Joint Water Pollution Control Plant Los Angeles County

FACILITY BASIC INFORMATION

• Plant Name: Joint Water Pollution Control Plant (JWPCP)
• Location: Carson, Los Angeles County, California
• Operating Authority: Los Angeles County Sanitation Districts (LACSD)
• Design Capacity: 400 MGD (Million Gallons per Day)
• Current Average Flow: ~260 MGD
• Population Served: ~5.5 million residents
• Service Area: 73 cities and unincorporated areas in Los Angeles County
• Receiving Water Body: Pacific Ocean (Palos Verdes Shelf)
• NPDES Permit Number: CA0053813
• Year Commissioned: 1928 (Modernized continuously)

1. INTRODUCTION

The Joint Water Pollution Control Plant (JWPCP) is one of the largest wastewater treatment facilities in the world and the backbone of the Los Angeles County Sanitation Districts’ (LACSD) Joint Outfall System. Located on a 420-acre site in Carson, California, this facility provides critical sanitation services for over 5.5 million people and thousands of industrial users. While the plant was originally commissioned in 1928, it has evolved into a model of modern engineering, boasting a design capacity of 400 million gallons per day (MGD) and utilizing High Purity Oxygen (HPO) activated sludge processes.

Uniquely, the JWPCP is not just a treatment plant but a resource recovery facility. It is virtually energy self-sufficient, generating electricity from biogenic methane produced during the digestion process. Currently, the facility acts as the hub for the “Clearwater Project”—a massive tunnel infrastructure upgrade—and the “Regional Recycled Water Program,” which aims to transform the plant from a disposal facility into one of the largest sources of purified water in the nation.

Read more4D-Printed Smart Materials For Water Treatment

2. FACILITY OVERVIEW

A. Service Area & Coverage

The JWPCP serves the Joint Outfall System (JOS), a regional network covering approximately 650 square miles. The service area encompasses 73 cities, including Long Beach, Torrance, and Compton, as well as unincorporated areas of Los Angeles County. The collection system feeding the plant includes over 1,400 miles of main trunk sewers and 48 active pumping plants. The demographics served are highly diverse, featuring dense residential zones and one of the largest concentrations of industrial and commercial dischargers in the state.

B. Operational Capacity

While designed for a hydraulic capacity of 400 MGD, the plant currently processes an average daily flow of approximately 260 MGD. This reduction from historical highs of over 300 MGD is largely attributed to successful water conservation efforts across the county. The facility handles peak wet weather flows significantly higher than average, utilizing extensive hydraulic storage and redundant pumping systems. Future capacity planning is now driven less by hydraulic volume and more by the need for advanced nutrient removal and water recycling capabilities.

C. Discharge & Compliance

Treated secondary effluent travels roughly six miles through a network of tunnels to the White Point Outfall Manifold facility in San Pedro. From there, it is discharged into the Pacific Ocean via ocean outfalls extending up to two miles offshore at depths of 200 feet. The discharge is regulated under NPDES Permit CA0053813, issued by the Los Angeles Regional Water Quality Control Board. The facility maintains an exemplary compliance record following the historic shift to full secondary treatment compliance in 2002.

3. TREATMENT PROCESS

The JWPCP utilizes a pure oxygen activated sludge process, selected for its ability to treat high-strength wastewater within a compact footprint. The treatment train is summarized below:

A. PRELIMINARY TREATMENT

Raw wastewater enters the headworks where it passes through mechanical bar screens to remove large debris, rags, and plastics. Following screening, the flow enters aerated grit chambers where heavier inorganic materials (sand, gravel, coffee grounds) settle out. The grit is washed, dewatered, and transported off-site for landfill disposal. Odor control at the headworks is aggressive, utilizing chemical scrubbers to manage sulfides typical of the long retention times in the LA collection system.

B. PRIMARY TREATMENT

Read moreA Day in the Life of a Wastewater Treatment Plant Manager

Flow is distributed to 52 rectangular primary sedimentation tanks. These tanks reduce flow velocity, allowing settleable solids to drop to the bottom as sludge and oils/grease to float to the surface as skimmings.

• Efficiency: The primary stage removes approximately 70% of Total Suspended Solids (TSS) and 35-40% of Biochemical Oxygen Demand (BOD).
• Enhancement: Anionic polymers are occasionally added to enhance settling during peak flows or upset conditions.

