In October 1966, an intense precipitation event (190 mm in 24 h) broke an old tailings retaining structure in the “El Segundo” mining district in the western sector of Spain’s Sierra de Gador, generating a contaminated flood. The Pb-F rich mixture flowed for more than 12 km through the dry riverbeds, damaging infrastructures and crops. In March, 2010, over 40 years later, 41 samples were collected from boreholes and springs, along with eight sediment samples from near the tailings pond and along the dry riverbeds. The fluoride levels in the area’s groundwater were close to 1 ppm, surpassing the area’s normal geogenic levels, and in some cases exceeding the WHO maximum recommended value for drinking water, despite the time that has elapsed since the event. Less mobile elements, such as Pb and Zn, also had higher concentrations in the area affected by the sludge contamination, but did not significantly exceed the background geogenic values.

中文翻译：

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矿山渗滤液对碳酸盐含水层的影响（西班牙东南部）

1966 年 10 月，一场强降水事件（24 小时内 190 毫米）破坏了西班牙加多尔山脉西部“El Segundo”矿区的旧尾矿挡土结构，产生了受污染的洪水。富含 Pb-F 的混合物流经干涸的河床超过 12 公里，破坏了基础设施和农作物。40 多年后的 2010 年 3 月，从钻孔和泉水中收集了 41 个样品，以及从尾矿池附近和干燥河床沿线收集了 8 个沉积物样品。该地区地下水中的氟化物含量接近 1 ppm，超过了该地区的正常地质水平，并且在某些情况下超过了世卫组织饮用水的最大推荐值，尽管自事件发生以来已经过去了一段时间。移动性较低的元素，例如 Pb 和 Zn，