The Canadian Environmental Sustainability Indicators CESI program provides data and information to track Canada's performance on key environmental sustainability issues. The Phosphorus and Nitrogen Levels in the St. Lawrence River indicator reports on the status of total phosphorus and total nitrogen concentrations along the St. Lawrence River for the 2010 to 2012 period. The indicator rates nitrogen and phosphorus status based on whether total phosphorus and total nitrogen concentrations exceed Quebec's total phosphorus water quality guideline for the protection of aquatic life, and its total nitrogen water quality guideline for the protection of aquatic life. When phosphorus and nitrogen concentrations exceed their respective water quality guidelines, this exceedance indicates that phosphorus and nitrogen pose a greater risk to the health of the St. Lawrence River aquatic ecosystem. Information is provided to Canadians in a number of formats including: static and interactive maps, charts and graphs, HTML and CSV data tables and downloadable reports. See supplementary documentation for data sources and details on how those data were collected and how the indicator was calculated.