South Hartford Conveyance and Storage Tunnel: Consolidation Conduits (Contract No. 5)

Arlington, New Britain, and Newington Consolidation Conduits

CRS Contractors, Inc. performed the construction of the Arlington, New Britain, and Newington Consolidation Conduits, key components of the South Hartford Conveyance and Storage Tunnel project for the Metropolitan District Commission (MDC) in Hartford, Connecticut. The work formed part of MDC’s Clean Water Project and Long-Term Combined Sewer Overflow Control Plan. All three conduits were constructed using microtunneling to install reinforced concrete and fiberglass reinforced polymer mortar jacking pipes beneath urban infrastructure with minimal surface disruption. The microtunneling operations traversed glaciolacustrine deposits consisting of alternating layers of sand, silt, and clay—commonly referred to as Connecticut Valley Varved Clay—requiring precise control of face pressure and alignment. For the Arlington Consolidation Conduit, CRS installed approximately 910 linear feet of 42-inch diameter reinforced concrete jacking pipe using a Herrenknecht AVN1000XC microtunneling machine. The New Britain Conduit consisted of 1,135 linear feet of 54-inch diameter linear feet installed with a Herrenknecht AVN1200TB and 1,280 linear feet of 30-inch diameter centrifugally cast fiberglass reinforced polymer mortar (HOBAS) pipe installed by pilotube microtunneling method using a Akkerman Guided Boring Machine. The Newington Conduit comprised 1,781 linear feet of 42-inch diameter RCJP, also installed by microtunneling with the AVN1000XC. With this work, CRS Contractors demonstrated its capability to execute complex, multi-drive microtunneling operations in challenging geotechnical conditions while maintaining strict tolerances and environmental protections. The project underscored the firm’s long-standing expertise in trenchless technology and public infrastructure construction.