Southwest Water Treatment Plant – Finished Water Storage and High Service Pump Station Expansion (CP3245)


Project Background: Prior to the initiation of this project an existing 3.0 MG (million gallon) welded steel ground storage tank was the only finished water storage tank at this 6.0 MGD (Million Gallon per Day) ground water treatment plant and it served as the only means to obtain chlorine contact time and to feed treated water to the high service pump station. Given these circumstances, the existing 3.0 MG steel ground storage tank has not been taken out of service for rehabilitation since it was commissioned approximately 20 years ago and is currently in need of a comprehensive rehabilitation.

Manchac Consulting Group, Inc. was retained by the City of Lake Charles to design a 2.0 MG pre-stressed concrete ground storage tank, an expansion to the facility’s high service pump station and all interconnecting piping to tie the new ground storage tank into the existing ground storage tank and high service pump station.

Through the construction of this new ground storage tank along with modifications to the existing high service pump station the existing ground storage tank will be able to be taken offline and rehabilitated. Modifications to the high service pump station include the addition of a fourth high service pump and installation of header piping and associated valves on the suction side of the pump station in order to allow for treated water to be drawn from either the existing 3.0 MG ground storage tank or the new 2.0 MG tank. Following completion of repairs to the existing tank, the high service pump station will allow the City of Lake Charles to operate both of their ground storage tanks in series, in parallel, or separately as may be required for future tank inspections and rehabilitation projects.

Manchac is responsible for the preliminary and final design, bidding and contracting, and construction management of this $3 Million project. This project’s construction completion is estimated for March 2018.