British Columbia experienced the largest improvements in treatment level between 1996 and 1999, as approximately 1 million people served by sewers were upgraded to secondary treatment. In Quebec, about 5.5 million people were served by some level of wastewater treatment in 1999, up from 4.5 million in 1994. Infrastructure improvements in the Prairie provinces, from secondary to tertiary treatment, were also noteworthy. In the Atlantic provinces, the levels of wastewater treatment have remained relatively unchanged since 1983. Nearly half of the population served by sewer collection systems released untreated wastewater directly into inland and coastal waters, relying on the dilution capability of the receiving water to reduce impacts on the aquatic ecosystem.
Municipal population refers only to municipal population served by a sewer system.
The slight decline in tertiary treatment in Ontario and Quebec between 1996 and 1999 likely results from the change in reported data verification procedures for the MUD survey starting in 1996. The MUD survey defines primary treatment as any form of mechanical sewage treatment, secondary treatment as biological sewage treatment or waste stabilisation ponds, and tertiary treatment as some form of sewage treatment providing a higher level of treatment than secondary treatment. Under the MUD survey definitions, mechanical screening could be considered as primary treatment. All rights reserved. You are on the SOE Infobase website, part of The Green Lane TM , Environment Canada's World Wide Web site.