Transforming Joliet: The Path to Sewer System Excellence

The City of Joliet, home to 150,000 residents, operates a vast wastewater infrastructure, including 610 miles of sewer mains, 50 lift stations, and three treatment facilities. Its aging sewer collection system includes combined and separate sewers, ranging from 8” to 72” in diameter, constructed of materials like PVC, VCP, and RCP. This infrastructure serves approximately 50,000 sewer connections but has faced significant challenges, including capacity issues, infiltration, and inflow (I/I), blockages, and structural degradation.

By 2014, SSES investigations revealed widespread structural deficiencies and operational challenges, highlighting an urgent need for rehabilitation. Each of the City’s three wastewater treatment plant (WWTP) basins faced distinct problems:

• Aux Sable Creek Basin: Newer construction but susceptible to groundwater infiltration.
• Westside Basin: H2S corrosion and I/I issues along the Rock Run Interceptor. 
• Eastside Basin: Aging infrastructure prone to blockages and collapses in the oldest parts of the City.

Exposed Aggregate and Reinforcement on Rock Run Interceptor

Faced with these issues, Joliet launched a bold 5-year comprehensive rehabilitation project, financed through an Illinois EPA (IEPA) loan. This initiative aimed to modernize infrastructure, restore system capacity and integrity, and to safeguard public health and environmental quality by reducing basement backups and sanitary and combined sewer overflows.

Basement Backups Before Project Initiation

With targeted inspections and phased rehabilitation, emphasizing cost-effective techniques like lining, grouting, and selective replacement, Joliet launched a proactive multi-year project to restore its collection system and safeguard public health and safety for decades to come.

BIG GOALS! Modernize infrastructure, restore system capacity and integrity, and to safeguard public health and environmental quality.

Building the Plan: Securing Buy-In and Funding

A Bold Vision

The City of Joliet’s ambitious sewer rehabilitation program required significant financial commitment and buy-in from stakeholders. The Public Service Committee was presented with a compelling case for approving the plan, grounded in the City’s strategic goals: eliminating sanitary sewer overflows (SSOs), reducing basement backups, lowering treatment costs, increasing treatment capacity, and restoring infrastructure integrity.

Key problem areas were highlighted, including Kerwin Estates, plagued by basement backups and frustrated residents; the Belmont Interceptor, with SSOs and capacity concerns; and other basins with severe maintenance and structural issues. 

Initial investigations uncovered over 2.5 million gallons per day of inflow and infiltration, with rehabilitation costs exceeding $3 million in these areas alone.

Leveraging Strategic Funding

To fund these efforts, the City proposed leveraging low-interest Illinois EPA (IEPA) loans, an attractive financial tool. Additionally, a customer rate study was underway, addressing the last rate increase from 2011. Proactive investment was presented as not only necessary but urgent:

• Adherence to Long-Term Control Plans & IEPA Mandates: Taking proactive measures would allow the City to control the scope, schedule, and fiscal impacts of projects, avoiding costly legal actions or consent decrees.
• Protection of Public Interests: Delaying action could result in sewer bills increasing to over $63/month (2% of Median Household Income).
• Support for Future Growth: These projects would ensure the City’s infrastructure could accommodate future demands.
• Cost-Effectiveness: Preventative maintenance, such as sewer lining, saves money long-term by avoiding expensive emergency repairs.

Ultimately, the City Council approved the plan in August 2016, enabling Joliet to proceed with critical infrastructure projects that balanced public interests, regulatory compliance, and future growth.

Building the Plan: Strategic Inspections Drive Solutions

With a city as large as Joliet, inspecting the entire sewer system within five years was not feasible. Instead, the City prioritized areas of greatest need and built a phased inspection plan, guided by a comprehensive Sanitary Sewer Evaluation Survey (SSES). Since 2014, this systematic approach has been instrumental in identifying and addressing sewer system issues.

