The much-noted 'Scraping Bottom' article in the most recent issue of National Geographic highlights the following points about water and the tar sands.
50 SQUARE MILES OF TAILINGS PONDS
"To extract each barrel of oil from a surface mine (in the Athabasca Valley, the industry) must heat several barrels of water to strip the bitumen from the sand and upgrade it, and afterward it discharges contaminated water into tailings ponds like the one near Mildred Lake. They now cover around 50 square miles." (p.44)
ONE OF THE LARGEST DAMS IN THE WORLD
"Mildred Lake...is now dwarfed by its neighbour, the Mildred Lake Settling Basin, a four-square-mile lake of toxic mine tailings. The sand dike that contains it is by volume one of the largest dams in the world." (p.43)
200,00 POUNDS OF WATER EVERY DAY
"And every day in the Athabasca Valley, more than a million tons of sand emerges from (rock) crushers and is mixed with more than 200,000 pounds of water that must be heated, typically to 175 degrees F, to wash out the gluey bitumen." (p.48)