Baton Rouge Wastewater Treatment Plant

FACILITY BASIC INFORMATION

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1. INTRODUCTION

The South Wastewater Treatment Plant (SWWTP) serves as the cornerstone of wastewater infrastructure for East Baton Rouge Parish, Louisiana. As the largest facility within the City-Parish system, the SWWTP is engineered to handle massive hydraulic loads driven by the region’s subtropical climate and heavy rainfall. Operated by the Department of Environmental Services, this facility is critical to protecting the water quality of the Mississippi River, one of the world’s most vital commercial waterways.

Currently treating an average of 65 million gallons per day (MGD) with a wet-weather peak capacity of 200 MGD, the plant has recently been the focal point of the comprehensive $1.6 billion Baton Rouge Sanitary Sewer Overflow (SSO) Control Program. Through a series of strategic capital improvements, including advanced solids handling and ultraviolet disinfection upgrades, the SWWTP has evolved from a conventional facility into a modern, regulatory-compliant asset designed to meet the environmental challenges of the 21st century.

2. FACILITY OVERVIEW

A. Service Area & Coverage

The SWWTP services the southern basin of East Baton Rouge Parish, a dense urban and suburban region encompassing the majority of the city’s residential population and significant commercial corridors. The collection system is characterized by a flat topography, necessitating a complex network of over 500 pump stations throughout the parish to convey flow to the treatment facilities. The service area includes the Louisiana State University (LSU) campus and major industrial zones bordering the Mississippi River.

B. Operational Capacity

The facility is designed with significant peaking factors to accommodate Inflow and Infiltration (I/I) common in the Gulf Coast region.

• Design Average Flow: 102 MGD
• Peak Hydraulic Capacity: 200 MGD
• Historical Trends: While dry weather flows average between 50-65 MGD, extreme weather events frequently test the hydraulic limits of the headworks, necessitating the recent “Wet Weather Improvements” aimed at ensuring process stability during storm surges.

C. Discharge & Compliance

Treated effluent is discharged directly into the Mississippi River. Due to the river’s massive dilution capacity, nutrient limits (Nitrogen/Phosphorus) have historically been less stringent than in sensitive bay estuaries; however, the facility operates under strict limits for BOD, TSS, and Fecal Coliform/E. coli. The plant operates under Louisiana Pollutant Discharge Elimination System (LPDES) permit LA0036137, administered by the Louisiana Department of Environmental Quality (LDEQ).

3. TREATMENT PROCESS

The SWWTP utilizes a conventional activated sludge process modified for high-efficiency solids capture and disinfection. The treatment train is designed for robustness, capable of absorbing shock loads common in industrial-heavy municipalities.

A. PRELIMINARY TREATMENT

Raw wastewater enters the facility through the master pump station force mains. The headworks facility was significantly upgraded to improve screenings and grit removal reliability.

• Screening: Mechanically cleaned coarse and fine bar screens remove rags, plastics, and debris to protect downstream pumps.
• Grit Removal: Vortex grit chambers utilize centrifugal force to separate sand, gravel, and heavy inorganic materials, which are washed and dewatered before landfill disposal.
• Flow Equalization: During peak wet weather events, excess flow management protocols are enacted to prevent hydraulic washout of the biological mass.

B. PRIMARY TREATMENT

Flow proceeds to primary clarification basins where gravity settling occurs.

• Clarifiers: Multiple large-diameter circular primary clarifiers reduce the organic load on the secondary system.
• Efficiency: Typically achieves 30-35% removal of BOD and 50-60% removal of Total Suspended Solids (TSS).
• Primary Sludge: Settled solids are pumped directly to the gravity thickeners for processing.

C. SECONDARY TREATMENT

The biological heart of the plant utilizes Conventional Activated Sludge.

