The vertical transport of contaminants from source areas is employed in many risk assessment models and screening tools in order to estimate the contaminant mass discharge (CMD) into underlying aquifers. The key parameters for estimating CMD are the contaminant source area and concentration, and the vertical water flux, the latter of which depends on the vertical hydraulic conductivity and the vertical hydraulic gradient in the subsurface. This study focuses on advancing the use of the combined membrane interface probe hydraulic profiling tool (MiHPT) to investigate the vertical hydraulic gradient across a clay till overlying a sandy aquifer at a contaminated site in Denmark. Only the HPT is necessary for the estimate of vertical hydraulic gradient. The hydraulic head, clay till thickness, and resulting vertical hydraulic gradients found using the MiHPT compared well with observations from nearby nested wells. The parameter with the largest discrepancy was the thickness of the clay till. The advantage of the MiHPT is its relatively quick depth discrete access to information regarding subsurface permeability, vertical hydraulic gradients and contaminant distribution across a site. In this case study, performance of additional dissipationtests during the HPT log to acquire determination of the vertical hydraulic gradient increased the cost by 3% compared to standard HPT logs.

中文翻译：

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使用 MiHPT 高级直推技术在粘土中进行垂直水力梯度估计

许多风险评估模型和筛选工具都采用了来自源区的污染物垂直迁移，以估计进入下伏含水层的污染物大量排放 (CMD)。估算 CMD 的关键参数是污染源面积和浓度，以及垂直水通量，后者取决于地下的垂直水力传导率和垂直水力梯度。本研究的重点是推进使用组合膜界面探针水力剖面工具 (MiHPT) 来研究在丹麦污染场地覆盖粘土直至覆盖沙质含水层的垂直水力梯度。估计垂直水力梯度只需要 HPT。液压头，粘土直到厚度，使用 MiHPT 发现的垂直水力梯度与附近嵌套井的观测结果进行了很好的比较。差异最大的参数是粘土的厚度。MiHPT 的优势在于其相对快速的深度离散访问有关地下渗透率、垂直水力梯度和整个场地的污染物分布的信息。在本案例研究中，与标准 HPT 测井相比，在 HPT 测井期间进行额外的耗散测试以确定垂直水力梯度的成本增加了 3%。MiHPT 的优势在于其相对快速的深度离散访问有关地下渗透率、垂直水力梯度和整个场地的污染物分布的信息。在本案例研究中，与标准 HPT 测井相比，在 HPT 测井期间进行额外的耗散测试以确定垂直水力梯度的成本增加了 3%。MiHPT 的优势在于其相对快速的深度离散访问有关地下渗透率、垂直水力梯度和整个场地的污染物分布的信息。在本案例研究中，与标准 HPT 测井相比，在 HPT 测井期间进行额外的耗散测试以确定垂直水力梯度的成本增加了 3%。