Responsible phosphorus limits at the Duffin Creek Plant

Session: 55. - Solutions for Lake Ontario: Addressing the Human Footprint on Regional Water Quality

Barry Laverick, The Regional Municipality of Durham, [email protected]

Abstract

The Regional Municipality of Durham and The Regional Municipality of York (Regions) own and operate the Duffin Creek Water Pollution Control Plant (Duffin Creek Plant). Due to a recent expansion and upgrade, the Duffin Creek Plant is now the second largest wastewater treatment plant on Lake Ontario with some of the most strict effluent phosphorus concentration limits of any Policy 1 wastewater treatment plant. In addition, a comprehensive nearshore water quality monitoring program has been carried out in the vicinity of the Plant for a decade.

In 2010 the Regions began an environmental assessment (EA) to investigate the Duffin Creek Plant outfall. However, due to the resurgence of Cladophora in the Great Lakes and more specifically in the nearshore adjacent to the Duffin Creek Plant, a re-examination of recent choices regarding appropriate treatment was included as part of the EA scope. In addition, a recent Minister’s Order for additional EA information requested a review of both optimization and tertiary treatment options for the Duffin Creek Plant.

This presentation will discuss the water quality results of the nearshore program, the findings of our EA-related investigations, potential phosphorus limits in the context of impending Lake Erie and Lake Ontario phosphorus limits and local Cladophora research.

1. Keyword
regulations

2. Keyword
Cladophora

3. Keyword
phosphorus

4. Additional Keyword
wastewater treatment