Why does the Bay need a Phosphorus Management Plan?

To restore and maintain the bay to a healthy and sustainable condition for the long-term by reducing the risk of harmful algae blooms, while maintaining a sustainable fishery.

The main issue with the Bay of Quinte has always been the amount of excess phosphorus entering it from both rural and urban sources. Since the 1970s, there have been significant reductions in the amount of phosphorus entering the Bay from sewage treatment plants, agriculture, and stormwater. However, despite this progress, phosphorus levels and growth of undesirable algae blooms continues to be an ongoing issue in the Bay. As a result, the development of a Long-Term Phosphorous Management Strategy for the Bay of Quinte Area of Concern is one of the remaining key activities to be undertaken before delisting can be considered.

Recommended Phosphorus Management Actions

Recommended phosphorus reduction targets are based on modelling by the Department of Physical and Environmental Sciences University of Toronto, and input from academic and agency experts in the affected sectors (agricultural, sewage, and stormwater), on the feasibility of achieving these targets.

  • Reduce non-point phosphorus loading from agricultural land use by 20% (Note: based on current annual load estimates).
  • Reduce sewage treatment plant & industrial wastewater treatment plant based point source phosphorus loadings by an average of 60%, based on current Environmental Compliance Approval approved limits and no net increase in loadings into the future. This can be accomplished through maintaining a phosphorus effluent limit of 0.1 mg TP/L design objective for all sewage treatment plants and industrial dischargers in the Bay of Quinte watershed.
  • Reduce urban non-point stormwater loadings by 50%. The current loading estimate for stormwater inputs is 6.8 metric tons per year. This can be accomplished through adoption and implementation of existing recommended Pollution Prevention Control Plans, enhanced stormwater management controls, retrofits, and use of Low Impact Development technologies.