Nitrate in Surface Water

Nitrate is a form of nitrogen. It can readily dissolve in water and can travel easily through soil to the water table.  As a result, nitrate is common in our groundwater, ponds, streams, and estuaries. 
Human activity is responsible for over 90% of the nitrates in many Island waterways. The main source of nitrate contamination is fertilizers and manures applied to agricultural lands.  Wastewater from sewage treatment (including municipal wastewater treatment and private septic systems), food processing, and other industrial activities are other nitrate sources
Nitrates in our streams, ponds, and estuaries cause an increased growth of plants and algae, including sea lettuce.  This process is called eutrophication.  In PEI, the common symptoms of eutrophication are:

  • ponds and waterways choked with plants or algae growth (e.g., sea lettuce);
  • discoloured water due to plankton (microscopic algae) blooms; and
  • low dissolved oxygen levels and anoxic events. 

Information on nitrate is available: 

Published date: 
August 9, 2023