Water Use by the Natural Resources Sectors In Alberta.

As a whole, the entire natural resources sector in Alberta is responsible for 2% of pollutants released to water in 2003.

The main concern is that high volumes of water are withdrawn, which could create stress in areas where water is scarce. However, the water withdrawn is usually returned to the source quickly, so consumption rates are low.

For oil and gas production, the main issue is that water use could be considered to be consumptive, meaning that it is not returned to the location from which it was withdrawn.  Water is either injected into oil reservoirs or, in the case of the oil sands, held for years in tailings ponds. 

Water use intensity (per unit of energy generation) is highest for hydroelectric installations, followed by nuclear and fossil fuel-fired plants.

Thermal-electric power generation

Thermal-electric power generation has the highest water withdrawal rate of all natural resources sectors in Canada.  It used 36 345 MCM of water in 2005, or 60 percent of the Canadian total.  Water was used mostly for cooling and thus was not consumed. Gross water use in the thermal-electric power generation industry has increased moderately since 1991. 

Water consumption levels are low in plants with open-loop cooling systems.  However, the volumes of withdrawal are high. Withdrawal levels could be decreased with closed loop systems, with the effect of increasing consumption due to evaporation

Most of the cost for thermo-electric generation originates from the construction, operation, maintenance of machinery used to withdraw, circulate, treat water.

Oil and Gas Industries

 From 2001 to 2005, the amount of water allocated to oil and gas industry in Alberta increased by 54% and accounted for 7% of Alberta’s total water allocations.  However oil/gas companies usually use significantly less than the amount they are allocated.

Surface-mining oil sands production uses 3.0 to 4.5 barrels of water (net)/ barrel of bitumen produced. In-situ oil sands production: uses ~1 barrel of water (net) per barrel of bitumen produced.

Currently, Natural Resources Canada scientists at CanmetENERGY (formerly CANMET Energy Technology Centre) are working with oil sands mining companies to develop technology that may reduce the water consumed by tailings ponds. Their goal is to decrease the net water use in mining operations to 2 barrels of water/barrel of bitumen.  This would result in dry tailings, eliminating the need for extensive tailings ponds and their associated environmental risk.

By 2015, oil sands productions expected to increase by two times.  The resulting increases in water requirements will place pressure on availability of water in Athabaska region.  Some companies have committed to improving their water-use efficiency so they can expand their operations without increased water allocations.

The oil refining industry uses water primarily for cooling, condensing and steam, with a relatively small amount consumed.  In 2005, the petroleum- and coal-products manufacturing industry used 869 MCM of water, 58% of it in the form of recycled water.  The industry requires high-quality water for its operations---41 % ($210 million) of its total water costs in 2005 were devoted to the treatment of intake water. 

Citation:

Natural Resources Canada. “Water Use by the Natural Resources Sectors - Facts” last modified October 14th, 2010,http://www.nrcan-rncan.gc.ca/com/resoress/publications/wateau/energ-eng.php


Mona Dai, Nov 7, 2010