DB Sterlin performed a full topographic survey from ROW to ROW for various streets, including all surface features, and performed a complete utility investigation of all sanitary and storm manholes, inlets and catch basins to collect pipe size, material, direction, and measure down for each visible pipe, as well as set control points and permanent benchmarks. DB Sterlin used State Plane Coordinates and City of Chicago Datum for the controls. In addition, DB Sterlin performed detailed ADA surveys on each corner that required a new compliant ADA ramp, and designed all the ramps within the project limits following the latest CDOT ADA Survey and Design Criteria. Furthermore, Maintenance of Traffic (MOT) drawings were prepared where the construction work required rerouting and/or closing sections of the road.
The scope of services for this project consisted of the survey and design work for the preparation and completion of the sewer and ADA replacement at several locations throughout the City of Chicago. The City of Chicago currently has over 4,400 miles of sewer mains and 340,000 ancillary structures, a quarter of which is over 100 years old. Some of the original mains were originally installed between 1856 and 1920. Over the next 10 years, the city plans on replacing over 750 miles of sewer mains and reconstructing over 160,000 catch basins. The proposed project is to remove the existing combined sewers and replace them with larger size combined sewers and tunnels to relieve street and basement flooding.