Redistribution of arsenic and other contaminants at sites in New Jersey and Maine

砷在地下的行为反映了地下水补给动态中含水层中存在的氧化还原条件、与颗粒表面的相互作用、特定矿物相。我们建议在两个有砷污染的超级基金地点进行实地研究，在我们的调查期间，这两个地点都将进行积极的地下水处理。位于新泽西州南部的Vineland化学公司（ViChem）在过去的50年里，至少有数百吨的废物被分散到地表油、含水层、地下水地表水，以及河流、湖泊和河口沉积物中，这些沉积物远离原砷除草剂和杀菌剂生产设施的下游。我们的策略主要是通过分析监测井中已经存在的示踪剂样本，并将As和其他氧化还原敏感物种的行为与这些变化联系起来，来检查这种改变的流动方案的e补给动态。作为调查的一部分，我们将分析地下水的3H/3He、总[As]、As形态Fe、Mn、NO3、SO4、O2、PO4/3-、Si(oh)4、Ph、Eh和主要元素化学。将定期收集样品，以检查砷溶解度和地下砷运输动力学的关键控制。我们将收集和分析联合湖的一系列沉积物岩心，以重建As向下游迁移的历史，并估计向上移动到沉积物表面的As沉积物盘存比例。一套类似的地下水测量，旨在阐明对砷行为的控制，将在温斯洛普（ME）垃圾填埋场进行。As的来源是这种强烈减少羽流尚未解决，但从周围的自然土壤动员似乎是一个重大的可能性，这表明类似的As羽流可能发生在许多其他垃圾填埋场。与Vineland地点不同，Winthrop的水文地质非常复杂，因为水力导电性的空间变异性很大。除了3H/3He外，我们还建议采用地球物理测量技术（探地雷达和电阻率）来更好地约束地下水流动状况。我们将通过沿着垃圾填埋场下方的流动路径跟踪地球化学演化，并通过跟踪标记为SF6的再注入水羽的成分来研究As的动员过程。我们的研究将有助于更好地理解不同地球化学条件下从氧化到高度还原影响砷输运的过程。它们还可能有助于提高目前正在调查的一些超级基金场址的砷修复效率。

Arsenic behavior in the subsurface reflects redox conditions, interactions with particle surfaces, specific minerals phases present in the aquifer in the groundwater recharge dynamics. We propose field studies at two Superfund sites with As contamination, both of which will be under active groundwater treatment through the period of our investigation. The Vineland Chemical Company (ViChem) site in southern NJ, experienced dispersal of at least hundreds of tones of waste AS over five decades into surface oils, aquifer formations, groundwater surface waters, plus stream, lake, and estuary sediments far downstream from the original arsenical herbicide and fungicide production facilities. Our strategy will be to examin4e recharge dynamics of this altered flow regimen, primarily through analyzing samples from monitoring wells for tracers already present in the environment and to relate behavior of As and other redox sensitive species to those changes. As part of our investigation, we would analyze groundwater for 3H/3He, total [As], As speciation Fe, Mn, NO3, SO4, O2, PO4/3-, Si(oh)4, Ph, Eh and major element chemistry. Samples would be collected periodically, to examine critical controls on As solubility and dynamics of subsurface As transport. We will collect and analyze a series of sediment cores in Union Lake in order to reconstruct the history of As migration downstream, and to estimate the proportion of As sediment inventory mobilized upward towards the sediment surface. A similar set of groundwater measurements, directed at elucidating controls on As behavior, would be conducted at the Winthrop (ME) Landfill site. Sources of As to this strongly reducing plume are unresolved, but mobilization from surrounding natural soils appears to be a significant possibility, suggesting that similar As plumes could occur at many other landfills. Differing from the Vineland site, the hydrogeology at Winthrop is very complex due to large spatial variability of hydraulic conductivity. We propose to better constrain the groundwater flow regime by employing geophysical survey techniques (ground penetrating radar and resistivity) in addition to 3H/3He. We will study As mobilization processes by following the geochemical evolution along a flow path underneath the landfill and by tracing the compositions of a plume of re- injected water labeled with SF6. Our studies will contribute to a better understanding of the processes affecting As transport under different geochemical conditions ranging from oxidizing to highly reducing. They could potentially also contribute to an increase in efficiency of As remediation at a number of Superfund sites currently under investigation.