City of Columbus Lower Olentangy Tunnel

CSS is currently performing scheduling services for the Lower Olentangy Tunnel project. The scope of this project is to improve the water quality and reduce the risk of exposure of humans to waterborne pollutants by reducing overflows from the sewer system into creeks and rivers during flooding. The tunnel will connect into the upstream end of the previously Granite constructed OSIS Augmentation Relief Sewer (OARS) at Vine Street. Surge controls, system ventilation control, and odor controls will be added to coordinate with the OARS facilities. The upstream end of the tunnel will be located north of Lane Avenue and will provide hydraulic relief to the three existing sewers that are located near each other. The construction of the main Lower Olentangy Tunnel will consist of 17,000 feet of 144-inch hand-mined diameter tunnel and will be mined with a tunnel boring machine and constructed of precast concrete segments.

Our team is responsible for the development and maintenance of the baseline schedule and coordination on behalf of the contractor. Utilizing Primavera P6, CSS worked very closely with the Contractor and the Sewer District to develop the schedule and incorporate critical activities of milestones. CSS conducts on-site monthly reviews of the progress to determine actual progress is consistent with the schedule plan.  Monthly reports are being provided for the contractor and the Sewer District to reflect progress, earned value and critical path analysis. Monthly narratives are also reviewed by the Team to make sure the milestones are not jeopardized.

Location: Columbus, Ohio
Cost: $267 million
Services: CPM Scheduling
Owner: City of Columbus