Quantification of groundwater contribution to fecal and nutrient pollution at beaches of the Great Lakes

五大湖的海滩是3000多万人的重要娱乐场所，但由于水质差，许多海滩经常因海滩警告而无法进入。这具有严重的经济和社会影响。政策和管理办法在改善泳滩水质方面不足，因为人们对所有污染源的影响，包括地下水的潜在重要作用了解甚少。因此，目前的决策是在缺乏这种可靠的定量科学的情况下做出的，而且往往效率较低。了解地下水对水质退化的影响以及如何管理地下水对水质退化的贡献是复杂的。它不仅需要了解特定的地下水污染源（例如，化粪池系统，漏水的下水道，农业），还需要了解地下水中污染物的行为和运动及其向浅水排放的基本过程（水文，生物地球化学和微生物）。

The beaches of the Great Lakes are an important recreational outlet for over 30 million people, yet because of poor water quality many are often inaccessible due to beach advisories. This has severe economic and societal implications. Policy and management approaches have been insufficient in improving the beach water quality as the contribution of all pollution sources, including the potentially significant role of groundwater is poorly understood. Decisions are therefore currently made in the absence of this sound quantitative science and tend to be less effective. To understand the impact of and how to manage the contribution of groundwater to the degrading water quality is complex. It requires knowledge of not only specific groundwater pollution sources (e.g., septic systems, leaky sewers, agriculture) but also knowledge of the fundamental processes (hydrological, biogeochemical, and microbial) underlying the behavior and movement of pollutants in the groundwater and their discharge to the shallow waters.