In December, I was honoured to welcome mayors and municipal leaders from across Canada and the U.S. to Toronto for the mid-year meeting of the Great Lakes and St. Lawrence Cities Initiative (GLSCI). The GLSCI is a binational coalition of 131 mayors from Ontario, Quebec, and the eight American Great Lakes states who advocate for the protection and restoration of the Great Lakes and St. Lawrence River. The Great Lakes are a critical and irreplaceable resource, and I was inspired by the GLSCI's commitment to their continued protection.
The Great Lakes and St. Lawrence River contain approximately 20% of the world's freshwater supply and provide drinking water for over 40 million people. The impacts of the Lakes are so broad that it is necessary to collaborate across national and regional boundaries to ensure their protection. The GLSCI's notable initiatives include efforts to ban the production and distribution of products containing microbeads, mitigate the impacts of climate change and greenhouse gas emissions, incorporate innovative technology in conservation strategies, and manage invasive species such as zebra mussels and Asian carp.
In Toronto, we are undertaking various initiatives of our own to protect the Great Lakes water system. For example, a 25-year, multibillion dollar infrastructure project is currently underway to reduce combined sewer overflow (CSO) in the Don River as a part of the City's Wet Weather Flow Master Plan. Most combined sewers were constructed as long as a century ago, and utilize one pipe to carry both sewage and stormwater. Usually this combined water is diverted to wastewater treatment plants, however, during periods of intense rainfall, the volume of water may exceed the system's capacity. In this circumstance, untreated sewage and garbage water will be deposited, untreated, into creeks, rivers, and Lake Ontario. This process can pollute our freshwater lakes with bacteria, pathogens, heavy metals, oils, pesticides, and nutrients which can cause undesired algae growth. The City is currently in Stage One of a five-stage program that aims to virtually eliminate CSO. This project serves as an example of how activities under the purview of individual municipalities can have a massive impact on a shared resource, the Great Lakes.
I am committed to advancing Toronto's legacy of leadership in freshwater conservation initiatives. In order to do so, we must continue to collaborate with municipalities across the continent through avenues such as the GLSCI. Stewardship of this invaluable freshwater resource is our collective responsibility.