piping, and any heat exchangers. First major system in the United States Cornell University's Lake Source Cooling System uses Cayuga Lake as a heat sink to operate the central chilled water system for its campus and to also provide cooling to the Ithaca City School District. The system has operated since the summer of 2000 and was built at a cost of $55–60 million. It cools a 14,500 ton (51 megawatt) load. The intake pipe of the system is 3,200 m (10,498 ft) long and has a pipe diameter of 1,600 mm (63"), installed at a depth of 229 m (750 ft), allowing access to water temperatures between 3-5 C (37-41 F). The water is returned to the lake through a 1,200 mm (47") outfall pipe, 780 m (2,560 ft) long. The pipe selected for the project was Sclairpipe, made from high density polypropylene (HDPE). Estimated savings is an 80% reduction in fossil fuel previously required to operate a conventional electric cooling system. First system in Canada Since August 2004, a deep lake water cooling system has been operated by the Enwave Energy Corporation in Toronto, Ontario. It draws water from Lake Ontario through tubes extending into the lake, reaching to a depth of where the water is maintained at a constant 4°C, its temperature protected by a layer of water above it, called a thermocline. The deep lake water cooling system is part of an integrated district cooling system that covers Toronto's financial district, and has a cooling power of 59,000 tons (207 MW). The system currently has enough capacity to cool of office space. The installed deep lake cooling water intake line was 1,600mm (63") in diameter, 15,000 m (49,213 ft) long and installed at a depth of 85 m (278 ft) allowing access to water temperatures of between 3-5 C (37-41 F). The selected pipe was Sclairpipe, made from high density polyethylene (HDPE) resin. Water drawn from the depths of Lake Ontario is not circulated directly through fan coil units installed in commercial, or residential buildings. Instead, water from the Lake is circulated through a set of closed-loop heat exchangers in order to allow for a net transfer of thermal energy from the water-glycol mixture returning from buildings to the Lake water. The water-glycol mixture is part of a closed-loop district cooling system, pumped from a centralized location where the heat-exchangers are installed, back to the buildings