Metro Vancouver is serviced by five wastewater treatment plants. The Annacis Island wastewater treatment plant is among the largest, treating about 175 billion liters of wastewater each year.
History
The plant is designed both as a primary and secondary treatment plant. The primary treatment utilizes mechanical processes to remove surface and settled solids, or about half of the solids in the wastewater. The remaining solids and dissolved pollutants are removed during secondary treatment, which uses aerobic bacteria to remove dissolved organic matter. Annacis Island treats wastewater for over 1 million residents across 21 municipalities, one Electoral Area, and one Treaty First Nation.
Problem
Vancouver is expected to grow to a total population of 3.4 million by 2041—a growth of about 1 million residents. The increased population will weigh heavily on the city’s existing infrastructure, requiring upgrades or new developments to fill the gap. A key initiative to help meet the region’s wastewater treatment needs is the expansion of the Annacis Island wastewater treatment facility.
Solution
The expansion to the Annacis wastewater treatment facility will take place over several years and comprises over 20 projects that will ultimately improve the facility’s capacity. These currently planned expansion projects are being conducted in phases and include new trickling filters, secondary clarifiers, and a co-generation facility that will improve the energy generation from the recycled energy captured on site. The expansion will also feature a new outfall pipe. Overall, all the expansion project together will increase the volume of treated wastewater, improve the generation of on-site green energy, and manage odor. Eventually, the facility will also be able to quickly recover and resume operating even shortly after a major earthquake.
Concrete protection is an essential element in extending the lifespan of many critical concrete structures that make up wastewater treatment facilities. Concrete protection liners (CPL) help prevent corrosive compounds and gases from damaging the structures. Since the early 1990s, Metro Vancouver has utilized AGRU-SURE GRIP, a high-density polyethylene (HDPE) CPL, on at-risk concrete structures exposed to and in contact with wastewater. As part of the expansion effort at Annacis, the primary influent channel, pre-aeration tanks, and primary effluent channels are being expanded. These new constructions will use AGRU-Ultra Grip to line the walls and ceilings. AGRU-Ultra Grip is a new version of AGRU-SURE GRIP which utilizes an enhanced anchoring system design.
