Water & Biodiversity
What are the Issues?
Many parts of the world face a scarcity of clean water, and the crisis is expected to grow. Over the past century, world water withdrawals have increased almost twice as fast as population growth, and in many places currently exceed recharge capacity. In some areas, industrial, residential and agricultural activities have impaired water quality. According to the United Nations, if present consumption patterns continue, two-thirds of the world’s population will live in water-stressed conditions by the year 2025.
The use of freshwater greatly varies by country and region; data on water use by sector and region is not as robust as experts would like it to be. That being said, the agricultural sector is by far the biggest user of water, accounting for almost 70 percent of all withdrawals, and up to 95 percent in developing countries. In some countries, such as the United States, hydroelectric power is the largest category of water withdrawals. At the same time, in the United States, water use for refining and for non-hydroelectric energy generation represents only a small fraction of total freshwater consumption.
Like other sectors of society, businesses, including the energy industries, require water and thus can play a constructive role in responding to this crisis through continuing improvements in responsible water management. There are opportunities for the energy industries to manage water issues within their sphere of influence so as to contribute to the world’s need for continued water supply and quality:
"Upstream" Energy Supply Including Impacts on Water and Biodiversity
During the oil extraction process, large quantities of water, which are combined with suspended and dissolved solids, are brought to the surface. The extracted water may contain a number of highly toxic substances. In order to avoid impacts on water and local ecosystems, this wastewater must be properly managed and treated.
The physical presence of offshore oil rigs can have impacts on marine ecosystems. For example, fish and animal breeding grounds can be disrupted by the physical rigs and by the presence of oil. Oil companies continue to improve planning and assessment processes that mitigate these impacts via design, placement, and operational decisions. Similarly, coal companies continue to address possible operational impacts that include acid mine drainage (AMD) which is acidic runoff that can dissolve heavy metals such as copper, lead and mercury into ground and surface water, leading to water pollution.
Midstream Water Impacts
During the transportation of oil, there is the risk of spills, particularly during transfers onto tankers, from tanker to rail, or from rail car to storage facility. These small spills, along with leaks from pipelines, result in approximately 15–20 million gallons spilled annually. While large tanker spills are infrequent, the impact on marine and shore ecosystems, fisheries and human health can be destructive. Companies are using double-hulled tankers and pipeline integrity management to prevent incidents that could adversely affect water.
Prevention and management of major oil spills continues to improve, with oil companies working with government agencies and universities to develop better prevention and response systems and plans. Regulation and technology solutions have also been enacted along the value chain to reduce water pollution and use.
Downstream Water Impacts: Refining and Electricity Generation
Refineries consume significant amounts of water for production processes, and are continually working on ways to protect groundwater and surface water from contamination, for instance, through fitting oil storage tanks with double bottoms and improving filtration and treatment processes.
Power generation requires a reliable, abundant, and predictable source of water primarily for cooling. As a result, water considerations are becoming an important part of the permitting process for new power projects. Globally, industrial uses of water are substantial, accounting for some 20% of freshwater withdrawals. Of this share, 57-69% is used for hydropower and nuclear power generation. Given that the production of energy through nuclear and hydroelectric plants requires large supplies of water, this water must be carefully managed to avoid impacts on water quality.
What are the Solutions?
Energy providers and industrial consumers are working to increase efficiency associated with water use. Shifts to non-hydroelectric renewables such as solar, geothermal, and wind, which are less water intensive, may help to achieve reductions in the amount of water needed for energy production.
In the United States, the Clean Water Act and regulations proposed by the EPA have the potential to impact the design of electricity generators. The EPA has proposed an innovative water quality trading system, under the Clean Water Act, that would allow for water quality trading between "point and non-point sources" within a watershed. Additionally, the private sector is exploring innovations in cooling systems, alternative Water Sources (such "non-traditional" waters include treated municipal wastewater and untreated "gray" water), power plant/watershed interrelationships and integrated water use planning.
Further advances in profiling water demands, treatment technologies, and watershed characterization, will help to minimize impacts of energy on water quantity and quality.