Humber Wastewater Treatment Plant

The Humber Wsatewater Treatment plant is a huge sewage processing facility at the mouth of the Humber river. At a size of 45 hectares it services roughly 680,000 people and has a capacity of 473,000 m³ of wastewater per day. Built in 1960, it's both Toronto's second largest facility and its most recent. At the time it was constructed, Montreal was still dumping sewage directly into the St. Lawrence and would continue doing so for more than 30 years.

The process that occurs inside the plant is fascinating. First, a preliminary treatment removes foreign material like rocks, sticks, garbage and hygiene products (dental floss, tampons, wipes, etc). Then, the primary treatment separates organic matter (poo) from the wastewater which is then treated separately for 10-20 days in large digesters. Following that, a secondary treatment is initiated where special microorganisms are made to "eat" pollutants over the course of several days before the water is clean (also removes phosphorous). Finally, the water is disinfected before being dumped into the lake. Currently a new odour treatment building is being constructed and some older buildings are being demolished. Below the surface, there is an extensive layout of tunnels, pipes and machinery that help operate the plant. These photos show just the tip of the iceberg…