C. SECONDARY TREATMENT (High Purity Oxygen)

The JWPCP employs a High Purity Oxygen (HPO) activated sludge process. Unlike conventional aeration which uses ambient air (21% oxygen), HPO systems use >90% pure oxygen generated on-site via a Cryogenic Air Separation plant.

• Reactors: The biological reactors are covered (gastight) to contain the high-oxygen atmosphere and control odors. This allows for higher mixed liquor suspended solids (MLSS) concentrations and shorter hydraulic retention times.
• Clarification: Mixed liquor flows to 26 secondary clarifiers where biological floc settles.
• Performance: The secondary process ensures the effluent meets the “30/30” standard (30 mg/L BOD and 30 mg/L TSS) mandated by the Clean Water Act, typically achieving single-digit effluent values.

D. TERTIARY/ADVANCED TREATMENT (Demonstration)

While the main plant discharge is Secondary, the site hosts the Advanced Purification Center (APC). This 0.5 MGD demonstration facility tests the treatment train for the future Regional Recycled Water Program:

• Process: Membrane Bioreactor (MBR) → Reverse Osmosis (RO) → Ultraviolet/Advanced Oxidation (UV/AOP).
• Goal: To produce water suitable for groundwater recharge, meeting all Title 22 requirements.

E. DISINFECTION

Prior to ocean discharge, the secondary effluent is disinfected using sodium hypochlorite (bleach). The disinfected effluent enters the outfall system where rapid initial dilution occurs in the ocean environment.

F. SOLIDS HANDLING

Solids processing is a critical function at JWPCP, as it processes solids from its own liquid stream as well as solids returned from upstream water reclamation plants (the “sewershed” concept).

• Thickening: Waste Activated Sludge (WAS) is thickened using Dissolved Air Flotation (DAF) units.
• Digestion: Thickened sludge and primary sludge are pumped to 24 anaerobic digesters. These operate at mesophilic temperatures (~98°F) with a detention time of roughly 18 days. The digestion process reduces volatile solids by over 50% and produces methane gas.
• Dewatering: Digested biosolids are dewatered using high-speed centrifuges.
• Disposal/Reuse: The resulting “cake” is hauled off-site for composting (Class A biosolids) or energy recovery.

G. PROCESS CONTROL

The facility utilizes a centralized Distributed Control System (DCS) for real-time monitoring. The Cryogenic Oxygen plant requires specific, specialized automation to balance oxygen production with biological demand in the reactors.

4. INFRASTRUCTURE & FACILITIES

A. Physical Plant

The 420-acre site is effectively a small industrial city. It houses the Joint Administration Office (JAO), extensive maintenance shops, a comprehensive water quality laboratory, and the centralized dispatch for the entire sanitation district. The scale requires an on-site shuttle system for operators.

B. Energy Systems (Total Energy Facility)

JWPCP is a leader in the energy-water nexus. The Total Energy Facility (TEF) is a combined cycle power plant located on-site.

• Generation: The plant produces approximately 20 MW of electricity.
• Fuel Source: Digester gas is the primary fuel. The system uses gas turbines to generate electricity; waste heat from the turbines creates steam, which drives steam turbines for additional power and heats the digesters.
• Independence: The facility is generally energy self-sufficient and often exports surplus power to the local grid.

C. Odor Control

Given its location within the dense urban fabric of Carson, odor control is paramount. The facility uses a tiered approach: liquid phase treatment (chemical addition in sewers), containment (covered primary tanks and reactors), and vapor phase treatment (caustic scrubbers and activated carbon filters) treating over 300,000 cfm of foul air.

5. RECENT UPGRADES & MAJOR PROJECTS

The Clearwater Project (2019-2027)

• Project Scope: Construction of a new 7-mile, 18-foot internal diameter tunnel to convey treated effluent from JWPCP to the existing ocean outfalls at Royal Palms Beach.
• Project Budget: ~$630 Million (Construction phase)
• Drivers: The existing tunnels (built in 1937 and 1958) are aging and cross active fault zones. The new tunnel provides seismic resilience and capacity assurance.
• Technical Highlights: Utilization of a TBM (Tunnel Boring Machine) named “Rachel” to excavate through complex geological formations under the Palos Verdes Peninsula.
• Status: Tunneling is underway with completion expected by 2027.

