Sam Ziemann From - Region of Waterloo

HYDROGEOLOGICAL ASSESSMENTSTRANGE STREET WATER SUPPLY CLASS EA UPDATEREGIONAL MUNICIPALITY OF WATERLOOResults for Test WellMarch 19, 2012ATE1 (Aquitard 4):AFF1 (Aquifer 4):A greyish brown to brown silty clay unit believed to correspond toCanning Drift Till was found from 279.4 m AMSL (65.8 m BGS) to275.8 m AMSL (69.5 m BGS).A vertically extensive sand and gravel aquifer corresponding to AFF1(Aquifer 4) was identified between 275.8 m AMSL (69.5 m BGS) and265.2 m AMSL (80.0 m BGS).ATG1 (Aquitard 4): Silty clay to sandy silt till was observed to overlie bedrock from265.2 m AMSL (80.0 m BGS) to 263.3 m AMSL (81.9 m BGS). Thesedeposits were identified as Pre-Canning Coarse Till.Bedrock:Bedrock was encountered at a total depth of 81.9 m BGS(263.3 m AMSL). The dark grey limestone was identified as the GuelphFormation and was observed to extend to the base of the borehole at262.6 m AMSL (82.6 m BGS).Figure 4 presents cross-section A-A’, which extends across the Strange Street Well Field in aneast west direction. The cross-section location is shown in Figure 2. The most significantchange in the hydrostratigraphic interpretation based on the most recent drilling results is thelocal absence of ATB2 at K-SS-TW1-11, which confirms the unit is not continuous in the area asobserved by the presence of ATB2 300 m west at SS13-99 and about 400 m east at SS07-99.ATB1 (Aquitard 1) was confirmed to be absent at K-SS-TW1-11, as observed at nearbymonitoring well SS13-99, but is interpreted to be present further to the west along the flank ofthe Waterloo Moraine.4.3 WELL CONSTRUCTIONThe test well design was completed in consultation with Gerrits using the information collectedfrom the advancement of the initial borehole (K-SS-OW1A-11) and grain size analysiscompleted on the samples collected during the advancement of K-SS-TW1-11. The targetdepth for the screen installation was the thick sand and gravel to gravel sequence observed atthe base of AFB2 (Aquifer 1). The well construction activities for Test Well K-SS-TW1-11consisted of the following:• Beginning March 1, 2011, a 254 mm OD temporary well casing was installed using air rotarydrilling techniques to a depth of 19.8 m BGS;• On March 2, 2011, a 154 mm OD steel casing was installed using air rotary drillingtechniques to a depth of 28.9 m BGS;• On March 3, 2011, a 127 mm diameter telescopic screen was installed from 21.3 m to27.5 m BGS using a K-packer. The screen is constructed with a 20 slot screen from 21.3 mhls v:\01609\active\161110897_strange_st\planning\report\final hydrogeo assessment\final\fnl_rpt_120319.docx 4.3