Building a dual-purpose water system

Distribution process serves dual purpose 39° F water is drawn through three new intake pipes, treated at the Island filtration plant, and directed through an existing cross-harbor tunnel to the John Street pumping station. Prior to entering the drinking water supply, the water is sent through heat exchangers and thermal energy is transferred from the Enwave system to the city system. Water enters the city side of the heat exchangers at 40° F and leaves at 55° F, with 15° F transferred from the water on Enwave's side of the heat exchanger. Physical separation between Enwave's system and the city's system is maintained via heat exchangers that are designed to facilitate the transfer of energy, not water. A single source of water provides coldness for Enwave's system and drinking water for the city. Source: Enwave

Three 63-inch outside diameter HDPE pipes stretch 3 miles out into Lake Ontario to draw 39° F water from 275 feet down. Source: Enwave

Toronto's water passes through many stages 1. Three intake pipes draw 39° F water from Lake Ontario at a depth of 275 feet. The water is then filtered and treated for the city's potable water supply. 2. At the energy transfer station (ETS), the icy cold water is used to cool Enwave's closed chilled water supply loop through pairs of heat exchangers. The ETS is adjacent to the city of Toronto's John Street pumping station. 3. Chilled water can bypass the cooling plant and continue to the customer building. If necessary, water can be further chilled by two, 4700 ton, steam-driven, centrifugal chillers. 4. Heat exchangers at the customer building cool the internal building loop, providing chilled water for the building cooling system. Source: Enwave

One of the 3-mile, 63-inch pipes is towed out into Lake Ontario. The pipe actually traveled more than 290 miles from the extruding plant to the assembly site to the Toronto lakefront. Photo: Enwave

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