Nitrate is an essential nutrient for life, however too much nitrate can cause environmental and human health problems. Both the U.S. and Canada have established the maximum concentration level (MCL) for nitrate at 10 milligrams per liter.

This tool tracks nitrate concentrations in raw water in major rivers near our partner communities using USGS and EPA water quality data. Communities’ watersheds are shaded yellow. The dots on the map are water monitoring locations, with black dots representing continuous monitoring locations funded by the Great Lakes Restoration Initiative in the US.

Click on orange watersheds to see graphs of available nitrate data.