Nature and Origin of Pristine Groundwater in Confined Glacial Aquifers in the Simcoe Lowland, Ontario

该项目涉及对乔治亚湾以东10公里处的Elmvale村为中心的Simcoe县部分地区砂石含水层中的地下水进行的研究。这一地区的地下水具有特殊的特点，最明显的是，许多自流井位于15至70米深处。这些井中的大多数产出的水都是淡水、饮用水和纯净水，这意味着来自人类活动(包括农业)的水中没有化学成分(即没有人为化学物质)，只有非常低的微量元素。新鲜的纯净地下水在加拿大和其他地方极其罕见。这项研究的目的是确定这类人类活动原始水和该地区含水层中其他水的来源和化学特征。一种可能性是，原始水部分是数千年前冰川时代的残余水，因此一个目标是估计多少年后原始水才会消失，取而代之的是新的更年轻的地下水。原始地下水从流动的自流井中排出，地下水从许多其他井中抽出，为农村人口和埃尔姆维尔提供服务。在自流地区几公里范围内的沙砾堆积的高地林区，通过降雨和融雪的渗透补充含水层。原始地下水的另一种可能性是，它不是冰川时代，而是通过在地下流动时的净化过程获得其原始特征。这项研究将评估这两种可能性。该项目将应用新型设备，其中一种已于2018年10月提交专利申请，将安装在钻孔中进行采样，并监测地下水中的压力和温度分布。这些设备将以相对较低的成本提供比传统监测井多得多的信息。除了回答有关Elmvale地区稀有类型地下水来源的问题外，这项研究还将评估这种新的地下水监测方法的价值。这一点很重要，因为一般来说，加拿大乃至全世界的地下水监测很差，这严重限制了以科学为基础的地下水管理的前景。埃尔姆维尔地区最适合于这项研究，因为其他研究人员以前曾进行过其他类型的相关调查，为这项拟议的工作奠定了良好的基础。

This project concerns a study of groundwater in sand/ gravel aquifers in part of Simcoe County ON, centred around the Village of Elmvale, 10 km east of Georgian Bay. Groundwater in this area has exceptional characteristics, most notably, many flowing artesian wells at depths between 15 and 70 m. Most of these wells yield water that is fresh, potable and pristine, meaning that there are no chemical constituents in the water derived from human activities including agriculture (i.e. no anthropogenic chemicals), and only very low trace elements. Fresh pristine groundwater is extremely rare in Canada and elsewhere. This study is aimed at determining origins and chemical characteristics of such anthropogenically pristine water and of the other water in the aquifers in the area. One possibility is that the pristine water is in part remnant glacial-age water many thousands of years old, so an objective will be to estimate how many decades will pass before the pristine water disappears, replaced by new younger-aged groundwater. The pristine groundwater is discharging from flowing artesian wells, groundwater is pumped from many other wells in serving the rural population and Elmvale. The aquifers are replenished by infiltration from rainfall and snowmelt in an upland forested area of sand and gravel deposits within a few km of the artesian area. Another possibility for the pristine groundwater is that it is not glacial age but acquires its pristine characteristics by purification processes as it flows in the ground. This study will assess these two possibilities. This project will apply new types of devices, one of which has a patent application submitted in October 2018, to be installed in drill holes for sampling and for monitoring pressure and temperature distribution in the groundwater. These devices will provide, at relatively low cost, much more information than conventional monitoring wells. In addition to answering questions about origin of the rare type of groundwater in Elmvale area, this study will provide an assessment of the value of this new approach to groundwater monitoring. This is important because generally groundwater in Canada and the world at large is poorly monitored, which severely limits prospects for science- based groundwater management. The Elmvale area is most appropriate for this study because other researchers have previously conducted other types of related investigations that serve well to set the stage for this proposed work.