What Causes Pollution at Torontos Beaches?
Urbanization is one of the main contributors to water pollution. Within Toronto’s large urban centre, the sanitary sewer system is designed to collect and treat human waste, while the storm sewer system is designed to collect rainwater. However, due to development, in a storm, rainwater washes material and debris from roofs, gutters, streets, lawns, parking lots and sidewalks into the storm sewer system. It trickles down in tiny streams and through drain pipes finally ending up in catch basins (Figure 3). This causes untreated storm water carrying animal feces, pesticides, used motor oil, etc. to flow untreated into Toronto’s waterways. Pollutants in stormwater contribute to poor water clarity, elevated concentrations of metals and organic contaminants, increased water temperature, and the accumulation of trash. When combined sewers overload the treatment plants, high concentrations of nutrients and bacteria can cause beaches to be frequently unfit for swimming.
