City Of Columbus Jackson Pike Wastewater Treatment Plant

FACILITY BASIC INFORMATION

Plant Name: Jackson Pike Wastewater Treatment Plant

Location: 2104 Jackson Pike, Columbus, Franklin County, Ohio

Operating Authority: City of Columbus, Department of Public Utilities (Division of Sewerage and Drainage)

Design Capacity: 68 MGD (Average Daily Flow) / 102 MGD (Peak Secondary) / 150 MGD (Peak Hydraulic with CEPT)

Current Average Flow: ~60-65 MGD

Population Served: Approx. 650,000 (part of the 1.2M regional system)

Service Area: Central and southern Columbus, Grove City, Urbancrest, and contracting suburbs

Receiving Water Body: Scioto River

NPDES Permit Number: 4PF00000

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Year Commissioned: 1937 (Major expansions in 1950s, 1970s, 2000s)

The Jackson Pike Wastewater Treatment Plant (WWTP) is one of two primary wastewater treatment facilities serving the Columbus metropolitan area, operating in tandem with the Southerly WWTP. Strategically located along the Scioto River, this facility is a cornerstone of the region’s “Blueprint Columbus” initiative, managing wastewater for the central and southern portions of Franklin County. Commissioned originally in 1937, the plant has evolved from a basic treatment facility into a sophisticated 68-MGD complex capable of handling significant wet-weather events through advanced Chemically Enhanced Primary Treatment (CEPT).

Operated by the City of Columbus Division of Sewerage and Drainage (DOSD), Jackson Pike plays a vital role in maintaining the water quality of the Scioto River watershed. Following over $300 million in cumulative capital improvements over the last two decades, including the installation of a Cogeneration facility and extensive wet-weather capacity upgrades, the plant represents a balance of historical infrastructure and modern process engineering. It serves as a critical compliance asset under the city’s Consent Decree with the Ohio EPA to mitigate Combined Sewer Overflows (CSOs).

FACILITY OVERVIEW

A. Service Area & Coverage

The Jackson Pike WWTP serves a dense, urbanized service area encompassing approximately the central and southwestern quadrants of the Greater Columbus region. This includes the downtown central business district, The Ohio State University campus area, and the municipalities of Grove City and Urbancrest. The collection system feeding Jackson Pike is a mix of separate sanitary sewers and older combined sewers, presenting unique hydraulic challenges during precipitation events. The facility is linked hydraulically to the Southerly WWTP via an Interconnector Sewer, allowing for load balancing and sludge transfer between the two massive facilities.

B. Operational Capacity

The facility is designed for an Average Daily Flow (ADF) of 68 Million Gallons per Day (MGD). However, its hydraulic profile is engineered to manage extreme variations due to the combined sewer system it serves. The plant utilizes a tiered capacity approach:

• Secondary Treatment Capacity: Up to 102 MGD through the full biological train.
• Wet Weather Capacity: Utilizing Chemically Enhanced Primary Treatment (CEPT) and bypass routing, the plant can treat up to 150 MGD to primary standards during storm events, blending this with secondary effluent prior to disinfection to meet permit limits.

C. Discharge & Compliance

Treated effluent is discharged into the Scioto River (Outfall 001) immediately south of the facility. The plant operates under Ohio EPA NPDES Permit No. 4PF00000. Due to the Scioto River’s classification and low dilution ratio during dry months, the plant must meet stringent limits for Carbonaceous Biochemical Oxygen Demand (CBOD), Total Suspended Solids (TSS), Ammonia-Nitrogen, and E. coli. The facility has maintained a robust compliance record, frequently receiving National Association of Clean Water Agencies (NACWA) Peak Performance Awards.

TREATMENT PROCESS

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The Jackson Pike WWTP utilizes a conventional activated sludge process augmented by high-rate primary treatment strategies for wet weather flows. The liquid stream process ensures the removal of organics, solids, and pathogens before discharge.

A. Preliminary Treatment

Raw wastewater enters the headworks where it passes through mechanically cleaned bar screens (typically 1/2 to 3/4 inch opening) to remove large debris, rags, and plastics. Following screening, flow enters aerated grit chambers. These chambers reduce the velocity of the wastewater and introduce air to separate inorganic solids (sand, gravel, eggshells) from organic matter. The grit is settled, removed, washed, and disposed of at a sanitary landfill. Odor control at the headworks is managed via chemical wet scrubbers and biofilters to mitigate nuisance odors for nearby communities.

B. Primary Treatment & CEPT

The facility employs rectangular primary settling tanks fitted with chain-and-flight sludge collectors. Under normal dry-weather conditions, gravity settling removes approximately 60-70% of TSS and 30-35% of BOD.

Chemically Enhanced Primary Treatment (CEPT): During high-flow wet weather events, the plant activates its CEPT mode. Metal salts (typically Ferric Chloride) and anionic polymers are injected prior to the primary clarifiers. This coagulation and flocculation process significantly increases the settling velocity of particles, allowing the primary tanks to handle higher hydraulic loading rates while maintaining removal efficiencies. This is a critical component of the plant’s strategy to minimize CSO events.

