Enabling Improved Public Health Protection by Assessing the Vulnerability of Naturally- and Hydraulically-Fractured Aquifers.

超过25%的加拿大人依赖地下水作为饮用水。许多水传播疾病的例子都归因于被认为是安全的地下水源，但被病原体污染了（例如，Walkerton，ON，2000年5月）。这些疾病的爆发不是随机分布的，而是更有可能发生在断裂的岩石含水层中。在加拿大，70%的区域含水层位于断裂基岩中，通常的做法是水力压裂（压裂）这些含水层以增加产水量。由于在含水层和地面之间建立了水力联系，这种做法会进一步增加这些含水层受病原体污染的脆弱性。 拟议的研究结合了现场和实验室规模的实验与建模，以调查压裂基岩威尔斯井对这些含水层的病原体污染的脆弱性的影响。它将集中在我们的概念理解的进步病原体运输和保留在骨折。这种概念性或机械性的方法将使通过这项工作获得的知识能够应用于不同的地点和条件。以下研究问题将得到解决：1）可以压裂基岩井诱导含水层和表面之间的水力连接; 2）病原体的大小对运输和保留在裂缝中的影响是什么; 3）什么样的影响以及操作（即泵循环和流量）对病原体的运输和保留;和4）如何将实验室规模的研究结果与现场规模联系起来？ 这项研究将为立法者提供所需的知识，以制定有关水源保护和水力压裂的循证政策，直接影响加拿大人的公共健康。它还将为从业人员提供制定基岩含水层保护计划所需的知识，以及评估基岩含水层脆弱性的工具。最后，它将为10名HQP提供极好的培训机会。

More than 25% of Canadians rely on ground water for their drinking water supply. Many instances of waterborne illnesses are attributed to groundwater sources that were considered safe and became contaminated by pathogens (e.g., Walkerton, ON, May 2000). These disease outbreaks are not randomly distributed; rather they are more likely to occur in fractured rock aquifers. In Canada, 70% of the regional aquifers occur in fractured bedrock, and it is common practice to hydraulically fracture (frack) these aquifers to increase the water yield. This practice can further increase the vulnerability of these aquifers to pathogen contamination due to the induction of hydraulic connections between the aquifer and ground surface. The proposed research combines field- and laboratory-scale experiments with modeling to investigate the effects of fracking bedrock wells on the vulnerability of these aquifers to pathogen contamination. It will focus on the advancement of our conceptual understanding of pathogen transport and retention in fractures. This conceptual, or mechanistic, approach will enable the application of the knowledge gained through this work to different sites and conditions. The following research questions will be addressed: 1) Can fracking a bedrock well induce hydraulic connections between the aquifer and the surface; 2) What is the effect of pathogen size on transport and retention in fractures; 3) What effect does well operation (i.e. pump cycling and flow rate) have on pathogen transport and retention; and 4) How can laboratory-scale findings be linked to the field scale? This research will provide the knowledge required for legislators to develop evidence-based policy regarding source water protection and hydraulic fracturing that directly affects the public health of Canadians. It will also provide practitioners with the knowledge required for developing bedrock aquifer protection plans, and tools for assessing bedrock aquifer vulnerability. Finally, it will provide excellent training opportunities for 10 HQP.