Milwaukee Metropolitan Sewerage District Jones Island Water Reclamation Facility

FACILITY BASIC INFORMATION

• Plant Name: Jones Island Water Reclamation Facility (JIWRF)
• Location: Milwaukee, Milwaukee County, Wisconsin
• Operating Authority: Milwaukee Metropolitan Sewerage District (MMSD) / Contract Operations by Veolia Water Milwaukee
• Design Capacity: 300 MGD (Peak Hourly Treatment) / 123 MGD (Average Design)
• Current Average Flow: ~100 MGD (varies significantly with wet weather)
• Population Served: ~1.1 million (Total MMSD service area including South Shore)
• Service Area: 411 square miles (28 municipalities in Greater Milwaukee)
• Receiving Water Body: Lake Michigan (via Milwaukee Harbor)
• NPDES/WPDES Permit Number: WI-0036820
• Year Commissioned: 1925 (National Historic Civil Engineering Landmark)

1. INTRODUCTION

The Jones Island Water Reclamation Facility (JIWRF) is a globally recognized landmark in the history of environmental engineering and a critical component of the Milwaukee Metropolitan Sewerage District’s (MMSD) infrastructure. Located on a peninsula in the Milwaukee Harbor, Jones Island was one of the first facilities in the world to successfully implement the activated sludge process on a large scale upon its commissioning in 1925. Today, it remains a model of resource recovery, treating an average of roughly 100 million gallons per day (MGD) while converting biosolids into Milorganite®, a commercially sold organic fertilizer that has been on the market for nearly a century.

Operated under a public-private partnership with Veolia Water Milwaukee, the facility works in tandem with the South Shore Water Reclamation Facility and the 521-million-gallon Deep Tunnel system to serve over 1.1 million residents. Designated as a National Historic Civil Engineering Landmark by the ASCE, Jones Island combines historic architecture with modern wastewater technology to meet stringent Lake Michigan discharge limits while managing the hydraulic challenges of a combined sewer system.

2. FACILITY OVERVIEW

A. Service Area & Coverage

MMSD serves a 411-square-mile area covering 28 municipalities, including the City of Milwaukee and surrounding suburbs. The system is a mix of separate sanitary sewers and a historic Combined Sewer Area (CSA) located primarily in central Milwaukee and Shorewood. Jones Island is strategically positioned to handle the majority of the flow from the CSA. The collection system includes over 300 miles of interceptors and the “Deep Tunnel” Inline Storage System (ISS), which prevents overflows during heavy rain events.

B. Operational Capacity

Jones Island is designed to handle high operational variability due to the combined sewer network.

• Average Daily Flow: Approximately 80-100 MGD during dry weather.
• Peak Design Capacity: The plant is rated for a peak hourly flow of roughly 300 MGD for full secondary treatment.
• Blending Capacity: In extreme wet weather events, the facility can process additional flow through primary treatment and disinfection (blending) to protect the biological process from washout, though the goal is always full secondary treatment.

C. Discharge & Compliance

The facility discharges treated effluent directly into the Milwaukee Harbor, which flows into Lake Michigan. Under the Wisconsin Pollutant Discharge Elimination System (WPDES), the plant must adhere to strict limits regarding Phosphorus, TSS, and BOD to protect the Great Lakes ecosystem. Jones Island consistently achieves high compliance rates, frequently earning Peak Performance Awards from the National Association of Clean Water Agencies (NACWA).

3. TREATMENT PROCESS

Jones Island utilizes a conventional activated sludge process, but it is uniquely optimized for the recovery of nutrients to produce Milorganite fertilizer. This requires specific operational parameters that differ from plants focused solely on volume reduction.

A. Preliminary Treatment

Raw wastewater enters the facility via high-capacity interceptors and the Inline Storage System pump station.

• Screening: Coarse bar screens remove large debris (rags, wood, plastics) to protect downstream pumps.
• Grit Removal: Heavy inorganic materials (sand, gravel) are removed in grit chambers. This is particularly critical at Jones Island due to the combined sewer system which transports street runoff.

B. Primary Treatment

Flow proceeds to the primary clarification stage.