Key components of the SSES include:

• Flow Monitoring: Subdividing basins to pinpoint areas of high inflow and infiltration (I/I), prioritize inspections, and understand how downstream sewers impact capacity.
• Hydraulic Modeling: Evaluating capacity constraints, determining the benefits of I/I reduction, and supporting decisions on rehabilitation versus upsizing.
• Manhole Inspections: Targeting public-sector contributors of I/I, especially in low-lying areas.
  Sewer Televising: Assessing structural integrity and identifying I/I locations.
• Smoke Testing: Pinpointing private-sector defects and indirect storm-to-sanitary sewer cross-connections where water infiltrates.
• 
• Dyed Water Flooding: Confirming and locating defects identified during smoke testing to guide repairs.
• Lateral Televising: Addressing extreme problem areas with as many lateral sewers as mainlines to prioritize for selective rehabilitation.
• Building Inspections: Uncovering illicit connections, particularly in neighborhoods with significant basement backup, I/I, and SSO issues.

This targeted inspection strategy ensured that the City focused resources on the most critical areas, providing a solid foundation for rehabilitation and construction efforts that followed.

Executing the Vision: Overcoming Challenges and Delivering Results

With the plan approved, the City of Joliet and RJN Group developed a clear road map to execute the ambitious 5-year project plan. The vision encompassed SSES inspections and rehabilitation efforts across 17 neighborhood areas, along with the rehabilitation or replacement of three major interceptors. The projected total investment of $34.35 million would address pressing issues in the collection system and lay the groundwork for long-term improvements.

The plan outlined a systematic approach, with work scheduled to begin early 2017 and conclude by 2022. Each year’s focus was strategically chosen to maximize impact, prioritize areas of greatest need, and balance resources effectively. The City aimed to demonstrate significant progress early in the project to maintain momentum and community support.

However, the execution phase was not without its challenges. The unforeseen global pandemic brought labor shortages, material delays, and supply chain disruptions. Inflation surged, compounding the costs and stretching budgets. Despite these obstacles, the City remained steadfast in its commitment to restoring and modernizing its sewer infrastructure.

Neighborhood Rehabilitation: A Multi-Phase Success Story

Comprehensive Phased Approach

As inspection work progressed, the rehabilitation phase began, with the city and RJN leveraging a phased approach that maximized impact, minimized disruption, and adhered to best practices. Each neighborhood’s unique needs were addressed through tailored bidding packages. This process evolved into a clear sequence of rehabilitation activities as shown on the graphic flowchart below.

This structured approach ensured efficient inflow and infiltration (I/I) removal while prioritizing quality and long-term performance. Below are the core elements of the rehabilitation approach:

• Point Repairs:
  • Focused on severe defects requiring excavation or advanced trenchless techniques.
  • Incorporated pre-construction documentation to minimize property impacts and ensure high-quality restoration, particularly in backyard easements.
• CIPP Mainline Sewer Lining:
  • A trenchless solution that forms a structural “pipe within a pipe” with a 50-year service life.
  • Delivered a cost-effective (~10% of sewer replacement) and durable solution to extend system life.
• Lateral Lining (T-Liners):
  • A trenchless method that provides a seamless seal at service connections, crucial for effective I/I reduction and structural integrity of the connections.
  • Addressed flow migration issues and ensured a comprehensive rehabilitation strategy.
• Grouting:
  • Reduced infiltration by sealing mainline joints and service connections with acrylamide grout following air testing.
• Manhole Rehabilitation:
  • Included structural wall repairs, inflow and infiltration sealing, structure adjustment and hydraulic improvements through bench and trough reconstruction.
  • Extended manhole lifespan by 25+ years.

Grouting of a Service Connection

Critical Success Factor: 
During the project, aggressive attention to NOT reinstating inactive or abandoned laterals through rigorous lateral investigation using televising and dye testing was critical in reducing I/I.

Key Accomplishments by Phase

The five-phase approach to neighborhood sewer rehabilitation brought measurable improvements to Joliet’s sewer infrastructure while directly addressing inflow and infiltration (I/I) issues. Guided by the city’s annual spending allocations from the IEPA loan, each phase tackled a unique set of challenges and delivered significant results. The figure below provides a map of the improvement areas.

