Project 4: Dynamic Transport and Exposure Pathways of Contaminants in Karst Groun

项目总结 拟议的项目研究与超级基金有关的有机污染物的去向和迁移，以及 控制其移动性、持久性、分布和走向潜在暴露和/或路径的进程 岩溶地下水系统中的修复带。该项目的具体目标是描绘命运的特征 以岩溶地下水系统为代表的污染物运移过程和浓度分布 通过可变管道和/或扩散主导流动，就像在波多黎各北部发现的那样。这一地区是 保护局研究超级基金危险化学品暴露及其潜力的工作重点领域 波多黎各的早产率是美国司法管辖区中最高的， 全球排名第二，仅次于马拉维。该项目的重点是氯化挥发性有机化合物 (CVOCs)和邻苯二甲酸盐作为模型污染物，因为它们普遍存在，并已被证明具有 潜在的健康影响。研究将建立在物理、数据和协作研究基础设施的基础上 由调查人员在项目的前三年开发。 岩溶地下水系统提供了美国40%以上的饮用水地下水，开发 在可溶岩石中，如石灰岩和白云岩。这些系统中的流动可能通过裂缝发生， 管道和岩石母体。在这样的系统中，管道可以将水和污染物从直接 源和/或扩散流，并将其快速输送到潜在暴露点，如弹簧。 它们还可以将污染物输送到“诱捕”扩散流区，这可能导致长期储存和 随后污染物的释放。发展评估和预测污染物迁移和 在这些类型的含水层中潜在暴露于污染物对于了解和预防 地下水中的污染物对健康的影响。 该项目将描述和量化影响喀斯特地区污染物去向和迁移的因素。 系统。利用实验数据和现场测量，污染物的时空分布和 将对传输特性进行表征、量化和统计建模。基础知识 从实验室规模的水力学和运输实验中开发出来的模型将整合到现场- 通过使用地质统计学方法进行刻度测量和示踪测试。在现场范围内，污染物 将测量波多黎各北部岩溶系统中地下水井和泉水的浓度 在雨季和旱季。现场规模的模型将填充历史污染、水质、 和来自波多黎各北部岩溶地下水的水文地质数据，用于描述空间和 污染物分布的时间变化，提供了预测潜在动态接触的能力 在岩溶地下水系统中减少污染物，并制定保护公众健康的战略。

PROJECT SUMMARY The proposed project studies the fate and transport of Superfund-related organic contaminants and the processes controlling their mobility, persistence, distribution, and paths toward potential exposures and/or remediation zones in karst groundwater systems. The project's specific aims are directed at characterizing fate and transport processes and concentration distributions of contaminants in karst groundwater systems typified by variable conduit and/or diffusion dominated flow, as those found in northern Puerto Rico. This region is the focal area of PROTECT's work to study exposure to Superfund hazardous chemicals and their potential contribution to high rates of preterm birth in Puerto Rico, which are the highest among U.S. jurisdictions, second second only to Malawi globally. The project focuses on chlorinated volatile organic compounds (CVOCs) and phthalates as model contaminants because they are ubiquitous and have been shown to have potential health impacts. The research will build on the physical, data, and collaborative research infrastructure developed by the investigators during the first three years of the project. Karst groundwater systems, which provide over 40% of the groundwater used for drinking in the U.S., develop in soluble rocks, such as limestone and dolomites. Flow in these systems may occur through fractures, conduits, and the rock matrix. In such systems, conduits can concentrate water and contaminants from direct sources and/or diffuse flow and convey them rapidly to potential-exposure discharge points such as springs. They can also convey contaminants to "trapping" diffuse-flow zones, which can result in long-term storage and subsequent release of contaminants. Developing the ability to assess and predict contaminant transport and potential exposure to contaminants in these type of aquifers is essential to understanding and preventing health effects stemming from contaminants in the groundwater. This project will characterize and quantify the factors affecting fate and transport of contaminants in karst systems. Using experimental data and field measurements, spatiotemporal contaminant distributions and transport properties will be characterized, quantified and statistically modeled. Fundamental knowledge developed from hydraulic and transport experiments in laboratory-scale models will be integrated into field- scale measurements and tracer tests through the use of geostatistical methods. At the field scale, contaminant concentrations in groundwater wells and springs in the karst system of northern Puerto Rico will be measured during wet and dry seasons. Field-scale models will be populated with historical contamination, water quality, and hydrogeologic data from the karst groundwater of northern Puerto Rico, and used to describe spatial and temporal changes in contaminant distribution, providing the ability to predict potential dynamic exposure to contaminants in karst groundwater systems and establish strategies to protect public health.