Regional Recycled Water Program (RRWP)

• Project Scope: Development of a full-scale Advanced Water Purification Facility.
• Timeline: Pilot (2019-2022) -> Full Scale Planning (Current) -> Implementation (Est. 2028+).
• Goal: To purify up to 150 MGD of treated wastewater currently discharged to the ocean, making it one of the largest water recycling projects in the world.
• Budget: Projected $3.4 Billion for full build-out.
• Technical Highlights: The program successfully demonstrated the efficacy of MBR/RO/AOP processes on JWPCP effluent, paving the way for potable reuse applications.

JWPCP Effluent Pump Station Upgrade

• Scope: Replacement of aging pumping infrastructure to handle peak wet weather flows up to 1,200 MGD.
• Technology: Installation of new vertical turbine pumps and updated electrical switchgear.
• Status: Completed to ensure hydraulic reliability during extreme storm events.

6. REGULATORY COMPLIANCE & ENVIRONMENTAL PERFORMANCE

JWPCP operates under NPDES Permit No. CA0053813. Key compliance parameters include:

• BOD5: Monthly average limit of 30 mg/L (typically achieves < 15 mg/L).
• TSS: Monthly average limit of 30 mg/L (typically achieves < 10 mg/L).
• pH: Maintained between 6.0 and 9.0.
• Toxicity: Regular chronic toxicity testing ensures discharge does not harm marine life.

Environmental Stewardship: The transition to full secondary treatment in the early 2000s significantly aided the recovery of the Palos Verdes Shelf ecosystem. The Districts actively monitor marine life, sediment chemistry, and water quality around the outfalls.

7. OPERATIONAL EXCELLENCE

Staffing: The facility is staffed 24/7 by a team of over 200 professionals, including Grade V certified wastewater operators, electrical and instrumentation technicians, and stationary engineers for the power plant.

Performance Metrics:

• Energy Neutrality: JWPCP generates nearly 100% of its power needs.
• Uptime: The Cryogenic Oxygen plant maintains >99% availability critical for process stability.
• Biosolids Reuse: 100% of biosolids are diverted from landfills for beneficial reuse (composting or land application).

8. CHALLENGES & FUTURE PLANNING

Water Independence (Pure Water): The greatest strategic shift for JWPCP is the move from disposal to production. The Regional Recycled Water Program aims to recycle nearly all effluent, requiring massive capital investment and integration with the Metropolitan Water District of Southern California.

Climate Resilience: As an ocean-discharging facility, JWPCP must account for sea-level rise affecting hydraulic gradelines at the outfall. The Clearwater Project addresses seismic risks, but operational adaptations for changing storm intensities are ongoing.

Aging Infrastructure: With components dating back to the 1920s, asset management and rehabilitation of concrete structures degraded by biogenic sulfide corrosion remain a constant priority.

9. COMMUNITY & REGIONAL IMPACT

JWPCP is an economic anchor for the South Bay, employing hundreds of skilled tradespeople. The facility maintains the Bixby Marshland, a restored wetland area open to the public that demonstrates how urban infrastructure and nature can coexist. The Districts maintain active community advisory panels to ensure transparency regarding odors, construction impacts, and future development.

10. TECHNICAL SPECIFICATIONS SUMMARY

11. RELATED FACILITIES & RESOURCES

• Operating Authority: Los Angeles County Sanitation Districts
• Regulatory Agency: Los Angeles Regional Water Quality Control Board
• Related Project: The Clearwater Project Overview
• Facility Directory: Directory of California Treatment Plants

12. FAQ

Technical Questions

Q: Does JWPCP use conventional aeration?
A: No. JWPCP uses a High Purity Oxygen (HPO) system, which injects >90% pure oxygen into covered reactors, allowing for a smaller footprint and higher treatment efficiency.

Q: What is the energy profile of the plant?
A: JWPCP is energy neutral. It utilizes a Total Energy Facility (TEF) to convert biogas into electricity and steam, supplying virtually all the plant’s power needs.

Q: Is there tertiary treatment at JWPCP?
A: Currently, the main plant is Secondary treatment only. However, the Advanced Purification Center (APC) on-site is a demonstration facility producing 0.5 MGD of tertiary/advanced water.

Public Interest Questions

Q: How many people does JWPCP serve?
A: The facility serves approximately 5.5 million residents in Los Angeles County.

Q: Does the plant smell?
A: While wastewater naturally has an odor, JWPCP employs extensive odor control systems including covered tanks and chemical scrubbers to minimize impact on the surrounding Carson community.

Q: Where does the water go?
A: Treated water is discharged into the Pacific Ocean via tunnels and outfalls located off the Palos Verdes Peninsula.