• Clarifiers: The plant utilizes a battery of circular primary clarifiers.
• Performance: These units settle out approximately 60-70% of Total Suspended Solids (TSS) and associated BOD.
• Odor Control: Primary effluent channels and weirs are covered or enclosed to manage odors, given the plant’s proximity to downtown Milwaukee.

C. Secondary Treatment (Activated Sludge)

This is the core of the Jones Island process.

• Aeration Basins: The facility operates large aeration basins using fine-bubble diffusion. The biology is maintained not just for water treatment, but to grow the specific microbial biomass required for fertilizer production.
• Nutrient Uptake: The process is operated to encourage the microbes to absorb nitrogen and phosphorus from the wastewater, concentrating these nutrients in the cell mass (sludge).
• Secondary Clarifiers: Mixed liquor settles in secondary clarifiers. The clear supernatant flows to disinfection, while the settled solids are either returned to the aeration tanks (RAS) or harvested as Waste Activated Sludge (WAS) for Milorganite production.

D. Disinfection

• Chlorination: The plant uses Sodium Hypochlorite for disinfection to kill pathogenic bacteria.
• Dechlorination: Before discharge into the harbor, Sodium Bisulfite is added to remove residual chlorine, preventing toxicity to aquatic life in Lake Michigan.
• Contact Time: Long serpentine channels ensure adequate contact time for effective pathogen inactivation.

E. Solids Handling & Milorganite® Production

Jones Island is unique in that it does not use anaerobic digestion. Instead, the focus is on preserving the nutrient value of the biosolids.

• Thickening: WAS is thickened to increase solids concentration.
• Dewatering: Belt filter presses squeeze water out of the sludge, creating a “cake.”
• Drying: The sludge cake is fed into large rotary drum dryers operating at temperatures up to 1,200°F (in the inlet). This process kills pathogens and produces dry, granular pellets.
• Product: The result is Milorganite (Milwaukee Organic Nitrogen), a slow-release fertilizer (6-4-0 NPK) sold throughout North America. Revenue from sales helps offset MMSD operational costs.

4. INFRASTRUCTURE & FACILITIES

A. Physical Plant

The facility occupies a distinct footprint on Jones Island, a peninsula separating the Kinnickinnic River from Lake Michigan. The site is characterized by its historic 1920s industrial architecture and the massive stack of the dryer facility. The plant shares the island with the Port of Milwaukee, requiring tight logistical coordination.

B. Energy Systems & Sustainability

Jones Island is a leader in renewable energy integration.

• Landfill Gas (LFG): A 19-mile pipeline transports LFG from the Emerald Park Landfill to Jones Island.
• Turbines: This gas fuels three Solar Turbines, generating electricity for the plant and heat for the sludge dryers.
• Impact: This system provides a significant portion of the plant’s energy needs and reduces the facility’s carbon footprint by utilizing waste methane.

C. Deep Tunnel Connection

While not physically “in” the plant, the Inline Storage System (ISS) is vital infrastructure. The ISS pump station at Jones Island can pump stored wastewater from the deep tunnel (300 feet below ground) up to the plant for treatment once peak flows subside, essentially flattening the hydrograph and preventing overflows.

5. RECENT UPGRADES & MAJOR PROJECTS

Harbor Siphons Capacity Expansion

• Project Scope: Expansion and rehabilitation of the siphon system that conveys sewage under the Milwaukee Harbor to the plant.
• Objective: To increase the hydraulic capacity of the conveyance system, allowing more flow to reach the plant during wet weather and reducing backups in the collection system.
• Technical Highlight: Involved complex marine construction and tunneling work to install new barrels while keeping existing siphons operational.

Milorganite Drying Facility Improvements

• Project Scope: Ongoing multi-phase replacement and rehabilitation of the rotary dryers and associated conveyance systems.
• Drivers: Aging infrastructure (some components dating back decades) and the need to maintain consistent fertilizer production.
• Results: Improved thermal efficiency, reduced dust generation, and increased reliability of the solids processing train.

Flood Protection & Climate Resilience

• Project Scope: Installation of improved flood walls and backflow prevention along the lake interface.
• Drivers: Rising Lake Michigan water levels and increased frequency of severe storms due to climate change.
• Results: Ensures the plant can continue operating during high-water events without hydraulic compromise.