C. Secondary Treatment

The biological treatment stage utilizes a conventional Plug Flow Activated Sludge process.

• Aeration Basins: The settled primary effluent flows into multiple aeration passes. The facility uses fine-bubble membrane diffusers to transfer oxygen to the mixed liquor, supporting the biomass that consumes organic pollutants and converts ammonia to nitrate (nitrification).
• Secondary Clarifiers: Mixed liquor flows to circular secondary clarifiers where the biological floc settles. Ideally, the clear supernatant overflows the weirs.
• RAS/WAS: Settled sludge is returned to the aeration tanks (Return Activated Sludge – RAS) to maintain the biological population. Excess growth is removed as Waste Activated Sludge (WAS) and sent to solids handling.

D. Disinfection

Jackson Pike currently utilizes chemical disinfection rather than UV.

• Chlorination: Sodium hypochlorite is dosed into the secondary effluent to inactivate pathogens (E. coli/Fecal Coliform).
• Dechlorination: Before discharge to the Scioto River, sodium bisulfite is added to remove residual chlorine, protecting aquatic life in the receiving water body from chlorine toxicity.

E. Solids Handling & Energy Generation

The solids handling strategy at Jackson Pike is integrated with the larger Columbus system.

• Thickening & Digestion: Primary sludge and WAS are thickened (gravity thickening for primary, dissolved air flotation or centrifugation for WAS) and fed into anaerobic digesters.
• Anaerobic Digestion: The solids undergo mesophilic anaerobic digestion, reducing volatile solids and pathogen content while producing methane-rich biogas.
• Cogeneration (CHP): The biogas produced is scrubbed and utilized in an on-site Combined Heat and Power (CHP) facility. This system generates electricity to offset plant power consumption and provides heat for the digesters.
• Final Disposal: While Jackson Pike has digestion capabilities, the bulk of the stabilized solids are pumped via the Interconnector Sewer to the Southerly WWTP for dewatering and incineration. This centralization of final disposal allows for economies of scale in incineration operations.

INFRASTRUCTURE & FACILITIES

A. Physical Plant

The site occupies over 110 acres along the west bank of the Scioto River. The facility layout reflects decades of expansion, with older architectural styles blending with modern industrial structures. Key structures include the Administration Building (housing SCADA control and labs), the Screen Building, the Blower Building, and the distinctive anaerobic digester complexes.

B. Energy Systems

Wastewater treatment is energy-intensive, particularly the aeration blowers. Jackson Pike addresses this through its Biogas Cogeneration Facility.

• CHP Capacity: The system utilizes internal combustion engines fueled by digester gas.
• Sustainability: The CHP system significantly reduces the plant’s reliance on the electrical grid and lowers the carbon footprint by utilizing methane that might otherwise be flared.
• Energy Efficiency: Upgrades to turbo blowers and fine bubble diffusion in the aeration basins have reduced the specific energy consumption (kWh/MG) for secondary treatment.

C. Odor Control

Given the plant’s proximity to I-71 and residential areas in Grove City and South Columbus, odor control is a priority. The facility utilizes packed tower scrubbers using bleach and caustic soda at the headworks and primary sludge pumping stations. Additionally, covers are utilized on specific process tanks to capture foul air for treatment.

RECENT UPGRADES & MAJOR PROJECTS

The City of Columbus has invested heavily in Jackson Pike to meet Consent Decree requirements and modernize aging assets.

1. Chemically Enhanced Primary Treatment (CEPT) Implementation (2010s)

• Project Scope: Installation of chemical storage (ferric chloride and polymer), metering pumps, and rapid mix induction units upstream of primary clarifiers.
• Driver: The need to process peak wet weather flows up to 150 MGD without washing out the secondary biomass, thereby reducing bypasses.
• Result: Successfully allows the plant to treat high hydraulic loads, removing significant TSS and BOD in the primary stage during storms.

2. Digester Gas Utilization & CHP Project

• Project Scope: Installation of gas conditioning systems and cogeneration engines. construction of a new energy center.
• Funding: Financed through Water Pollution Control Loan Fund (WPCLF) and local revenue bonds.
• Technical Highlights: The system allows the plant to generate a portion of its own electricity and heat, insulating the utility from energy price volatility.

3. Lower Olentangy Tunnel (LOT) – (System-Wide Impact)

• Status: Construction Ongoing/Near Completion (2021-2026 timeframe)
• Budget: ~$250+ Million
• Relevance: While a conveyance tunnel, the LOT connects to the Jackson Pike influent structure. It is designed to capture overflows from the Olentangy River area and convey them to Jackson Pike for treatment, smoothing out peak influent spikes and reducing CSOs.