Neighborhood Rehabilitation Areas

Below, the key accomplishments for each phase are shared, weaving in highlights that showcase the project’s impact.

Phase 1: 2017 Sewer System Rehabilitation

Budget: $5.82 Million

Neighborhoods Improved: Mayfair, Clearwater Springs, Aspen Falls, Kerwin Estates, Ridgewood, Parkwood, Parkhill, Edgecreek, Springview, Thunder Ridge, Bee Dee Highlands, and Chicago Street.

This inaugural phase laid the groundwork for success, employing comprehensive pre-construction assessments and advanced rehabilitation techniques.

Key Metrics:

• 123,000 LF of pre-construction cleaning, televising, and condition assessment, including 2,200 LF of arch sewer.
• 49,000 LF of CIPP lining (8”-18”), 623 manholes rehabilitated, and 148 lateral T-liners installed.
• Approximately 2,100 LF of geopolymer coating on large-diameter sewer lines.

Success Stories:

• In Ridgewood, post-rehabilitation flow monitoring revealed a remarkable 64% reduction in excess flows, validating the project’s proof of concept.
• In Kerwin Estates, 617,000 gallons per day (GPD) of I/I were identified. Following rehabilitation, backups and flooding significantly decreased, and critics of previous efforts became vocal supporters.

Phase 2: 2018 Sewer System Rehabilitation

Budget: $5.96 Million

Neighborhoods Improved: Benton & Washington, Forest Park, Parkview, Marycrest, and other locations.

Phase 2 extended the project’s reach, refining techniques and addressing priority sites:

Key Metrics:

• 90,000 LF of pre-construction cleaning and condition assessment.
• 70,000 LF of CIPP lining and 450 manholes rehabilitated.
• 10 point repairs and the rehabilitation of the Millsdale Lift Station to stop multiple leaks.

High-priority manholes near the Hollywood Casino & Hotel were successfully rehabilitated, preventing future leaks and enhancing system reliability in a critical area.

Phase 4: 2020 Sewer System Rehabilitation

Budget: $7.2 Million

Neighborhoods Improved: Marycrest and Reedswood.

Despite pandemic challenges, Phase 4 advanced the city’s rehabilitation efforts with notable achievements:

Key Metrics:

• 25,000 LF of pre-construction cleaning and televising.
• 58,000 LF of CIPP lining (8”-30”), 300 manholes rehabilitated, and 700 lateral T-liners installed.

Efficiency Spotlight: The grouting of 600 service connections played a vital role in reducing infiltration and extending system durability.

Phase 5: 2021 Sewer System Rehabilitation

Budget: $6.6 Million

Neighborhoods Improved: NE Areas 1 & 2, Raynor Park, Idylside, and Twin Oaks.

Phase 5 marked the project’s largest rehabilitation effort, achieving unprecedented results.

Key Metrics:

• 94,000 LF of pre-construction assessments and 78,000 LF of CIPP lining (8”-24”).
• 90 manholes rehabilitated, 475 lateral T-liners installed, and 729 service connections grouted.

Milestone Achievement: The project’s scope expanded to some of Joliet's oldest neighborhoods, tackling challenges in aging infrastructure and delivering substantial reductions in I/I.

Collapsing Service Connection in Twin Oaks

Critical Interceptor Upgrades: Protecting Joliet’s Backbone Infrastructure

In tandem with neighborhood sewer rehabilitation projects, two essential interceptor upgrades addressed critical sections of Joliet’s sewer system, safeguarding the city against high-consequence failures and enhancing capacity for future demands.

Phase 3a: Rock Run & West Park Interceptor Rehabilitation ($7.5M)

Spanning nearly 50,000 feet with diameters of 18” to 60”, the Rock Run and West Park Interceptors are vital conduits to the West Side WWTP. Multi-sensor inspections revealed severe deterioration, including visible aggregate and exposed reinforcement in the original RCP.

