Chilliwack WWTP Inlet Works and Emergency Repair Works to Primary Clarifiers

Owner: City of Chilliwack
Project Completion: Dec 2021

Tritech’s scope of work for this project included:

• Construction of a new Inlet Works Building to house the equipment required for fine screening, screenings washing/compacting, grit and septage separation and transfer pumping
• Efficient and high-performance screening units with screenings processing
• A high-performance induced vortex grit removal system with grit processing
• Septage system
• Pump station supply and installation
• Construction of a pipeline to convey screened / de-gritted wastewater from the Inlet Works Facility to the existing primary clarifiers
• Associated geotechnical, civil, structural, architectural, mechanical, electrical & instrumentation

Emergency Repair Works to Primary Clarifiers:
During the upgrade works, a trough collapsed in Primary Tank #1 requiring an emergency repair (unrelated to Tritech’s work). The City retained Tritech to complete emergency repairs as follows:

Phase 1 The Isolation Process:
Prior to completing the proposed repair work, Tritech was required to obtain WCB approval for their method of isolating the discharge channel with an engineered bulkhead gate and sandbags.

Phase 1 work included the following:

• Obtain WCB approval for the proposed isolation method
• Conduct sampling of the existing concrete to determine the extent of the concrete repairs
• Demolition of the existing trough

Phase 2 The Concrete Repair:
Phase 2 included the concrete repair, fabrication, and installation of the channels and troughs in primary tanks #1, #2 and #3. To complete the proposed repair work, Tritech executed the WCB approved method as submitted on Phase 1.