A/HRC/21/48 months after use, indicating limited efficacy and unanticipated levels of exposure for aquatic life. 9 14. Toxic substances in fracking fluids and resulting mud can be released into the surface water during the extraction, transport, storage and waste disposal stages. The storage of wastewater and other waste products may result in further contamination of water supplies due to spills, leaks and/or floods. These unintended releases can reasonably be expected to increase following the anticipated increase in the frequency and intensity of storms in the future, due to climate change. 15. Slurries and other solutions used or produced by extractive industries are commonly kept in impoundments, ponds or injected underground, from where, the waste is likely to leach arsenic, barium, mercury, lead, manganese, aluminium, chromium and other toxic substances into groundwater and private wells. Waste constituents of concern include radionuclides, such as lead, radium, radon and thorium; heavy metals, such as mercury and cadmium; other leaching agents, such as cyanide, sulphuric acid, arsenic; and sludge from evaporation ponds 16. In some instances, after the mining activity has been terminated, the mine water collected in abandoned pits, underground workings and aquifers contains radionuclides. The tailings from uranium extraction contain all the constituents of the ore, including 85 per cent of the initial radioactivity of the ore and 5 to 10 per cent of the uranium initially present in the ore. The decomposition of residual uranium in waste produces radon, an airborne, radioactive substance that can easily contaminate buildings, such as homes, schools and offices. The sludge also contains heavy metals and other contaminants, such as arsenic, as well as chemical reagents used during the milling process. Examples from around the world reveal a massive 30 million to 86 million tonnes of solid tailings from uranium mining operations in ponds or piles, per location.10 17. Gold cyanidation processes result in huge ponds of cyanide-laced waste, a major point source of cyanide release into groundwater. Over 30 large-scale accidental releases of cyanide into water systems have been reported since 1975, as a result of dam-related spills, transportation accidents and pipe failures. The catastrophic cyanide spill in Baia Mare, Romania, in 2000, affected the drinking water of 2.5 million people and the livelihood of over 1.5 million who depended on tourism, agriculture and fishing along the Tisza River in Hungary, Romania and Yugoslavia. Scientists estimate that it will take 10 to 20 years for most river life to return to the affected rivers. Many communities have voiced their concern over health effects suspected to be linked to cyanide contamination of the groundwater. 18. Exposed surfaces and waste rock in impoundments and ponds, or buried underground, can react and create new and additional waste from excavation and beneficiation, which can contaminate the surrounding surface and groundwater. Acid mine drainage (AMD), or acid rock drainage (ARD), is a highly acidic solution formed when sulfide-containing material is exposed to oxygen and water. When the acidic solution is carried into local surface waters or leaches into the groundwater, the loss of an aquifer or stream as a source of drinking water may result. The presence of cyanide in waste enables the solubility of heavy metals, such as mercury, arsenic, lead and other toxic metals, in water, exacerbating the impacts of these contaminants. 9 10 6 Elizabeth B. Kujawinski and others, “Fate of Dispersants Associated with the Deepwater Horizon Oil Spill,” Environmental Science and Technology, vol. 45 (2011), pp. 1298–1306. Peter Diehl, “Uranium Mining and Milling Wastes: An Introduction,” WISE Uranium Project, (last updated 18 May 2011). Available at http://www.wise-uranium.org/uwai.html.