Trumbull's OSIS Augmentation and Relief Sewer project update
OARS Phase 2 is a Combined Sewer Overflow Project located in Columbus, Ohio. The purpose of the project is to eliminate the direct discharge of over a billion gallons annually of raw sewage into the Scioto River. The project involves constructing three deep shafts ranging in diameter from 15' to 33'. These shafts connect to the existing sewer system via a Tangential Inlet and proposed Relief Structure. The base of the deep shafts are connected to the proposed 20' diameter relief sewer via a 150' long, 18' diameter Deaeration Chamber and a 50' Adit section.
Major components of construction include the support of soft ground during excavation via secant piles, the elimination of ground water utilizing rock grouting, the drilling/shooting/excavation of 18,000 CY of rock, excavation support, 1,200 LF of microtunnel, and the forming and pouring of over 7,000 CY of Inlet Concrete.
Currently, excavation at all 3 shafts is nearing completion, and Trumbull is preparing to place the final shaft concrete liner. In addition, the Tangential Inlets are progressing as well as the relief structures. This project is expected to be completed in June of 2015.