TORONTO – An overwhelmed sewage system during Toronto’s downpour earlier this week resulted in more than 1,300 megalitres of partially treated wastewater spilling into Lake Ontario.
That’s enough sewage to fill 500 Olympic-sized (50-metre) swimming pools.
Operators were forced to bypass the secondary process of sewage treatment to keep up with the amount of sewage being processed. Primary treatment includes phosphorus removal, grit removal, and full disinfection in order to meet strict regulatory requirements. Despite that, many beaches in the Toronto area were closed for swimming for at least 48 hours due to high levels of bacteria, notably E. coli.
On July 16, a line of thunderstorms dumped a month’s worth of rain on the city—almost 100 millimetres—causing widespread flooding. The Insurance Bureau of Canada estimates $1 billion worth of damage was caused.
