Client: Illinois Tollway

The Illinois Tollway planned to widen the Central Tri-State (I-294) to five lanes. To make room for this expansion, the sanitary sewers that lead into the Flagg Creek Water Reclamation District (FCWRD) plant needed to be moved outside of the new roadway area. Clark Dietz was responsible for managing this complex task, providing construction oversight, and ensuring the safe and efficient relocation of two major sewer lines.

What We Did:

This image depicts a construction site along a roadway, showing excavation work and drainage infrastructure.

  1. Deep Excavation and Sewer Installation
    We oversaw the installation of sewer pipes that were buried more than 20 feet underground. Some of this work was done through solid bedrock, and different techniques like trenching, jacking, and boring were used to move the pipes safely under the busy tollway.

  2. Managing Waterways
    Since the sewer lines crossed creeks and other waterways, we used special equipment called cofferdams to divert the water and make room for excavation without disturbing the environment.

  3. Jacking Pipes Under the Tollway
    In some areas, especially under the busy I-294, we had to install long pipes—up to 400 feet long—directly under the road without disturbing traffic. This involved jacking pipes into place, which required precise engineering to avoid any settling or damage to the roadway above.

  4. Handling Challenging Ground Conditions
    Throughout the project, we encountered difficult ground conditions, including large boulders and hard bedrock. These obstacles sometimes slowed down progress, but we managed the contractor’s work to ensure that it stayed on track.

  5. Waste Removal and Earth Excavation
    During the project, we removed around 8,000 tons of waste material and dug out over 8,500 cubic yards of earth to make space for the new sewer system.

  6. Creating a Safe Path for Pedestrians
    To keep pedestrians safe during construction, we built a new, protected 6-foot wide multi-use path, which allowed people to continue using the area while work was underway.

Key Project Highlights:

  • Over 2,000 feet of new sewer pipe installed below the tollway, some using methods like trenching and jacking under active lanes of traffic.

  • Managed the relocation of sewers while bypassing water bodies with cofferdams.

  • Installed seven jacked pipes, including the longest run of over 400 feet under I-294.

  • Handled unexpected challenges like large boulders and bedrock during construction.

  • Removed 8,000 tons of waste and excavated 8,500 cubic yards of soil.

  • Created a safe, protected pedestrian path for the community.

This image shows a pathway running alongside a chain-link fence next to a large retaining wall or noise barrier. The wall appears to be part of highway infrastructure, with a sloped embankment and an excavator working near the top.

Clark Dietz’s Impact:

Clark Dietz’s team brought specialized expertise in handling deep underground sewer work. Our approach ensured that there was no settlement or disruption during the sewer relocation process, keeping the tollway and surrounding areas safe. Additionally, we made sure to keep the contractor on track and addressed any obstacles that came up during construction.

Recognition:

“Flagg Creek Water Reclamation District was pleased to have worked with Clark Dietz on this major sewer relocation work required by the Illinois Tollway for the I-294 Expansion Project. This work required a high degree of partnering between design, construction and operations, and Clark Dietz’s construction engineering team was always helpful, competent and professional, making this project a success,”
says James Liubicich, P.E., Executive Director for Flagg Creek Water Reclamation District.