Energy sector

Note: Data concerning water use by Alberta’s oil and gas industry are derived from Current and Future Water
Use in Alberta, produced by Alberta Environment.

• The energy sector includes the thermal power generation industry, the upstream (extraction) and downstream (processing/upgrading) oil and gas industries, and the hydroelectric power generation industry.
• The sector as a whole was responsible for less than 2 percent of reported pollutant releases to water in 2003.
• The main water issues facing the thermal-electric power generation industry relate to its high withdrawal volumes, which can stress regions with low water availability. However, most of the water withdrawn is quickly returned to its source, so consumption rates in the industry are low.
• Unlike the thermal-electric power generation industry, nearly all water use for oil and gas production could be considered to be consumptive, i.e. it is either injected into oil reservoirs or, in the case of the oil sands, held for years in tailings ponds. In addition, the oil and gas industry must carefully manage wastewater discharges to avoid contamination of aquatic ecosystems.
• All of the water used by the hydroelectric power generation industry flows through the hydroelectric installations; none is consumed.
• 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 used 36 345 MCM of water in 2005, or 60 percent of the Canadian total. Almost all of this use is for cooling and is non-consumptive. Gross water use in the thermal-electric power generation industry has increased moderately since 1991, and the industry has the highest gross water use by far in the natural resources sectors.
• In addition to their impact on local water availability, the large surface-water withdrawals of the thermal-electric power generation industry can kill organisms that are trapped against intake structures (impinged) or swept up (entrained) with water intake. This impact on aquatic organisms is an important concern for the industry from both environmental and economic perspectives. Aquatic organisms can clog cooling-water intakes and cost companies millions of dollars per year in maintenance and lost power generation.
• Water consumption by Canada’s thermal-electric power generation industry is low due to the high use of open-loop cooling systems. Wide-scale adoption of closed-loop systems would yield major reductions in water withdrawals with slight increases to consumption (mostly to evaporative losses). This has been the result in the United States, where closed-loop systems are more common.
• The thermal-electric power generation industry spent $99.2 million on water in 2005, equivalent to an average of $0.003 per cubic metre (m³) gross water use. The majority of these costs were for the construction, operation and maintenance of water withdrawal, circulation, treatment and discharge machinery. A small percentage was paid to provinces, territories and municipalities in the form of user fees or licensing fees.
• Water allocation to the oil and gas industry in Alberta grew by 54 percent from 2001 to 2005 and accounted for approximately 7 percent (694 MCM) of Alberta’s total water allocations in 2005. In many cases, however, oil and gas companies use much less than the amount they are allocated.

• Surface-mining oil sands production uses 3.0 to 4.5 barrels of water (net) per barrel of bitumen produced. In-situ oil sands production, however, uses about one barrel of water (net) per barrel of bitumen produced. In some in-situ operations, saline groundwater replaces some or all of the freshwater requirements for extraction. Thus, for freshwater only, the average net value is 0.6 to 0.9 barrels of water per barrel of bitumen produced via in-situ extraction. Some in-situ projects in the oil sands recirculate as much as 90 percent of their water.
• Natural Resources Canada scientists at CanmetENERGY (formerly CANMET Energy Technology Centre) in Devon, Alberta, are working with oil sands mining companies to develop technology that may reduce the water consumed by tailings ponds. The goal is to decrease the net water use in mining operations to two barrels of water per barrel of bitumen produced. This decrease would result in dry tailings, eliminating the need for extensive tailings ponds and their associated environmental risk.
• Oil sands production is projected to increase two-fold by 2015. Associated increases in water consumption are expected to put pressure on water availability in the Athabasca River basin. Recognizing this, some companies have committed to improving their water-use efficiency so they can expand their operations without increased water allocations.
• In addition to water availability concerns, oil sands projects affect water quality. Water recovered from oil sands surface-mine tailings has a high salt content and is toxic, due to naphthenic acids dissolved from the oil sands. Tailings ponds in Alberta now cover more than 70 square kilometres.
• Oil sands mining operations operate under a zero-discharge policy, meaning that they contain all wastewater and runoff on-site. Any water released from mining sites is treated and monitored to avoid negative impacts to aquatic ecosystems.
• The downstream oil and gas industry manufactures petroleum and coal products for the marketplace. Like other manufacturing industries, it 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, the majority (58 percent) of it in the form of recycled water.
• The downstream oil and gas industry requires high-quality water for use in its production processes. To meet this need, 41 percent of its total water costs in 2005 were devoted to the treatment of intake water. Overall, the industry spent $210 million on water in 2005.
• Several downstream oil and gas companies have developed innovative practices to recycle water and decrease their impact on freshwater quantity and quality.
• Effluent quality for the oil and gas industry as a whole is very good. Oil and gas companies were responsible for less than 1 percent of pollutant releases to water, as reported to the NPRI in 2003.

Hydroelectric power generation

• Canada’s share of energy from hydroelectric power generation is greater than that in any other country. Large-scale hydro generates almost 60 percent of Canada’s electricity. Canada has also diverted more water by damming rivers for hydro than any other country.
• The construction of dams can significantly alter local ecosystems, but ongoing impacts are limited.
• While a few sites are being developed for new large-scale hydroelectric production projects, small-scale dams and run-of-river projects are receiving increased attention. Small-scale projects can have less of the environmental and social impacts associated with large dams. It has been estimated that 5500 sites in Canada are technically feasible for small-scale hydroelectric production.