Abstract Chlorinated volatile organic compounds are common constituents observed at many contaminated groundwater sites. Common industry practice has been to measure these constituents in groundwater on a weight concentration basis (e.g. µg/l, mg/l). This paper highlights the use of molar-based concentrations, especially in the case of parent-daughter degradation sequences commonly observed with the chloroethene, chloroethane, and chloromethane families of compounds. Converting to molar-based concentrations provides the practitioner greater insight into groundwater plume behavior including better evaluation of degradation processes, remedial progress, possible commingling, and/or sourcing. For example, this paper provides a tank analogy to evaluate whether the commonly misinterpreted observation of “DCE-stall” may be occurring at a site. Multiple examples of the benefits of using molar-based concentration data are also summarized in a project case study presented herein. As demonstrated in this paper, molarity does provide better clarity and can be a powerful evaluation tool in the groundwater practitioner’s toolbox.

中文翻译：

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摩尔浓度提供更好的清晰度——在评估氯化挥发性有机化合物受影响的地点时使用基于摩尔的数据

摘要 氯化挥发性有机化合物是在许多受污染的地下水地点观察到的常见成分。常见的工业实践是根据重量浓度（例如 µg/l、mg/l）测量地下水中的这些成分。本文重点介绍了基于摩尔浓度的使用，特别是在氯乙烯、氯乙烷和氯甲烷家族化合物中常见的母子降解序列的情况下。转换为基于摩尔的浓度可以让从业者更深入地了解地下水羽流行为，包括更好地评估降解过程、补救进展、可能的混合和/或来源。例如，本文提供了一个储罐类比来评估通常被误解的“DCE 失速”现象是否可能发生在某个地点。此处介绍的项目案例研究还总结了使用基于摩尔浓度数据的好处的多个示例。正如本文所证明的，摩尔浓度确实提供了更好的清晰度，并且可以成为地下水从业者工具箱中的强大评估工具。