South Hartford Conveyance and Storage Tunnel


Construction Cost: $500 Million

Key Facts:

  • Traffic Study
  • Maintenance & Protection of Traffic Plans
  • Structural Inspection & Evaluation of Span Poles

The South Hartford Conveyance and Storage Tunnel (SHCST) is a four-mile long deep rock tunnel constructed to convey and temporarily store wastewater from portions of Hartford and West Hartford during storm events. The tunnel diameter is 18 feet and is located at a depth of 200 feet. 

GM2 provided traffic design services in this multiphase project from the preliminary design phase to providing engineering services during the construction.

During the preliminary design phase, GM2 prepared a traffic study report with assessment of impacts from tunnel muck hauling and made recommendations to minimize the impact of the haul trucks and workers’ vehicles on the adjacent street system for multiple possible haul routes. Conceptual traffic control plans were prepared to address site access and staging operations for the proposed work zone locations.

During the final design phase, GM2 prepared plans, specifications, and estimates for maintenance and protection of vehicular and pedestrian traffic during construction. Extensive coordination was required with the City of Hartford due to the location of the work zones in busy urban areas and residential areas as well. GM2 also performed a structural analysis of the proposed traffic signal span at a site where the span and signal heads had to be modified to accommodate the work zone. A condition inspection, assessment and evaluation of three traffic signal span poles associated with this modification was performed as well.

During the construction phase, GM2 provided traffic inspection services to verify the implementation of the traffic control plans and made recommendations for field adjustments.