Water Quality
Improving water quality involves controlling point source and nonpoint source pollution, whether from bacteriological or chemical contamination, the presence of factors compromising the environment's physical integrity, contaminated sites or the introduction of new contaminants.
With the goal of reducing water pollution, four major orientations have been established to guide the work of the governments of Canada and Quebec in order to shed light on the point sources of contamination of the St. Lawrence:
- Reduce agricultural sources of nonpoint source pollution
- Improve management tools for contaminated sediment
- Assess the presence of toxic substances and their effects on the ecosystem
- Document fluvial inputs to the St. Lawrence estuary
Each of the orientations is accompanied by objectives and specific projects.
![[Translate to English:] Le fleuve Saint-Laurent vu d'une plage](/fileadmin/_processed_/7/d/csm_plan-saint-laurent-qualite-eau_2c072b3cfe.jpg)
Projects to Improve Water Quality
Point sources of water contamination in the St. Lawrence have been identified and fairly well described. On the other hand, less is currently known about nonpoint source pollution and its effects on human health. Examples of nonpoint source pollution include nutrients from agricultural runoff and atmospheric inputs as well as new contaminants from wastewater discharge or the resuspension of contaminated sediment.
To complement the work being undertaken by governments, non-governmental organizations and non-profit organizations are encouraged to take action by presenting a project supported by their community under the Community Interaction Program.
1st Orientation: Reduce agricultural sources of nonpoint source pollution
Point sources of contamination in the waters of the St. Lawrence, such as municipal and industrial effluents, are fairly well characterized and localized. On the other hand, nutrients and various contaminants from the agricultural areas cause nonpoint source pollution, which is at the origin of eutrophication and contamination problems in the waters of the St. Lawrence. Research of new solutions to reduce the sources and impacts of nonpoint pollution is necessary.
2nd Orientation: Improve management tools for contaminated sediment
Contaminated sediments collected at the bottom of the St. Lawrence waters, distant or recent legacy from industrial activities, represent a risk for human health and ecosystems when they are resuspended. Using new scientific knowledge, the governments must update regularly their contaminated sediments management tools, in order to reduce risks associated with contamination.
3rd Orientation: Assess the presence of toxic substances and their effects on the ecosystem
The growing presence of emerging contaminants related to wastewater discharge as well as urban and agricultural streaming waters still has unknown effects on the environment and on human health. The future of these toxic substances and of their degradation products in the River is still unknown and the complexity of the interactions between these substances and the bacteriological load associated with these rejections raises several questions regarding the risks of toxicity in aquatic ecosystems.
4th Orientation: Document fluvial inputs to the St. Lawrence estuary
Increased fluvial inputs of organic carbon and nutrients associated with human activities can lead to eutrophication in estuaries and coastal areas. This eutrophication can result in the proliferation of toxic or harmful algae and the development of hypoxic and acidified areas that threaten the health of the St. Lawrence River. The participants have resolved to evaluate and gain a better understanding of the contribution of fluvial inputs on hypoxia, acidification, and the appearance of toxic algae in the estuary.