CTDOT Metro-North Rail Yard Maintenance of Way (MOW) Facility

New Haven, CT

AI provided design services for utilities, including water, sewer, electrical, and natural gas, for the Maintenance of Way (MOW) Facility located at the New Haven Rail Yard.

The proposed sewer system for the site consisted of a precast concrete duplex pump station with a force main discharge to the adjacent gravity system. The pump station system consists of an 8-ft.-diameter wet well, a 5-ft.-diameter valve pit, and approximately 1,000 lf of 2-in. SDR 21 PVC force main. AI provided hydraulic modeling with a peaking factor to determine the pump station sizing, float levels, and grinder pump requirements and to assess line velocities in the force main.

The existing water service to the site was provided by an 8-in. main that ties in with a 36-in. main. The existing building has a dedicated 8-in. fire service and a domestic supply service line. The existing sewer system consisted of a 6-in. gravity line discharge from the building to a duplex pneumatic sewage ejection system located at the northeast corner of the site. Power service to the site is provided via overhead three-phase power to a site utility pole. The overhead power connected to a transformer located next to the pole and enters the building beneath the slab. Natural gas service to the site was provided via a 2-in. service connected to a 4-in. high-pressure steel gas main.

The proposed water system connected to the existing 8-in. via hot taps, where the main runs through the established right-of-way. The proposed water improvements consisted of approximately 175 ft. of new 8-in. ductile iron pipe for the fire service connection, with two exterior hydrants, and approximately 175 ft. of 4-in. ductile iron domestic service line. Hydrant flow test results from two simultaneous tests were used to model the building demands in WaterCAD to check fire flow requirements. Water towers were modeled to calibrate the model to the existing static and flow conditions, and then hydrant flows were turned off and site demands activated to check operational and fire flow conditions for the site.

AI provided electrical design for the site and off-site storage areas. The electrical system connected to the existing yard power system and provides the main power feed to the transformer, building, and routing for site lighting, electric car charging stations, powered gates, and security measures. Electrical design for the off-site storage areas consisted of a step-down transformer and power station and power for lighting, gate, security needs, as well as several outdoor outlet locations.


  • Client: CTDOT
  • Duration: 2013 - 2018
  • Project Scope:
    • Pump station
    • Water modeling
    • Force main modeling
    • Utility design
    • Separate fire & domestic services