Conveyance and Storage Tunnel in Hartford, Connecticut
The South Hartford Conveyance and Storage Tunnel (SHCST) is a major component of the Hartford Metropolitan District’s Clean Water Project (CWP). This tunnel is intended to capture and store Combined Sewer Overflows (CSO) from the southern portion of Hartford, CT and Sanitary Sewer Overflows (SSO) from West Hartford and Newington, CT. The project is estimated to cost approximately $500 MM and will be constructed in multiple construction contracts. The project components include a deep rock tunnel 6.6 km in length with a 7.6-m excavated diameter, several kilometers of consolidation sewers, multiple hydraulic drop shafts with deaeration chambers and a 100 MLD tunnel dewatering pump station. The TBM-bored tunnel will be excavated in shale, siltstone and basalt through several fault zones. AECOM is currently performing the final design for this project. This paper discusses the major aspects of the final design of the SHCST.