The tailings dam at the Los Frailes gold-copper-lead-zinc mine, located at Aznalcóllar near Seville, failed in April 1998. It released approximately 5.5 million cubic metres of acidic, metal-rich water and approximately 1.3 to 1.9 million cubic metres of toxic tailings into the Agrio, Guadiamar and Los Frailes Rivers (WWF 2002). The contamination affected 62 kilometres of waterways and 4 286 hectares of land, including farmland in the fertile Guadiamar basin and part of the ecologically significant Doñana National Park – a Natura 2000 and World Heritage Site. The emergency construction of barriers stopped more extensive waste intrusion into the park, which is the largest reserve in Spain and significantly, home to 361 bird species (Grimalt et al. 1999).
From collection: Mine Tailings Storage: Safety Is No Accident