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 surfaces¹.

Wastewater according to [EN752:2017]consists of any combination of water discharged from households, industrial and commercial enterprises, storm runoff and any extraneous flows.

According to CAN/CSA-Z24511-10, “Wastewater is always generated when water is used or consumed. Accordingly, sources of wastewater can be residential, industrial, commercial or institutional. Collected stormwater or (melted) snow can also be considered as wastewater”.

¹_{Wastewater Management - Canada.ca. Retrieved from https://www.canada.ca/en/environment-climate-change/services/wastewater/management.html}