Kansas City Kansas Board Of Public Utilities Nearman Creek Wastewater Treatment Plant

TARGET AUDIENCE

• Municipal consulting engineers evaluating SBR (Sequencing Batch Reactor) performance.
• Wastewater treatment plant operators and managers in the Midwest.

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• Regulatory compliance officers (KDHE/EPA Region 7).
• Developers and planners in the Wyandotte County western expansion zone.
• Environmental engineering students and researchers.

1. INTRODUCTION

The Wolcott Wastewater Treatment Plant (WWTP) serves as the critical sanitation infrastructure backbone for the rapidly expanding western corridor of Kansas City, Kansas. Situated near the confluence of the Missouri River and the Nearman Creek watershed, this facility is distinct from the older, larger Kaw Point facility that serves the historic city center. Operated by the Unified Government (UG) of Wyandotte County and Kansas City, Kansas, the plant manages wastewater for the economic engine of the county, including the Kansas Speedway, the Legends Outlets, and the burgeoning residential developments in the Delaware Ridge area.

Following a comprehensive overhaul and expansion in the late 2000s, the facility transitioned to advanced Sequencing Batch Reactor (SBR) technology, allowing it to produce high-quality effluent within a compact footprint. With a current design capacity of 4.5 MGD and scalable infrastructure to accommodate future growth, the Wolcott WWTP represents a model of modern, decentralized municipal treatment designed to meet the stringent discharge standards of the Kansas Department of Health and Environment (KDHE) while protecting the water quality of the Missouri River.

2. FACILITY OVERVIEW

A. Service Area & Coverage

The facility services the “Western Expansion Area” of Wyandotte County. Unlike the combined sewer systems found in older parts of Kansas City, the collection system feeding Wolcott is primarily separate sanitary sewers, reducing (though not eliminating) inflow and infiltration (I/I) issues. The service area encompasses:

• Commercial/Industrial: The Village West tourism district, Legends Outlets, Kansas Speedway, and light industrial parks.
• Residential: High-growth subdivisions in the Piper and Wolcott school districts.
• Geography: The rolling terrain of the Nearman Creek and Conner Creek watersheds, requiring a network of lift stations to convey flow to the river valley plant location.

B. Operational Capacity

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The plant was upgraded from a smaller lagoon/oxidation ditch system to a mechanical plant to handle the population boom of the mid-2000s. The current mechanical configuration allows for:

• Average Design Flow: 4.5 MGD
• Peak Hourly Flow: Up to 12.0 MGD
• Utilization: Currently operating at approximately 60-70% of average capacity, providing a safety buffer for ongoing development projects currently in planning phases by the Unified Government.

C. Discharge & Compliance

Treated effluent is discharged directly into the Missouri River. The facility operates under a National Pollutant Discharge Elimination System (NPDES) permit administered by the KDHE. Due to the high dilution factor of the Missouri River, limits are standard for secondary treatment, though strict monitoring for E. coli, Suspended Solids (TSS), and Biochemical Oxygen Demand (BOD) is enforced. The plant has maintained a strong record of compliance, earning Peak Performance Awards from the National Association of Clean Water Agencies (NACWA).

3. TREATMENT PROCESS

The Wolcott WWTP utilizes a Sequencing Batch Reactor (SBR) configuration. This batch-treatment process combines aeration and sedimentation in the same tank, eliminating the need for separate secondary clarifiers and return activated sludge (RAS) pumping systems found in conventional flow-through plants.

A. PRELIMINARY TREATMENT (Headworks)

Raw wastewater enters the headworks building where it undergoes rigorous physical separation to protect downstream mechanical equipment:

• Screening: Fine mechanical bar screens remove rags, plastics, and large debris. Screenings are washed, compacted, and disposed of in landfills.
• Grit Removal: A vortex grit removal system separates heavy inorganic solids (sand, coffee grounds, eggshells) using centrifugal force. This prevents abrasion on pumps and volume loss in the SBR basins.

B. SECONDARY TREATMENT (SBR Process)

The core of the treatment occurs in the SBR basins. The plant utilizes a multi-basin configuration to handle continuous inflow while operating in batch modes. The SBR cycle consists of four distinct phases:

1. Fill: Wastewater enters the basin and mixes with the biomass (mixed liquor). Depending on the operational mode (anoxic or aerated fill), this stage can facilitate denitrification.
2. React (Aeration): Fine bubble diffusers provide oxygen to the bacteria, facilitating the biological breakdown of organic matter (BOD) and nitrification (conversion of ammonia to nitrate).
3. Settle: Aeration and mixing stop, allowing the biomass to flocculate and settle to the bottom of the tank, creating a clear supernatant layer at the top.
4. Decant: A floating decanter mechanism lowers into the clear water zone to draw off the treated effluent without disturbing the settled sludge blanket.

C. DISINFECTION

Following the SBR decant phase, the effluent flows to the disinfection facility:

• Technology: Ultraviolet (UV) Disinfection.
• Process: The water passes through channels containing banks of UV lamps. The UV light penetrates the cell walls of pathogens (bacteria and viruses), disrupting their DNA and preventing replication.
• Benefit: Unlike chlorination, this process requires no hazardous chemical storage and produces no disinfection byproducts (DBPs) or residual chlorine toxicity in the Missouri River.

D. SOLIDS HANDLING

Waste Activated Sludge (WAS) is removed from the SBR basins during the settle or decant phase to maintain the target Solids Retention Time (SRT).

