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News Release
News Date: September 10, 2015

Mayor Coleman, Councilmember Klein Celebrate Tunnel Project Milestone

Mayor Michael B. Coleman, City Councilmember Zachary M. Klein and Department of Public Utilities Director Greg Davies joined other community leaders in the Arena District, where tunneling for the largest capital project in Columbus history has concluded. The two-phase OSIS Augmentation Relief Sewer (OARS) project, totaling just under $371 million, will dramatically reduce combined sewer overflows in downtown Columbus.

Excavating the 20-foot diameter tunnel began at the Jackson Pike Wastewater Treatment Plant in 2010 and extended north nearly 4.5 miles, going as deep as 190 feet. When functional by late summer 2017, the new sewer will eliminate more than one billion gallons of overflows annually from the existing Olentangy-Scioto Interceptor Sewer (OSIS) by storing and transporting that wastewater to treatment facilities, rather than having it overflow into the Scioto River during periods of heavy rain.

“When our sewers overflow, it’s bad for the river and bad for our city,” said Mayor Coleman. “This project will greatly reduce those overflows, making our river cleaner and improving the quality of life around it.”

Now that the tunneling work is complete, the next steps include removing the 95-ton cutterhead and the rest of the 540-foot long Tunnel Boring Machine; putting finishing touches on the OARS tunnel itself and connecting it to the existing OSIS trunk sewer; and constructing the pump station at Jackson Pike that will lift the flow of the new tunnel into the facility for treatment.

“We have done and will continue to do everything we can to keep the costs of this project as low as possible,” said Councilmember Klein, chair of the Public Utilities Committee. “This project also qualifies for low-interest loans through the Ohio Environmental Protection Agency that will, over the life of the loan, save our ratepayers millions of dollars as compared to financing through higher interest rate bonds.”

More information on OARS, or visit: (or and click on Projects.)