对怀疑存在化学污染的现场进行基于风险的纠正措施分析，需要了解水通过土壤渗透到地下水位的速度。本报告对目前用于量化这些速率的物理/化学方法和数学模型进行了全面讨论，并根据现场条件提出了选择适当技术的建议。

This report reviews available resources and methods for obtaining data on diffuse natural groundwater recharge for site-specific assessments (e.g., Tier 2 and Tier 3 Risk Based Corrective Action analyses). Diffuse groundwater recharge is important because it affects the rate at which residual chemicals could be leached from the soil and migrate to groundwater. Accurate recharge estimates are essential for quantifying the risk to groundwater presented by residual chemicals in the vadose zone.