• Aeration Basins: The plant operates rectangular aeration basins equipped with surface mechanical aerators and diffused air systems to maintain dissolved oxygen levels. The microorganisms consume dissolved organic matter (BOD) and convert ammonia to nitrate (nitrification) depending on seasonal operational modes.
• Secondary Clarifiers: Mixed liquor flows to secondary clarifiers where biological floc settles. The clear supernatant overflows the weirs to disinfection.
• RAS/WAS: Return Activated Sludge (RAS) is recycled to the head of the aeration basins, while Waste Activated Sludge (WAS) is diverted to solids handling.

D. DISINFECTION

In a major deviation from historical gas chlorination, the SWWTP recently transitioned to Ultraviolet (UV) Disinfection.

• Technology: High-intensity UV banks disrupt the DNA of pathogens (bacteria, viruses, protozoa), preventing reproduction.
• Safety & Environment: This transition eliminated the storage of hazardous chlorine gas on-site and removed the potential for chlorinated byproducts (trihalomethanes) entering the Mississippi River.

E. SOLIDS HANDLING

Baton Rouge operates one of the most advanced solids handling facilities in the region, utilizing incineration to minimize disposal volume.

• Thickening: Gravity thickeners reduce water content of primary sludge and WAS.
• Dewatering: Belt filter presses squeeze remaining water from the thickened sludge, producing a “cake.”
• Incineration: The facility replaced aging Multiple Hearth Incinerators (MHI) with modern Fluidized Bed Incinerators (FBI). These units offer superior thermal efficiency and lower emissions. The inert ash remaining is landfilled.

4. INFRASTRUCTURE & FACILITIES

A. Physical Plant

The site spans extensive acreage on Gardere Lane, housing not only the treatment train but also administrative offices, a SCADA control center, and fleet maintenance facilities for the Department of Environmental Services. The layout is optimized for loop-access for chemical delivery and sludge hauling trucks.

B. Energy Systems

As a major energy consumer, the SWWTP focuses on efficiency. The conversion to Fluidized Bed Incinerators significantly reduced natural gas consumption compared to the legacy hearth systems. The plant relies on grid power but maintains extensive standby diesel generation capacity to ensure continuous operation during hurricane events, critical for preventing backups during tropical storms.

C. Odor Control

Given the plant’s proximity to developing residential areas, odor control is a priority. The recent headworks and solids handling upgrades included the installation of biotrickling filters and chemical scrubbers to treat foul air extracted from the screening and dewatering buildings, neutralizing hydrogen sulfide (H2S) before release.

5. RECENT UPGRADES & MAJOR PROJECTS

The City-Parish has engaged in a massive overhaul of its wastewater infrastructure under the “Baton Rouge SSO Program.”

South Wastewater Treatment Plant Wet Weather Improvements

• Scope: Upgrades to headworks screening, grit removal, and hydraulic conveyance to handle 200 MGD peak flows reliably.
• Outcome: Eliminated bottlenecks that previously caused upstream backups during heavy rains.

Solids Handling & Incineration Upgrade

• Investment: ~$40 Million
• Technology: Replacement of outdated Multiple Hearth Incinerators with Fluidized Bed Incineration technology.
• Benefits: The new system meets strict MACT (Maximum Achievable Control Technology) air emission standards, reduces fuel usage, and produces a more stable ash product.

Disinfection System Conversion

• Scope: Demolition of chlorine contact tanks and installation of UV disinfection channels.
• Driver: Safety concerns regarding chlorine gas transport and storage, and environmental stewardship.
• Status: Commissioned and operational.

6. REGULATORY COMPLIANCE & ENVIRONMENTAL PERFORMANCE

A. Permit Requirements

The SWWTP operates under LPDES Permit LA0036137. Key discharge parameters include:

• BOD5: Monthly average limits typically set at 30 mg/L (secondary treatment standard).
• TSS: Monthly average limit of 30 mg/L.
• pH: Maintained between 6.0 and 9.0 s.u.
• Fecal Coliform: Strict limits during recreation season (May-Oct) to protect river contact usage.