Key Highlights:

• Strategic Rehabilitation: Over 14,000 feet of CIPP lining (30”-48”) completed, extending the system’s life by 50 years.
• Complex Bypass System: A record-setting 9,000-foot bypass pumped up to 31 MGD during rain events, including a floated canal crossing designed in collaboration with the Army Corps of Engineers.
• Stakeholder Coordination: Navigated approvals and input from 10+ entities, including the Forest Preserve, FAA, and IDNR, while ensuring environmental protection with swamp mats and tree padding.
• Improved Reliability: Drastic reductions in SSOs and basement backups at historically problematic locations.

This phase stands out for its innovative engineering, exceptional stakeholder management, and seamless execution under challenging conditions.

Belmont Interceptor Construction

Phase 3b: Belmont Interceptor Replacement ($3M)

The Belmont Interceptor, a 50-year-old sewer located in a ravine, was undersized and inaccessible for maintenance. Flow modeling confirmed frequent surcharges, prompting a realignment to meet modern capacity and access standards. 

Key Highlights:

• Optimal Route Selection: Relocated 6,500 feet of sewer to a more accessible alignment along Maple Road (US Route 6), avoiding difficult terrain while minimizing excavation within state roads.
• Infrastructure Improvements: Installed a new 24” PVC sewer to accommodate increased flow, future maintenance needs, and tributary connections. 
• Budget Success: Delivered under budget by $700,000, overcoming utility conflicts, narrow workspaces, and low overhead clearances.
• Community-Centered Construction: Coordinated winter shutdowns to minimize traffic disruptions and ensure snowplow and school bus operations.

This project exemplifies cost-effective planning, community consideration, and engineering excellence, solving long-standing accessibility and capacity issues.

Innovation and Project Management Excellence

Innovative Design

The project exemplified forward-thinking innovation and adaptability:

Dynamic Specifications:

• Specifications were continuously refined to reduce change orders and improve outcomes, drawing lessons from prior projects.
• Polymer Concrete Manholes: For the first time, polymer concrete manholes were installed in high-corrosion areas downstream of force mains, delivering a 50-year life expectancy and setting a new standard for the City.
• Cost Efficiency and Trenchless Technology Advancements: By embracing various market products and prioritizing trenchless solutions, structural challenges were addressed without excavation, minimizing disruption and reducing costs.

City-Driven Success

The City of Joliet’s Utilities Services Department was instrumental in the project’s overall success. Their proactive approach and willingness to collaborate ensured the efficient execution of inspections and rehabilitation work.

• SSES Assistance:
  • Supported inspection activities by locating and cleaning manholes, jetting lines, televising sewers, conducting dye tests, and more.
  • Assisted with building inspections and minor repairs, expediting the SSES phase.

Defective Cleanout Found Smoke Testing

• Private Sector I/I Removal:
  • Complemented public sector efforts by targeting private property sources of I/I.
  • Actions included replacing cleanout caps, disconnecting downspouts and sump pumps, and addressing window well drains. 
• Point Repairs:
  • City crews completed over 50 pre-rehabilitation point repairs where feasible, optimizing contractor resources and funds.

The collaboration between the City and RJN set a benchmark for teamwork, innovation, and operational excellence in large-scale sewer rehabilitation projects. This partnership not only achieved technical success but also showcased an unwavering commitment to the community’s infrastructure and environmental future.

Managing a project of this duration, complexity, and magnitude required a blend of innovative tools and robust project management practices.

Leveraging Clarity®

One of the standout tools in this effort was RJN’s web-based application, Clarity. While it served as a powerful resource, its role was firmly rooted in improving efficiency and organization.

Centralized Data Management

Clarity provided a unified platform for all project data, from flow monitoring and CCTV televising to GIS mapping and dye testing results. This integration was pivotal in managing the project’s moving parts effectively:

• Design Phase: Clarity streamlined the design process by offering instant access to inspection data, all visualized on GIS maps. Engineers could quickly reference results from various investigations, enabling more precise design decisions.
• Bid Preparation: Providing free access to Clarity during the bidding phase allowed contractors to better understand the project scope, potentially reducing costs while enhancing their proposals’ accuracy.
• Construction Phase: Clarity’s daily reporting capabilities gave the city immediate insight into project progress. This transparency allowed stakeholders to make informed decisions swiftly and effectively.

