The average age of Alberta's wastewater treatment facilities rose steadily from 12.1 years in 1983 to 19.8 years in 2004. Investments were low during these years, but have since been much more robust and sufficient to lower the average age to 17.7 years in 2007.
As a percentage of estimated useful life, Alberta peaked in 2004 at 70% but has since dropped considerably to 63% in 2007, the same as the national rate.