Golder, Edmonton, Alberta, Canada.
Golder, Turin, Italy.
Integr Environ Assess Manag. 2020 Sep;16(5):643-654. doi: 10.1002/ieam.4309. Epub 2020 Aug 22.
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.
2015 年 11 月 5 日，巴西米纳斯吉拉斯州的 Fundão 大坝决堤，5000 万立方米的铁尾矿和大坝材料涌入多西河流域上游。尾矿沿着河流系统行进 670 公里到达海洋。从 2015 年 11 月 17 日开始，也就是尾矿到达多西河河口前 6 天， Samarco Mineração S.A.（Samarco）启动了一项水质监测计划，每天进行采样，以评估对海洋水质和沉积物质量的影响。2015 年 11 月至 2017 年 8 月，在多西河河口以外的 28 个地点对水质和沉积物质量进行了监测。采样区域按水文和气象季节（即雨季和旱季以及风浪气候）、距河口的距离（<5 公里、>5 公里和在海洋保护区内）和水深分组。将数据与巴西水质标准和决堤前的条件进行了比较。进行了统计检验以评估时间和空间趋势和模式。对于相关的水质参数（总悬浮固体、浊度、总铁、溶解铁、铝和锰），在潮水到达海岸带和随后的雨季期间，观察到浓度增加的脉冲。在更接近多西河河口的地方，超标情况更为频繁。在旱季，浓度往往会下降，许多参数的浓度达到决堤前的水平，而与气象因素有关的短期脉冲。对于相关的沉积物质量参数（粒径、铁、铝和锰），只有铁明显是由大坝决堤引起的，这是由河流影响和影响颗粒大小分布的海洋因素介导的。结果表明，丰当大坝决堤确实影响了大西洋的水质和沉积物质量，在更接近河口的地方和尾矿潮到达后立即受到更大的影响，随着时间的推移，浓度逐渐恢复到事件发生前的水平。综合环境评估与管理 2020；16：643-654。© 2020 SETAC。
