Fundão dam (Minas Gerais, Brazil) breached on 5 November 2015, releasing 50 million m³ of Fe ore tailings and dam materials into the upper Doce River system. The tailings travelled 670 km along the river system to the ocean. Starting on 17 November 2015, 6 days before the tailings reached the Doce River mouth, a water quality monitoring program with a daily sampling schedule was implemented by Samarco Mineração S.A. (Samarco) to assess the impacts on marine water and sediment quality. Between November 2015 and August 2017 water and sediment quality were monitored at 28 locations offshore from the Doce River mouth. The sampling areas were grouped by hydrological and metocean season (i.e., rainy and dry seasons and wave and wind climates), distance from the river mouth (<5 km, >5 km and within a Marine Protected Area), and water depth. The data were compared to the Brazilian water quality standards and prebreach conditions. Statistical tests were conducted to evaluate temporal and spatial trends and patterns. For the water quality parameters of relevance (total suspended solids, turbidity, total and dissolved Fe, Al, and Mn), pulses of concentration increases were observed right after the arrival of the plume in the coastal zone and during the subsequent rainy seasons. Exceedances of prebreach conditions were more frequent closer to the Doce River mouth. During the dry season, concentrations tended to decrease, reaching prebreach levels for a number of parameters, with small short‐term pulses associated with metocean factors. For sediment quality parameters of relevance (particle size, Fe, Al, and Mn), Fe was the only one that clearly resulted from the dam breach, which was mediated by river influence and oceanographic factors affecting particle size distribution. Results indicated that the Fundão dam failure did affect water and sediment quality in the Atlantic Ocean, with greater impacts closer to the river mouth and immediately after the arrival of the tailings plume, with concentrations gradually returning to preevent levels over time. Integr Environ Assess Manag 2020;16:643–654. © 2020 SETAC

中文翻译：

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丰达尾矿坝溃坝后，多西河口周围沿海地区的水和泥沙质量。

Fundão大坝（巴西米纳斯吉拉斯州）于2015年11月5日发生破坏，向Doce River上游系统释放了5000万立方米的铁矿石尾矿和大坝材料。尾矿沿着河流系统向海洋传播了670公里。从2015年11月17日开始，即尾矿到达Doce河口之前的6天，SamarcoMineraçãoSA（Samarco）实施了带有每日采样时间表的水质监测程序，以评估对海洋水和沉积物质量的影响。在2015年11月至2017年8月之间，对Doce River河口附近28个地点的水和沉积物质量进行了监测。根据水文和海洋季节（即雨季和旱季以及海浪和风的气候），距河口的距离（<5 km，> 5 km且在海洋保护区内）对采样区域进行分组。将数据与巴西水质标准和违约条件进行比较。进行统计测试以评估时空趋势和模式。对于相关的水质参数（总悬浮固体，浊度，总和溶解的Fe，Al和Mn），在羽流到达沿海地区之后以及随后的雨季期间，观察到浓度上升的脉冲。越接近Doce River河口，越容易出现过婚行为。在干旱季节，浓度趋于下降，许多参数均达到了预浸前水平，与海洋因素相关的短期脉冲很小。对于相关的沉积物质量参数（粒径，Fe，Al和Mn），Fe是唯一明显是由于大坝溃决而产生的参数，这是由河流的影响和影响粒度分布的海洋因素所介导的。结果表明，Fundão大坝的破坏确实影响了大西洋中的水和沉积物质量，在靠近尾矿口和尾矿羽流到达后立即产生了更大的影响，随着时间的推移，浓度逐渐恢复到事前水平。Integr环境评估管理2020； 16：643–654。©2020 SETAC