If anything positive can be said about the cholera and typhus epidemics that swept Metro Toronto in the mid 1800s, it is that the threat of a fatal disease stopped residents from dumping their outhouse pails on to the street. Once society understood the connection between diseases and human waste, the need for a sewage system was recognized. At first untreated sewage was dumped into the nearest body of water where it was supposed to disperse naturally. Unfortunately, this did not always happen. Instead, much of this untreated sewage ended up washing on to our beaches to the dismay of tourists and residents. It also contaminated local bays from which drinking water was drawn. Today, the sewage treatment process is far more extensive and efficient. Sewage undergoes two treatment processes that remove solids, chemicals and other undesirables before the water is released into the natural water supply.
Ashbriges Bay Sewage Treatment Plant is Toronto’s first and largest. When it was built in 1910, it treated 150,000 cubic metres of wastewater a day. By 1953, it was one of 18 sewage treatment plants scattered across the 13 municipalities that became Metropolitan Toronto. Most of these plants were overloaded and ill-equipped to serve their areas so in 1954, the new Metro government, decided most was replace them with larger, more efficient ones. The three other sewage treatment plants that are operated today are the North Toronto, the Highland Creek and the Humber. The North Toronto plant is likely to be closed in the next few years or used only to treat storm water.