This study presents an effective approach to tackle the challenge of long-term monitoring of contaminated groundwater sites where remediation leaves residual contamination in the subsurface. Traditional long-term monitoring of contaminated groundwater sites focuses on measuring contaminant concentrations and is applicable to sites where contaminant mass is removed or degraded to a level below the regulatory standard. The traditional approach is less effective at sites where risk from metals or radionuclides continues to exist in the subsurface after remedial goals are achieved. We propose a long-term monitoring strategy for this type of waste site that focuses on measuring the hydrological and geochemical parameters that control attenuation or remobilization of contaminants while de-emphasizing contaminant-concentration measurements. We demonstrate how this approach would be more effective than traditional long-term monitoring, using a site in South Carolina, USA, where groundwater is contaminated by several radionuclides. A comprehensive enhanced attenuation remedy has been implemented at the site to minimize discharge of contamination to surface water. The immobilization of contaminants occurs in three locations by manipulation of hydrological and geochemical parameters, as well as by natural attenuation processes. Deployment of our proposed long-term monitoring strategy will combine subsurface and surface measurements using spectroscopic tools, geophysical tools, and sensors to monitor the parameters controlling contaminant attenuation. The advantage of this approach is that it will detect the potential for contaminant remobilization from engineered and natural attenuation zones, allowing potential adverse changes to be mitigated before contaminant attenuation is reversed.

中文翻译：

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在部署了基于衰减的补救措施的地点改善对受污染地下水的长期监测

这项研究提出了一种有效的方法来应对长期监测受污染的地下水地点的挑战，在这些地点，修复会在地下留下残留污染。传统的地下水污染场地长期监测侧重于测量污染物浓度，适用于污染物质量被去除或降解到低于监管标准水平的场地。在实现补救目标后，在地下继续存在金属或放射性核素风险的场所，传统方法效果较差。我们为此类废物场地提出了长期监测策略，重点测量控制污染物衰减或再迁移的水文和地球化学参数，同时不强调污染物浓度测量。我们展示了这种方法如何比传统的长期监测更有效，使用美国南卡罗来纳州的一个地点，那里的地下水被几种放射性核素污染。已在现场实施了全面的增强衰减补救措施，以尽量减少向地表水排放污染物。通过操纵水文和地球化学参数以及自然衰减过程，污染物的固定发生在三个位置。我们提议的长期监测策略的部署将使用光谱工具、地球物理工具和传感器结合地下和地表测量，以监测控制污染物衰减的参数。