The federal government became involved in water quality monitoring in 1934, emphasizing water used by municipalities and industry. The growing awareness of environmental issues among Canadians in the 1960s led to a national water quality network being established to assess the impact of human activities on rivers and lakes, not only in agricultural areas but also throughout the country. This database provided a comprehensive overview of the quality of Canadian surface waters and was used with national water quality guidelines to establish water quality objectives for lakes and rivers. The federal government monitors the quality of surface water under the Canada Water Act and the Canadian Environmental Protection Act through Environment Canada. In some regions, provincial governments have taken over monitoring the water quality of inland rivers and lakes in areas in which they have an interest.
National coverage is therefore incomplete and inconsistent.
At present, no single agency operates a general, nationally integrated monitoring program for water quality in Canada. The federal government generally does not undertake programs to routinely assess the quality of groundwater, mainly because groundwater is legislated as a provincial resource. In such cases, groundwater monitoring is undertaken at a specific location by the regional offices of Environment Canada in collaboration with provincial government agencies. Natural Resources Canada's Geological Survey of Canada is involved in groundwater quantity research and monitoring in several regions of Canada.