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.
These events are common during the summer months.
Long-term nitrate trends in PEI streams are available for the late 1960's to the present. Nitrate data is available in the Surface Water Quality Database. The pathway of most of the nitrate in P.E.I. streams is from groundwater.
A map of groundwater concentrations is available or you can query a database for your area. A graph of the long-term nitrate trend in groundwater is also available.
What is being done about the issue?
The 2008 Report of the Commission on Nitrates in Groundwater describes the nitrate problem in PEI and recommends actions to deal with the issue. Nearly all of the recommendations involve changing land use practices to reduce nitrate loss. The needed changes can be achieved—but this will require the cooperation and support of all Islanders.
Some of the ways Government is helping to find solutions include:
- funding community watershed groups who work to improve local water quality;
- nutrient planning on a watershed basis; and
- providing financial incentives to the farming community to help make nutrient reduction plans feasible, e.g. Alternative Land Use Services Program