The health of Roxton Lake is deteriorating rapidly. Despite numerous interventions by the municipality to restore the health of the water body (connecting residents living around the lake to the sewer system, setting up riparian buffers, agri-environmental practices), the lake has gone from eutrophic to hypereutrophic and episodes of cyanobacteria proliferation are increasing.
In response to this alarming situation, the municipality and CELR called on T² Environnement to conduct a feasibility study on the in-situ restoration of Roxton Lake. We estimated the proportion of orthophosphates and total phosphorus in the water column, but also the releasable phosphorus present in the sediments. We also modelled the phosphorus sources responsible for eutrophication of the lake and evaluated the costs associated with carrying out remediation methods for four selected in-situ remediation methods.
Several recommendations were offered to the municipality and CELR to control phosphorus inputs to the lake. Finally, T² Environnement negotiated with MELCC to integrate their requirements into the study and make it easier for the restoration project to be accepted.