Sam Ziemann From - Region of Waterloo

HYDROGEOLOGICAL ASSESSMENTSTRANGE STREET WATER SUPPLY CLASS EA UPDATEREGIONAL MUNICIPALITY OF WATERLOOBackground ReviewMarch 19, 2012presented some challenges, and therefore it was difficult to determine the horizontal extent andcontinuity of each of these layers.Aquitard 4 (ATE1/ATG1):Aquitard 4 corresponds to the Pre-Catfish Creek Till and Canning Drift. This unit is foundprimarily in the central, northern and western areas of the Region, and along the Nith River inthe west and southwest. As a result Aquitard 4 units were typically found to be discontinuousthroughout the Strange Street Well Field (Stantec, 2009), however, similar to the unitsassociated with Aquifer 3, delineation of these units was challenging as a result of the lack ofdeep boreholes.Bedrock:The Paleozoic bedrock geology beneath the Strange Street Well Field consists of the Salinaand Guelph Formations (OGS, 1991). The Salina Formation consists of interbedded dolostoneand shale with lenses of gypsum and anhydrite. Typically, groundwater extracted from theSalina Formation within the Region is of poor quality due to high concentrations of calcium andsulphide resulting from the dissolution of gypsum and anhydrite minerals. The GuelphFormation is a dolostone and represents an important aquifer to the east of Kitchener-Waterloonear Guelph, and to the south in the City of Cambridge. The contact between the Salina andGuelph Formations is interpreted to be present in the eastern portion of the Strange Street WellField (OGS, 1991).2.3.2 Local and Regional HydrogeologyThe most recent delineations of regional groundwater flow within Aquifer 1 and Aquifer 3, werepresented by AquaResource (2009). The general regional groundwater flow direction withinAquifers 1 and 3 is from west to east from the core areas of the Waterloo Moraine, including inthe Strange Street Well Field. Groundwater levels within Aquifer 1 decrease from a high ofapproximately 350 m AMSL near the core area of the Waterloo Moraine, to a low of310 m AMSL to the east of the well field. Groundwater flow within Aquifer 1 is predominantlyhorizontal and results from regional recharge within the core areas of the Waterloo Moraine,near St. Agatha, and local recharge where Aquitard 1 is absent and Aquifer 1 is exposed atground surface. Where Aquitard 2 is absent, a hydraulic connection between Aquifer 1 andAquifers 2/3 may exist, resulting in vertical flow and recharge to the deeper aquifer units.The hydrogeology of the Strange Street Well Field has been characterized by numerousstudies, the most prominent of which include:• K11 Aquifer Test (IWS, 1942)• TW3-74 (near K18) Aquifer Test (IWS, 1974)• K18 Aquifer Test (IWS, 1975)• K10A Aquifer Test (IWS, 1982);2.6 hls v:\01609\active\161110897_strange_st\planning\report\final hydrogeo assessment\final\fnl_rpt_120319.docx