Assessing the potential for downstream release of contaminated sediments associated with a recent fly ash spill

该奖项是根据2009年《美国复苏和再投资法案》(公法111-5)资助的。2008年12月22日凌晨，田纳西州哈里曼附近的S(田纳西河谷管理局)金斯敦发电厂的蓄水池出现裂缝，释放出约413万立方米的飞灰泥浆，其中约20%直接进入埃默里河。在大约3.2公里的范围内，埃默里河流入克林奇河，克林奇河在几公里后又流入田纳西河。我们的目标是评估这次飞灰泄漏对下游的影响，重点是：(1)下游河流沉积物和水域中飞灰的空间特征及其随时间的变化；(2)这些沉积物中飞灰中总的和不稳定的重金属的特征；(3)对飞灰沉积物迁移和相关重金属变化的预测；以及(4)与TVA协商制定有效的补救策略。鉴于TVA收集的河流水深测量背景数据，我们是否会使用Edge Tech 3100-P便携式海底剖面系统进行两次调查(一次是在飓风季节后立即进行，另一次是在飓风季节过后约4个月后)，以估计下游河段河床上沉积的飞灰数量。同时采集河床沉积物样本，以进行颗粒大小和重金属分析。这些数据将为受影响的河流系统的泥沙和地球化学动态预算提供基础。为了进一步推断这些数据，我们将进行耦合水流和泥沙输运的三维模拟，包括推移质、悬移质和溶解固体输运。因此，可以在受影响的埃默里河范围内对作为推移质和悬浮泥沙的飞灰以及相关的重金属进行合理的预测，如有必要，还可以将其送入克林奇-田纳西河流系统，而不需要对该系统的水力学和地球物理/地球化学史做出不必要的假设。这项快速反应调查的结果将有助于指导受影响地点的重建工作，并协助确定这些工作的优先次序。

ABSTRACTThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). In the early morning of December 22, 2008, a breach in the retaining pond at Tennessee Valley Authority?s (TVA) Kingston Power Plant near Harriman, Tennessee, released about 4.13 million m3 of coal fly ash slurry, about 20% of which directly entered the Emory River. Within about 3.2 km the Emory River discharges into the Clinch River, which in turn flows into the Tennessee River after several kilometers. Our objects are to evaluate the downstream impacts of this fly ash spill with emphasis on: (1) spatial characterization of fly ash within the downstream river sediments and waters and changes with time; (2) characterization of the total and labile heavy metals in the fly ash in these sediments; (3) predictions of changes in changes in fly ash sediment transport and associated heavy metals; and (4) development of effective strategies for remediation in consultation with TVA. Given the background data TVA has collected on river bathymetry, will we conduct two surveys (one immediately and one about 4 months later following the hurricane season) with the Edge Tech 3100-P portable sub-bottom profiling system to estimate the amount of fly ash deposited on the bed of downstream reaches. Concurrent river bed sediment samples will be collected for particle size and heavy metals analysis. These data will provide the basis for dynamic sediment and geochemical budgets for the affected reaches of the river systems. To further extrapolate these data, we will conduct 3-D modeling that couples flow and sediment transport, including bedload, suspended load, and dissolved solids transport. As such, reasonable predictions of fly ash transported both as bedload and suspended sediment, along with associated heavy metals, can be obtained within the impacted reach of the Emory River and, if necessary, into the Clinch-Tennessee fluvial systems without making unnecessary assumptions about the hydraulics and geophysical/geochemical history of the system. Findings from this rapid response investigation will help guide rehabilitation efforts at the affected site and assist with priority setting of these efforts.