The City of Corner Brook, with its population of approximately 20,000, is a vital community that provides an important link to the west coast of Newfoundland. The city originally tendered a traditional Design/Bid/Build construction contract for a new 30 MLD green field water treatment plant. However, when that tender came in well over budget, the project was cancelled. The City then decided to follow a Design/Build process with the goal of reducing overall capital costs.
Our firm was retained by Pomerleau to lead the development of an innovative design concept that would compete against two other Design/Build teams. The Pomerleau/JLR team was eventually selected to implement a concept that cost millions of dollars less than the original Design/Bid/Build project. Upon award of the project, we continued to work with the contractors, City, and agents in the development of additional design details, including 100% completion drawings and technical specifications. Pilot testing of the treatment process was undertaken, then construction of the new plant was initiated and completed within two years.
The treatment process is a three-train system that includes dissolved air floatation, rapid sand/anthracite filtration, and ultraviolet disinfection. Chemical storage/feed systems include coagulant, polymer, soda ash, corrosion inhibitor, and chlorine gas for secondary disinfection. Water is stored on site in two large above-grade glass-fused-to-steel circular/domed tanks. The overall scheme relies largely on gravity to convey water through the treatment system and into the city’s water distribution network. Only one set of relatively low-head pumps is needed to convey treated water from a below grade filtered water tank into the on-site storage tanks, and these same pumps are also used for filter backwashing. The plant includes a loading dock for chemicals, offices for staff, a full laboratory for water testing, a service garage, and other facilities to support operations and maintenance staff and the treatment processes. The entire plant was designed to fit within an existing excavated footprint established for the previously cancelled tendered project.