Chilliwack Waste Water Treatment Plant Biological Treatment System Expansion

The Chilliwack WWTP Biological Treatment System Expansion Phase 1 Project utilized a Design-Build contract format to provide for the design, construction, and commissioning of the overall expansion project.

NAC, together with our project partner and engineer, OPUS DaytonKnight, completed the project scope of work which centered on the following key elements:

• Re-direction of the trickling filter (TF) effluent from the existing solids contact tank to a new bioreactor
• Provision of Train #1 of a new bioreactor, including an aeration system consisting of a minimum of two aeration blowers and fine bubble aeration diffusers mounted onto aeration grids that can be easily removed for maintenance without taking the bioreactor out of service
• Installation of a new flow splitter box between the bioreactor and the secondary clarifiers, including construction of new pipelines and modifications to existing pipelines in and out of the new flow splitter box
• Construction of a new Secondary Clarifier #3 and ancillary equipment and systems similar in all respects to existing Secondary Clarifier #2, including construction of new pipelines and modifications to existing pipelines in and out of the new Secondary Clarifier #3
• Electrical, instrumentation and control system upgrades to provide power and automate the service on the bioreactor and aeration system, blowers, and the new Secondary Clarifier #3
• Modification of the existing RAS/WAS piping systems to include RAS/WAS from Second¬ary Clarifier #3, and modification to RAS discharge piping at the trickling filter effluent channel
• Relocation of scum pump station and modifications to existing piping systems to include the provision for scum discharge from Clarifier #3