What is Phosphorus?
Phosphorus is an essential nutrient that both plants and animals need to survive. It is found in human and animal waste as well as fertilizers. Phosphorus is often the “limiting nutrient” in freshwater environments, which means that it is the nutrient controlling aquatic plant growth. When phosphorus is at low concentrations, algae growth is kept in check but if phosphorus suddenly becomes readily available, algae growth can skyrocket, forming a bloom.
Sources of Phosphorus
Phosphorus has two general means of introduction to the environment: point sources and non-point sources. As the name suggests, point sources are a single, identifiable source, for example, effluent discharging from the pipe of an industrial or sewage treatment plant. Whereas non-point sources of phosphorus result from many diffuse sources that occur over a wide area, for example, overland runoff of manure or fertilizer.
The main sources of phosphorus in the Sydenham watershed are non-point sources, this reflects the land use in the region which is 85% agricultural. If excess nutrients from fertilizers or manure are washed off the land in a rainstorm or spring snow melt, they are carried into local watercourses and can cause algae to bloom.
Reducing the Phosphorus Load in the Sydenham
The Sydenham watershed is in the Lake Erie basin and is a contributor to its phosphorus load and the algal blooms that occur in the lake each summer. But the high concentrations of phosphorus in the Sydenham are not only an issue downstream, excess nutrients also degrade the local water quality and are one of the biggest threats to aquatic life in the Sydenham watershed, which includes species of global conservation concern.
To help reduce the impact of this nutrient on the health of the watershed and the Lake Erie basin, the St. Clair Region Conservation Authority is coordinating the development of a Phosphorus Management Plan for the Sydenham watershed. With financial support from Environment and Climate Change Canada and the Ministry of Environment, Parks and Conservation, the SCRCA is working with local stakeholders and rights holders to identify sources of phosphorus, determine the best-value solutions, and implement an outreach strategy to work together with the community.
How Can We Reduce Phosphorus Loading?
There are lots of actions landowners and community members can take to help retain nutrients on the landscape, such as:
- Phosphorus can build up in the soil, so if you use fertilizers or other nutrient sources, ensure that you are only using the amount needed by the plants and are not over-applying. Also consider when you are applying these nutrients – do not apply to frozen ground or before a heavy rain as it will be washed away.
- Reduce the amount of pavement and other hard surfaces on your property since they do not allow rainwater to soak into the ground and instead cause more runoff that carries phosphorus and other pollutants to lakes and rivers via storm drains and ditches.
- To reduce and slow down runoff, consider planting a rain garden, using rain barrels, or establishing vegetation along watercourses.
- If you have a septic system, ensure it is receiving regular maintenance and doesn’t become clogged. Septic tanks need to be cleaned out when solids fill a third of the tank. Ensure the leaching bed is functioning properly and do not pave or drive over it. Divert excess water away from the leaching bed and ensure downspouts are not connected to the septic tank.
- Support the conservation and restoration of natural areas like forests and wetlands.
- If you are a farmer or rural landowner in the region, find out about other beneficial practices and grant opportunities available to you by contacting the SCRCA (or your local conservation authority)
Learn more about how you can help reduce phosphorus loading and protect the Sydenham by visiting our Get Involved page.