• Stabilization: Sludge is pumped to aerobic digesters where it undergoes further aeration to reduce volatile solids and vector attraction.
• Dewatering: Digested biosolids are dewatered using high-performance centrifuges or belt filter presses to produce a “cake” solid.
• Disposal: The dewatered Class B biosolids are typically land-applied on permitted agricultural fields as a soil amendment, recycling nutrients back into the local ecosystem.

E. SCADA & CONTROLS

The facility is highly automated via a Supervisory Control and Data Acquisition (SCADA) system. This allows operators to adjust SBR cycle times based on influent flow conditions (e.g., storm mode) and monitor dissolved oxygen levels, tank levels, and equipment status remotely.

4. INFRASTRUCTURE & FACILITIES

A. Physical Plant

The site is strategically located in the river floodplain, protected by levee systems. The layout includes the Headworks Building, SBR Basins (open air), Blower Building, UV/Effluent Structure, and a Solids Handling/Administration Building. The architecture is utilitarian industrial, designed for durability against Midwest weather extremes.

B. Energy Systems

As a major energy consumer, the plant relies on power provided by the Kansas City Board of Public Utilities (BPU).

• Aeration Efficiency: The use of Variable Frequency Drives (VFDs) on the aeration blowers allows the plant to match oxygen supply strictly to biological demand, serving as the primary energy conservation measure.
• Backup Power: Large diesel generators ensure continuous operation of critical pumps and disinfection systems during grid outages.

C. Odor Control

Given the proximity to developing areas, odor control is a priority. The headworks building is enclosed and ventilated through activated carbon scrubbers or biofilters to treat hydrogen sulfide ($H_2S$) and other odorous compounds before venting to the atmosphere.

5. RECENT UPGRADES & MAJOR PROJECTS

Western Expansion & Modernization (Completed ~2010)

• Project Scope: Complete replacement of legacy lagoon/oxidation ditch systems with mechanical SBR treatment.
• Budget: Approx. $30-$40 Million (part of broader system improvements).
• Drivers: Regulatory compliance (effluent quality) and capacity expansion for the “Village West” development (NASCAR, MLS Stadium, Legends).
• Technical Highlight: Implementation of SBR technology provided a smaller footprint and better nutrient removal capabilities than conventional activated sludge.

Ongoing Collection System Improvements (2020-2025)

• Scope: Upgrades to the Conner Creek and Nearman Creek interceptor sewers and lift stations.
• Funding: Revenue bonds and State Revolving Funds (SRF).
• Objective: To eliminate sanitary sewer overflows (SSOs) during high wet-weather events and convey flows efficiently to the Wolcott plant.

Future Nutrient Removal Planning

While the Missouri River has high assimilation capacity, the Unified Government monitors evolving KDHE regulations regarding Nitrogen and Phosphorus. The SBR design at Wolcott is inherently capable of Biological Nutrient Removal (BNR) through the adjustment of cycle times (increasing anoxic periods), providing a future-proof operational strategy without massive capital construction.

6. REGULATORY COMPLIANCE

Permit Requirements (General Profile)

The facility operates under Kansas Water Pollution Control Permit requirements typical for discharge to a large river system:

• BOD5: Monthly average limit approx. 30 mg/L.
• TSS: Monthly average limit approx. 30 mg/L.
• E. coli: Seasonal limits (April-October) for recreational contact protection.
• pH: Maintained between 6.0 and 9.0.

Environmental Stewardship

The Unified Government has implemented aggressive Industrial Pretreatment Programs (IPP) to ensure that commercial discharges from the Speedway area and light industry do not upset the biological balance of the Wolcott plant. This protection is vital for the SBR process, which can be sensitive to toxic shock loads.

7. CHALLENGES & FUTURE PLANNING

A. Growth Management

The primary challenge for the Wolcott facility is the unpredictability of development in western Wyandotte County. Large commercial venues create “peaking” events (e.g., race days or soccer matches) that send surges of wastewater to the plant. The SBR system’s ability to buffer flow in the tanks helps manage these hydraulic peaks.

B. Flood Resilience

Located near the Missouri River, flood risk management is a constant operational reality. Maintaining levee integrity and ensuring pump station reliability during high river stages is a critical aspect of the facility’s disaster preparedness plan.

C. Workforce Development

Like many utilities, the UG faces the challenge of replacing retiring senior operators. The complexity of SBR automation requires operators with strong technical and computer skills (SCADA proficiency) in addition to biological process knowledge.

8. TECHNICAL SPECIFICATIONS SUMMARY

9. FAQ SECTION

Technical Questions

Q: What is the difference between the BPU and the Unified Government regarding this plant?
A: The Kansas City Board of Public Utilities (BPU) provides electric power and potable water to the site. The Unified Government (UG) Water Pollution Control Division actually operates the wastewater treatment plant and collection system.

Q: Why was SBR technology chosen for this location?
A: SBRs offer a compact footprint and the ability to handle variable flows and loads—ideal for a developing area with specific “event-based” flow peaks from nearby entertainment districts.

Q: Does the plant perform nutrient removal?
A: The SBR process is capable of nitrification and denitrification through cycle adjustment. While strict limits may not be in the current permit due to the Missouri River’s size, the plant is operationally ready for Biological Nutrient Removal (BNR).

Public Interest Questions

Q: Does the plant smell?
A: The facility utilizes covered headworks and odor control scrubbers to minimize odors. Under normal operations, odors are contained within the fence line.

Q: Where does the water go after treatment?
A: After treatment and disinfection, the clean water (effluent) is discharged into the Missouri River, returning to the natural water cycle.