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Understanding how Chicago's underground construction review works

2019 0108 Ideas Post
Jan 08, 2019

If you are building in Chicago you may have to take part in the OUC process. The Office of Underground Coordination is a group of representatives from 27 public agencies and private companies, including the Chicago Transit Authority, gas and electric utilities, telecom, and broadband companies, led by staff at the Chicago Department of Transportation.

MAP Strategies excels at leading our clients – developers, architects, and contractors – through this process to ensure on-time permitting of their projects.


OUC, formerly known as the Bureau of Underground, was established in 1994 to share knowledge about the complex layers of surface and underground infrastructure in Chicago. The need for this kind of coordination was made evident in April 1992 when a crew digging in the Chicago River struck an old freight tunnel, spilling thousands of gallons of water. The tunnels flooded and spread water into the basements of two dozen Loop buildings.

While created to prevent another disaster, the more common purpose of the OUC is to coordinate adjacent or conflicting projects to minimize disruptions in a public way and avoid redundant excavations and surface restorations.


There’s a wide variety of construction actions that require participating in the OUC process, which includes excavating in a public way, excavating or boring in the Freight Tunnel System Area, and maintenance in existing vaults. Projects requiring OUC review are detailed here.

Breaking down the OUC process

The process first starts with Information Retrieval (IR), which provides the builder with information about what exists underground. It could be the Blue Line subway, sewers, fiber optic lines, and freight tunnels. These are commonly submitted by surveyors and civil engineers, but MAPS can also submit a request on your behalf when you are researching a new site.

Applicants submit a request indicating the location and scope of planned work to the OUC which will share the request with its members. Each member will respond with a drawing of their infrastructure in the planned work area or indicate that they have no conflicts or concerns regarding the area of work. OUC members meet weekly.

Once the builder has designed their project based on the information they received in the IR process, they will have to submit construction drawings to the OUC to start the Existing Facility Protection (EFP) process. OUC will forward the application and construction drawings to the members. Again, the members will review and respond within 15 or 30 days depending on the project type.

The best case scenario in the EFP process is to receive "not involved" or "permit issuance authorized" responses, meaning OUC members haven't found any conflicts between the project and their infrastructure. When that milestone is reached for all reviewers, and all outstanding payments have been completed, OUC will issue a Permit Issuance Authorization Letter. Depending on the scope of work, this may be required by the Department of Buildings or other Chicago Department of Transportation (CDOT) sections for permit issuance.

If there's a conflict, OUC members will provide information on how to protect their infrastructure. Utilities typically provide a copy of their infrastructure “atlas” locating the conflict or they will describe the conflict in a narrative.

When the project has gotten approvals from all of the members and permits have been issued, don't forget to contact DIGGER prior to starting work!

MAPS has ushered dozens of projects through the two OUC processes (IR and ERP) and can assist its clients to prepare applications with the minimum amount of potential conflicts.

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