Current/Upcoming Projects (2024-2027)

• Aeration System Improvements: ongoing replacement of aging diffusers and blower optimization.
• Electrical Distribution Upgrades: Modernization of high-voltage switchgear to ensure reliability.
• Sludge Thickening Upgrades: Improvements to WAS thickening technologies to increase solids concentration prior to digestion.

REGULATORY COMPLIANCE & ENVIRONMENTAL PERFORMANCE

A. Permit Requirements

Under NPDES Permit 4PF00000, Jackson Pike faces strict limits. The Scioto River is a sensitive water body, requiring high-level nitrification (ammonia removal). Typical summer limits include:

• CBOD5: 8.0 – 10.0 mg/L (Monthly Avg)
• TSS: 12.0 mg/L (Monthly Avg)
• Ammonia-N: 1.0 – 1.5 mg/L (Summer)
• E. coli: 126/100ml (Geometric Mean)

B. Compliance History

The facility operates under a Consent Decree negotiated between the City of Columbus and the State of Ohio/US EPA to address wet weather overflows. While the plant generally meets dry weather permit limits with high consistency, the primary regulatory focus remains on managing wet weather volume and eliminating sanitary sewer overflows (SSOs) in the collection system.

C. Environmental Stewardship

The effluent from Jackson Pike constitutes a significant portion of the Scioto River’s base flow during dry summer months. As such, the plant is critical for maintaining dissolved oxygen levels in the river to support aquatic life. The plant’s biosolids program (via Southerly) ensures that waste solids are disposed of safely, typically through incineration with energy recovery or landfilling ash.

OPERATIONAL EXCELLENCE

A. Staffing

The facility is staffed 24/7/365. It employs a team of State of Ohio Certified Wastewater Operators. Management and shift supervisors typically hold Class III or Class IV wastewater certifications, the highest levels in the state.

B. Technology & Control

The plant utilizes a centralized SCADA (Supervisory Control and Data Acquisition) system. This allows operators to monitor dissolved oxygen levels, tank levels, pump status, and chemical feed rates in real-time. The system is integrated with the city’s rain gauge network to anticipate wet weather flows and pre-activate CEPT protocols.

CHALLENGES & FUTURE PLANNING

A. Wet Weather Management

The primary engineering challenge remains the “flashy” nature of the Scioto River watershed. Heavy rainfall causes rapid spikes in influent flow. The “Blueprint Columbus” initiative aims to address this not just at the plant, but through Green Infrastructure (rain gardens, permeable pavement) in the collection system to reduce inflow and infiltration (I/I) before it reaches Jackson Pike.

B. Aging Infrastructure

With original structures dating to 1937, asset management is a constant battle. Concrete rehabilitation in clarifiers and replacement of underground piping galleries are ongoing maintenance capital expenditures.

C. Future Nutrient Limits

Regulatory trends in Ohio suggest tighter future limits on Total Phosphorus and Total Nitrogen to combat harmful algal blooms (HABs) in the watershed and downstream. Future master planning for Jackson Pike evaluates the feasibility of Biological Nutrient Removal (BNR) upgrades, should the permit limits become more stringent.

TECHNICAL SPECIFICATIONS SUMMARY

RELATED FACILITIES

Southerly Wastewater Treatment Plant: Jackson Pike’s sister facility, located further south on the Scioto River. It is larger (114 MGD Avg Design) and houses the solids incineration complex for both plants.

Interconnector Sewer: A critical large-diameter gravity and force main system that connects Jackson Pike and Southerly, allowing for flow diversion and sludge transfer.

Compost Facility: The City operates a compost facility (Com-Til) that utilizes some biosolids (historically) and yard waste to create soil amendments, though incineration is the primary disposal method currently.

FAQ SECTION

Technical Questions

1. What is the difference between dry weather and wet weather capacity at Jackson Pike?
The plant is designed to treat 68 MGD on average. However, during wet weather, it can process up to 102 MGD through secondary treatment. Flows between 102 MGD and 150 MGD receive Chemically Enhanced Primary Treatment (CEPT) and disinfection before blending, preventing washout of the biological mass.

2. Does Jackson Pike utilize Biological Nutrient Removal (BNR)?
The plant achieves nitrification (ammonia removal) consistently. While it does not have a formal BNR configuration for Total Nitrogen or Phosphorus removal currently, it utilizes chemical addition for phosphorus precipitation when necessary to meet limits.

3. How is the sludge managed?
Sludge is thickened and anaerobically digested at Jackson Pike to reduce volume and produce biogas. The stabilized sludge is then pumped via the Interconnector Sewer to the Southerly WWTP, where it is dewatered and incinerated.

Public Interest Questions

4. Does the plant smell?
Like all wastewater facilities, odors can occur. However, Jackson Pike employs extensive chemical scrubbers and biofilters at the headworks and primary tanks to scrub foul air before it is released, minimizing impact on neighbors.

5. Can I tour the facility?
The City of Columbus Division of Sewerage and Drainage occasionally offers tours for educational groups and industry associations. Contact the Department of Public Utilities for current availability.