By centralizing all project data, Clarity eliminated inefficiencies, reduced potential miscommunications, and contributed significantly to the project’s overall success.

Project Meetings and Teamwork

Structured Collaboration

The backbone of the project’s success was a series of biweekly meetings involving city staff, engineers, and contractors. These meetings served as an essential forum for:

• Issue Resolution: Teams could address emerging challenges in real time, aided by data and observations from Clarity.
• Proactive Planning: As new investigations were completed, meetings ensured the city could make immediate decisions, keeping the project on track.

Field Oversight

Both RJN and the city maintained an active field presence, conducting random checks and providing oversight during each project phase. This hands-on approach guaranteed that work met the required standards and progressed as planned.

Team Consistency and Trust

In a project spanning multiple years, maintaining consistency in key roles was critical. Despite inevitable changes in personnel and contractors, the consistent of meetings, always held at RJN’s offices in Joliet, established trust and fostered strong working relationships.

This commitment to collaboration and the innovative use of tools like Clarity exemplifies how successful project management can overcome the challenges of complex, long-term initiatives.

Lessons Learned: A Framework for the Future

Large, multi-year infrastructure projects like this one offer valuable opportunities for learning and refining processes. This experience with the City of Joliet has not only advanced project outcomes but also created a road map for improving future endeavors.

Data Management: The Foundation for Success

Data has been at the core of every project phase. Early challenges with varying data quality and accessibility drove the evolution of our processes:

• Improved Data Collection: Transitioning to higher-resolution GoPro photographs for manhole inspections provided clarity and reliability beyond initial methods.
• Centralized Access: Ensuring all data is stored in one accessible location (e.g., Clarity) allowed stakeholders to access information seamlessly, whether in the field, an office, or remotely—a crucial adaptation during the pandemic.

Reliable, well-organized data is essential for decision-making and progress tracking in complex projects.

Go-Pro Manhole Inspections in Online App (Clarity)

Optimizing Construction Contracts

Over time, the project team refined how construction contracts were written and awarded to enhance efficiency and results:

• Dynamic Specifications: Incorporating lessons learned, the design team regularly updated contract specifications to include new, tested products. Pilot testing, often offered free by manufacturers, allows for innovative solutions like LMK’s Cap-a-Connection.
• Collaborative Feedback: Sharing insights with manufacturers not only improved product performance but also led to co-developing solutions tailored to project needs.
• Balancing Cost and Expertise: Awarding contracts to experienced contractors—not solely the lowest bidder—ensured quality work and minimized project risks.

The Importance of Rigorous Testing

Rigorous testing and adherence to detailed specifications proved essential in ensuring project success:

• Post-Installation Testing: Ensuring liner thickness and physical properties met specifications for cured-in-place pipe (CIPP), manhole liners, and other materials helped maintain structural integrity and sealing performance.
• Results Over Perfection: While aesthetic perfection may not always be achievable, focusing on structural and sealing goals optimized costs without compromising functionality.

Embracing Trenchless Technologies

Innovative trenchless methods helped minimize excavation and restoration costs while pushing technological limits to meet project needs.

Delivering Robust Final Outputs

Final deliverables, such as as-builts, GIS updates, and a comprehensive CCTV database, were critical for keeping track of completed work. Additionally:

• Contractor Warranties: Ensuring warranties were tracked and accessible safeguarded against future issues.

Refining Rehabilitation Bidding

To address friction among contractors, the bidding approach was refined:

• Split Contracts: Separating rehabilitation work into distinct contracts for manhole/mainline lining and lateral lining reduced competition and improved project flow.
• Customized Approaches: Recognizing the pros and cons of single versus multiple contracts allowed us to adapt to project-specific needs effectively.

Reflections and Impact

Across all phases, the project addressed critical I/I and structural issues, modernized aging infrastructure, and garnered community support. The results speak for the project team:

Based on the success of this project, the City has continued the same approach to additional neighborhoods and has initiated the second 5-year project to continue to carry out the mission accomplished in the first five years.