6. REGULATORY COMPLIANCE & ENVIRONMENTAL PERFORMANCE

A. Permit Requirements

Operating under WPDES Permit WI-0036820, Jones Island faces some of the strictest discharge limits in the region due to the sensitive nature of Lake Michigan.

• Phosphorus: Strict limits (often < 0.6 mg/L) require chemical polishing (Ferric Chloride) and biological uptake optimization.
• Fecal Coliform: Seasonal limits to protect recreational water use in the harbor and lake.

B. Compliance History

Jones Island has an exemplary compliance record. The facility has received the NACWA Platinum Award for Peak Performance multiple times, indicating consecutive years of 100% permit compliance despite the challenges of managing a combined sewer system.

7. OPERATIONAL EXCELLENCE

The facility is staffed 24/7/365. The partnership between MMSD (owner) and Veolia Water Milwaukee (operator) allows for the leverage of global best practices. The operational strategy is uniquely dual-purpose: treating water to protect the lake and producing high-quality fertilizer. This requires operators to balance Mean Cell Residence Time (MCRT) and dissolved oxygen levels to favor specific biology that settles well and retains nutrients.

8. CHALLENGES & FUTURE PLANNING

A. Current Challenges

• Wet Weather Management: Despite the Deep Tunnel, extreme storms can still threaten system capacity. Managing the “first flush” of highly concentrated combined sewage is a constant operational focus.
• Aging Infrastructure: Maintaining a plant with structures dating to 1925 requires significant asset management and capital investment.
• PFAS/Emerging Contaminants: Like all WRFs, Jones Island is monitoring regulatory developments regarding PFAS, particularly how they might impact biosolids management and effluent standards.

B. 2050 Facilities Plan

MMSD is executing a long-range plan focusing on “integrated watershed management.” This moves beyond just grey infrastructure (pipes and plants) to green infrastructure (bioswales, permeable pavement) to reduce inflow and infiltration, ultimately easing the hydraulic load on Jones Island.

9. COMMUNITY & REGIONAL IMPACT

The economic impact of Jones Island is unique due to the Milorganite revenue stream, which returns millions of dollars annually to the District, helping stabilize rates for ratepayers. Furthermore, the plant’s performance is directly tied to the health of Milwaukee’s tourism economy, which relies heavily on a clean lakefront and river system.

10. TECHNICAL SPECIFICATIONS SUMMARY

11. RELATED FACILITIES

• South Shore Water Reclamation Facility: Located in Oak Creek, WI, this 300 MGD facility handles the southern portion of the MMSD service area and operates with anaerobic digestion.
• Inline Storage System (ISS): The “Deep Tunnel” system connecting both plants.
• Interplant Pipeline: Allows sludge transfer between Jones Island and South Shore for optimized processing.

12. FAQ SECTION

Technical/Professional Questions

1. Does Jones Island use anaerobic digestion?
No. Jones Island uses heat drying to produce Milorganite. Waste Activated Sludge is thickened, dewatered, and dried in rotary drums. This preserves the nitrogen content for the fertilizer.

2. How does the plant handle peak flows above 300 MGD?
Flows exceeding the secondary treatment capacity can be stored in the Deep Tunnel (ISS). If the tunnel fills, the plant utilizes blending (primary treatment + disinfection) or, in extreme cases, CSOs may occur, though these have been drastically reduced since the tunnel’s construction.

3. What is the role of the landfill gas pipeline?
A 19-mile pipeline delivers landfill gas from Emerald Park Landfill to Jones Island. This gas is burned in turbines to generate electricity and the exhaust heat is used in the sludge dryers, significantly reducing natural gas consumption.

Public Interest Questions

4. What is Milorganite?
Milorganite stands for “Milwaukee Organic Nitrogen.” It is a fertilizer made from heat-dried microbes that have digested the nutrients in the wastewater. It is safe, EPA-certified, and sold nationwide.

5. Does the plant smell?
MMSD invests heavily in odor control, covering clarifiers and using scrubbers on dryer exhaust. While occasional odors can occur, they are strictly monitored and managed.

6. Can I tour the facility?
Yes, MMSD offers tours of Jones Island to the public, schools, and professional groups, typically by appointment or during open house events like “Doors Open Milwaukee.”