Municipal wastewater treatment indicator: data sources and methods, chapter 2

2. Description and rationale for the Municipal Wastewater Treatment Indicator

2.1 Description

The municipal wastewater treatment indicator measures the level of wastewater treatment provided to the Canadian population. Higher levels of wastewater treatment reduce the risk of pollutants from raw wastewater reaching the environment, where they pose risks to human and environmental health. This indicator is not a measure of municipalities' compliance with municipal, provincial or federal wastewater regulations or treatment standards.

2.2 Rationale

Municipal wastewater is one of the largest sources of pollution, by volume, to surface water in Canada.^{Footnote [1]} Treated wastewater may contain grit, debris, disease-causing bacteria, biological wastes, nutrients and chemicals with the potential to damage human and environmental health. The higher the level of treatment provided by a wastewater management system, the cleaner the effluent and the less the impact on the environment.