B. Consent Decree Status

In 2002, the City-Parish entered into a Consent Decree with the EPA and DOJ to address chronic SSOs caused by aging pipes and capacity issues. The SWWTP upgrades were a mandatory component of this agreement. The City-Parish has successfully completed the remedial measures required for the treatment plants and is in the final phases of collection system rehabilitation.

7. OPERATIONAL EXCELLENCE

A. Staffing & Certification

The plant is staffed 24/7/365 by the Department of Environmental Services. Operators are required to hold Louisiana Department of Health (LDH) wastewater certifications, ranging from Class I to Class IV (highest level). The facility emphasizes cross-training between operations and maintenance (O&M) teams.

B. SCADA & Automation

A centralized Supervisory Control and Data Acquisition (SCADA) system provides real-time monitoring of all unit processes. This allows operators to adjust return sludge rates, aeration intensity, and chemical dosing remotely. The system also tracks pump station levels across the southern parish, giving the plant advance warning of incoming flow spikes.

8. CHALLENGES & FUTURE PLANNING

A. Climate Resilience

Located in a hurricane zone, the SWWTP faces threats from storm surge and extreme precipitation. Future planning focuses on hardening electrical infrastructure and raising critical equipment above projected flood elevations. The facility’s emergency response plan is rigorously tested to ensure continuity during tropical events.

B. Inflow & Infiltration (I/I)

Despite the massive investment in the SSO program, I/I remains a challenge due to the high water table in Baton Rouge. Continuous lining of gravity mains and rehabilitation of manholes is an ongoing operational expenditure required to keep clear water out of the sanitary system.

C. Evolving Regulations

While the Mississippi River currently has high assimilation capacity, potential future nutrient criteria (Nitrogen/Phosphorus) for the Gulf of Mexico Hypoxia Zone could necessitate significant biological process retrofits (BNR) in the coming decades.

9. COMMUNITY & REGIONAL IMPACT

The SWWTP enables the economic growth of Baton Rouge by providing reliable utility service to the petrochemical and industrial sectors that anchor the local economy. Furthermore, by upgrading to UV disinfection and improved solids handling, the facility has reduced its environmental footprint, improving air quality for local residents and water quality for downstream users of the Mississippi River.

10. TECHNICAL SPECIFICATIONS SUMMARY

11. RELATED FACILITIES

The SWWTP is part of a broader network managed by the City-Parish. Key related infrastructure includes:

• North Wastewater Treatment Plant (NWWTP): Located near the airport, serving the northern basin of the parish. Also recently upgraded under the SSO program.
• Central Wastewater Treatment Plant: A smaller facility serving the central region.
• Collection System: A vast network comprising over 500 sewer pump stations and thousands of miles of gravity and force mains.

12. FREQUENTLY ASKED QUESTIONS

Technical Questions

1. What is the peak capacity of the Baton Rouge South WWTP?
The facility is designed to handle a peak hydraulic flow of approximately 200 MGD during wet weather events.

2. Does the plant use chlorine for disinfection?
No. The facility has transitioned to Ultraviolet (UV) disinfection, eliminating the use of chlorine gas for effluent treatment.

3. How are solids disposed of at the facility?
Solids are thickened, dewatered using belt presses, and thermally reduced in Fluidized Bed Incinerators. The remaining ash is disposed of in a sanitary landfill.

4. Is the plant under a Consent Decree?
Yes, the City-Parish has been operating under a Consent Decree since 2002 to address Sanitary Sewer Overflows. The majority of the required plant upgrades have been completed.

Public Interest Questions

5. Where does the treated water go?
The treated effluent is discharged via an outfall into the Mississippi River.

6. Who operates the plant?
The plant is operated by the City of Baton Rouge / Parish of East Baton Rouge Department of Environmental Services.

7. How does the plant control odors?
The facility utilizes chemical scrubbers and biotrickling filters, particularly at the headworks and solids handling buildings, to treat odorous air before it is released.