection pipes.

B. PRIMARY TREATMENT

Following headworks, flow is directed to primary clarifiers. These large settling tanks reduce the velocity of the wastewater to allow settleable solids to drop to the bottom as raw sludge, while fats, oils, and grease (FOG) float to the surface for skimming. The primary treatment stage typically removes 50-60% of suspended solids and 30-40% of BOD, significantly reducing the load on the biological stage.

C. SECONDARY TREATMENT

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The core biological treatment occurs in the aeration basins using an Activated Sludge process.

• Aeration Basins: The wastewater is mixed with Return Activated Sludge (RAS) to form mixed liquor. Air is introduced into the basins (historically via mechanical surface aerators or coarse bubble diffusers) to provide oxygen for microorganisms to consume dissolved organic matter.
• Secondary Clarifiers: The mixed liquor flows to secondary clarifiers where the biological floc settles out. A portion of this settled biomass is returned to the head of the aeration basins (RAS), while the excess growth is removed as Waste Activated Sludge (WAS).

D. DISINFECTION

The clarified effluent undergoes disinfection to eliminate pathogenic organisms.

• Chlorination: The plant utilizes chlorine gas or sodium hypochlorite for disinfection in contact chambers.
• Discharge: Following sufficient contact time to meet fecal coliform limits, the treated water is discharged to the Mississippi River. Dechlorination is generally required to ensure residual chlorine does not harm aquatic life in the mixing zone.

E. SOLIDS HANDLING

Solids processing is a major operational component at EJEFF.

• Thickening: Primary sludge and WAS are thickened (often via gravity thickeners or dissolved air flotation) to increase solids concentration.
• Anaerobic Digestion: Thickened sludge is stabilized in anaerobic digesters. This process breaks down volatile solids, reduces pathogen counts, and generates biogas (methane).
• Dewatering: Digested sludge is dewatered using belt filter presses to create a cake suitable for transport.
• Disposal: The dewatered biosolids are transported to the nearby Jefferson Parish Sanitary Landfill or River Birch Landfill for disposal.

4. INFRASTRUCTURE & FACILITIES

A. Physical Plant

The site covers a substantial footprint in a highly developed zone of Metairie. It houses administration buildings, a fully equipped SCADA control center, and an on-site laboratory capable of performing compliance testing for BOD, TSS, pH, and Chlorine Residual.

B. Energy Resilience

Following the catastrophic impacts of Hurricane Katrina (2005) and Hurricane Ida (2021), energy independence is a primary infrastructure feature. The plant is equipped with massive emergency backup generators capable of running the entire facility during grid outages. These systems are tested weekly and are critical for preventing back-ups during tropical cyclones when the power grid frequently fails.

C. Odor Control

Due to its location near residential neighborhoods and the high-traffic Transcontinental Drive, odor control is a sensitive operational parameter. The facility utilizes chemical scrubbers and covers on key process units (such as the headworks and sludge holding tanks) to mitigate nuisance odors.

5. RECENT UPGRADES & MAJOR PROJECTS

Jefferson Parish has invested heavily in the Capital Improvement Plan (CIP) for the sewerage department to address aging infrastructure and resiliency.

Emergency Power & Resiliency Improvements (2021-2023)

• Scope: Installation and rehabilitation of emergency generators and electrical switchgear.
• Driver: Hurricane Ida exposed vulnerabilities in the regional power grid; ensuring continuous operation during storms prevents sewer backups into homes.
• Significance: This project ensures the plant maintains 100% operational capacity during Entergy grid failures.

Headworks Rehabilitation (Ongoing/Recent)

• Scope: Replacement of aging mechanical bar screens and grit removal mechanisms.
• Driver: Aging equipment and high grit loads from I/I.
• Benefit: Improved capture of non-biological debris, protecting the aeration basins and sludge pumps from abrasion and clogging.

SCADA System Modernization

• Scope: Migration from legacy controls to a modern SCADA network.
• Benefit: Provides operators with real-time data visualization, automated alarm systems, and remote monitoring capabilities, essential for managing flows during rapid rain events.

6. REGULATORY COMPLIANCE

A. Permit Requirements

The facility operates under LPDES Permit No. LA0037885.

• BOD5: Monthly Average typically 30 mg/L.
• TSS: Monthly Average typically 30 mg/L.
• Fecal Coliform: Strict limits for river discharge.
• pH: 6.0 – 9.0 Standard Units.

B. Compliance History

The East Jefferson WWTP generally maintains a strong compliance record regarding effluent quality. Challenges are primarily hydraulic in nature—specifically related to high wet-weather flows that stress the secondary clarifiers. The Parish works closely with LDEQ to manage these wet-weather events and minimize sanitary sewer overflows (SSOs) in the collection system.

8. CHALLENGES & FUTURE PLANNING

A. Inflow and Infiltration (I/I)

The predominant challenge for the East Jefferson system is I/I. The collection system consists of aging clay and concrete pipes in shifting, subsiding deltaic soils. During heavy rains, groundwater and stormwater enter the sanitary system, causing flows at the plant to spike from 40 MGD to over 100 MGD in hours. Future planning focuses heavily on collection system rehabilitation (CIPP lining) rather than just plant expansion.

B. Climate Resilience

Located in a hurricane zone, the plant must withstand high winds and potential storm surges. Future planning involves hardening electrical substations and raising critical control equipment above potential flood stages.

10. TECHNICAL SPECIFICATIONS SUMMARY

11. RELATED FACILITIES

The East Jefferson system is supported by a vast network of lift stations. While EJEFF handles the East Bank, the West Jefferson Wastewater Treatment Plant in Marrero serves the population on the West Bank of the river. The two systems are hydraulically distinct due to the Mississippi River dividing the parish.

12. FAQ SECTION

Technical Questions

1. What is the average daily flow at the East Jefferson WWTP?
The plant typically sees dry weather flows in the range of 35-45 MGD, though the design capacity is 62.4 MGD.

2. Does the plant utilize nutrient removal?
Currently, the facility is designed for secondary treatment (BOD/TSS removal). Strict Nitrogen or Phosphorus limits are not typically mandated for lower Mississippi River discharges due to the river’s high volume, though monitoring is standard.

3. How are biosolids disposed of?
After anaerobic digestion and dewatering via belt presses, the biosolids cake is transported to local sanitary landfills.

Public Interest Questions

4. Does the plant smell?
Like all wastewater facilities, odors can occur. However, Jefferson Parish employs odor control scrubbers at the headworks and sludge handling areas to minimize impact on the surrounding Metairie community.

5. Is the plant safe during hurricanes?
Yes. The facility is equipped with extensive backup power generation to maintain operations when the municipal power grid fails, preventing sewage backups during storms.