It would be nice to know what the current phosphorous loading is.
Here in Barrie, one of the pollutants entering the lake is harmful ASBESTOS fibres from up to 100 streets paved with ASBESTOS-Asphalt mix. Asbestos has the ability of irreparibly harming the fish in Lake Simcoe.
Then there’s Sodium Chloride aka SALT. This too needs to be seriously controlled.
Also, given the explosive growth in urbanization along the shores of Lake Simcoe from Orillia down and around to Keswick, would it not make sense to corral all that new surface runoff into holding ponds and clean out pollutants such as phosphorus and other pollutants? I think so.