Water Quality

Water Quality1 2

Canadians are custodians of the most significant reservoirs of fresh water in the world. Annually, 9% of the world's renewable water supply flows from Canadian rivers. Lakes cover 7.6% of the Canadian landmass, wetlands 14% and perennial snow and ice 2%. The Great Lakes, with about 20% of the world's fresh surface water, make up the largest freshwater lake system in the world.

Canada has rigid regulations with respect to the use of water for industrial purposes and the disposal of water from processing plants or oil and gas production. Water for industrial use may not be removed from wells, streams or other water bodies without approval of the responsible regulatory authority. This process water must be treated and returned to the natural environment.

In Alberta, the main uses of ground water are: waterflood injection for enhanced oil recovery, municipal water supplies, and non-irrigation agricultural use. The oil and gas industry receives approximately 2.6% of all surface water licenses. Under the government's “Alberta's Water Conservation and Allocation Policy for Oilfield Injection” all applicants are required to evaluate alternative sources of water before applying for a fresh water license.

All water produced from oil and gas wells must be returned to the underground zone of origin, or to another zone approved by the regulatory authority. Water discharged from processing facilities must be treated and disposed of into an approved underground formation, or conditioned to rigid standards before being discharged to a stream or other surface water body.

Water is essential for the conversion of oil sands into a variety of oil products. Currently, 3 to 4 cubic metres of water are used for each cubic metre of product. As extraction operations mature, water use is expected to be reduced to two cubic metres per cubic metre of product.

Although oil sands operations have minimized their water use, attempts have been made at further reductions:

  • In surface mining operations, operators are attempting to increase the recycle component by improving equipment design to utilize and treat poorer quality water; accelerate consolidation of tailings to release water back into the cycle; use more air cooling; and minimize operating inventories.
  • In in–situ operations, the aim is to improve water use through: water treatment; greater use of brackish and saline water including testing desalination technologies; reducing water use through the addition of solvents to decrease bitumen viscosity and improve oil displacement; improvements in the steam–to–oil ratio through improved reservoir modeling and well placement; and pursuit of new no-water technologies.

Driving forces in the development of technologies to increase water use efficiency are:

  • Public concern about potable water availability and contamination; conservation of natural ecosystems, and keeping water withdrawals to prescribed limits to maintain natural fluctuations in rivers and lakes.
  • Industry's desire to minimize water use so as to reduce operating costs related to water handling and storage.