Water Security Agency


Wastewater effluents are the largest source of pollution by volume to surface water in Canada. Wastewater effluents may contain many pollutants and substances of concern including grit, debris, suspended solids, disease-causing pathogens, decaying organic wastes, nutrients and hundreds of chemicals.

Wastewater is a term typically used to describe liquid wastes from two types of sources. The first source, sanitary sewage, is generated from homes, businesses, institutions and industries. The second source, stormwater, is generated from rain or melting snow that drains off rooftops, lawns, parking lots, roads and other urban surfaces. Wastewater is collected by sewer systems and in most cases is treated before being released to the environment. (Source: Environment Canada)