Water Hammer Hazard Mitigation Grant Program

Trigon is a major sub-consultant (with 23% of the project) for engineering and design efforts to mitigate water hammer events/effects in the New Orleans East Bank water distribution system by upgrading facilities at the Sewerage and Water Board of New Orleans’ (S&WB) Carrollton Water Treatment Plant (WTP) complex as well as power supply infrastructure at the S&WB’s power plant, co-located with the WTP.

Primary improvements resulting from this project include modifications to finished water pump stations, plant piping/valves/meters, a new building to house Variable Frequency Drives (VFDs) and other electrical and controls equipment, power supply modifications, two (2) new elevated storage tanks, and one (1) remote-site bladder tank installation.

Trigon staff supported the identification of alternatives to mitigate issues through the review and verification of an existing hydraulic model for the water distribution system. The model was updated to current standards, and additional details were added (including detailed piping configurations within the WTP complex) to increase the model’s predictive accuracy. The model was then used as the basis for a surge analysis from which various alternative options were considered for reducing the likelihood of water hammer events occurring that could damage pumping and piping facilities. The improvements, estimated at approximately $70M, were packaged into three (3) construction bid packages. Trigon led the design efforts for two (2) of the packages and also provided design support on the third construction package.

Design is complete for all three (3) construction packages. Construction is complete for one (1) package that includes the installation of two (2) new water towers. Construction is ongoing for the second package which includes the Claiborne Pump Station and Offsite improvements. The final package, which is associated with the Panola Pump Station, is expected to be completed in 2024.