Grant: Engage Plus Grants Program

The completed ENGAGE funded collaboration between I. Spooner and Halifax Water (HW) focused on thedevelopment of methods of measuring the impact of watershed development and environmental change onwater quality in surface water reservoirs in Halifax Regional Municipality (HRM). HW is an autonomous,self-financed water utility, and is responsible for 17 water supply reservoirs that service over 400,000residents. The Engage study provided significant insight on the effect of catchment land use on 3 reservoirs,the effect of sediment-water interface redox on the deposition of metals, and changes in the character oforganic deposition over time. In particular the research identified spatial variability of metal concentrations thatmay be a result of water depth and subsequently redox conditions. Metals and dissolved organics represent asignificant treatment cost to HW and the Engage funded research was able to provide valuable informationabout the mechanisms that increase and decrease these concentrations in the water column. The success of thisapproach in the three lakes studied and the recognition that metal concentrations can vary significantly nearwater intakes indicates that the research should be expanded to include other important HW water supplyreservoirs and provide additional spatial resolution in Bennery Lake, Lake Major, and Pockwock Lake.Focusing on metal deposition both at water intakes and in the deeper basins of reservoirs is a novel approachthat will provide historical profiles of metal variability and organic matter sources over a large area and refinethe interpretation of the processes that control metal variability and organic matter source for all lakes in thestudy. Continued development of expertise in the rapid assessment of lake vulnerability to development andenvironmental change will position HW to more effectively manage lakes and reservoirs and to become aninternational leader in watershed management.