Wastewater Treatment

Wastewater is any water that is used in a home, school or business and that leaves through a drain after it is used. This could include water which was discharged from a sink, shower, or washing machine. Given the nature of these sources of wastewater, it is not surprising that wastewater's composition is mostly water. In fact, on a volume basis, wastewater is about 99.9% water. The remaining 0.1% by volume is solid materials. (Click here for more information about wastewater collection in York Region.)

The average person uses roughly 300 litres of water per day. This means that a typical home with 3 to 4 occupants, generates about 1,000 litres of wastewater a day. That's equivalent of 5 bathtubs!

The treatment process uses physical, biological and chemical means to remove a number of contaminants and permit safe discharge of water back into our rivers and lakes. The accumulated solids removed through the treatment process are known as biosolids or sludge.

The first, or primary stage of treatment removes debris and larger particles by screening, de-gritting and/or settling. Secondary treatment consists of biological reactions that break down organic contaminants. In some locations a third, or tertiary, treatment step is required to achieve even higher levels of contaminant reduction. Finally, most locations require disinfection prior to discharge. Chlorine is commonly used for disinfection but is likely to be replaced with ultra-violet radiation in the coming years.

The following map illustrates wastewater collection and servicing in York Region.

Click here to access York Explorer mapping for more details on serviced areas.