Sam Ziemann From - Region of Waterloo

HYDROGEOLOGICAL ASSESSMENTSTRANGE STREET WATER SUPPLY CLASS EA UPDATEREGIONAL MUNICIPALITY OF WATERLOO4.0 Results for Test Well4.1 TEST WELL DRILLING LOCATIONSIn 2010, Stantec completed a background review and identified two (2) preferred test drillinglocations, Gzowski Park (TW3) and the Westmount Golf and Country Club (TW4) (Figure 6).The preferred test drilling locations were identified using a number of criteria including, potentialwell capacity, thickness of the target aquifer, potential water quality threats, proximity to existingwater supply infrastructure, and site access. Results of the test site selection were documentedin Technical Memorandum A2 (Appendix E).Both preferred test drilling locations scored high on water quantity and ease of connection to theexisting infrastructure, with a moderate score for water quality due to select parameterselevated above the ODWS which would be dealt with through the implementation of anupgraded treatment system.Based on the results of Technical Memorandum A2 (Appendix E), one (1) 127 mm diameter testwell, TW1-11 (Figure 1) was constructed and tested at preferred drilling location Gzowski Park.There was no additional test well installation completed at the second preferred drilling location,Westmount Golf and Country Club, due to issues with Site access.It should be noted that preferred test well drilling location Knell Drive (Between K11A and K13)scored highest based on the criterion and was previously identified in the initial Class EA as apreferred test drilling location. However, with the recent construction of K11A, and futurepotential rehabilitation/replacement of K13, installing a third production well in this area toprovide firm water capacity was no longer warranted.4.2 GEOLOGYIn support of construction of Test Well K-SS-TW1-11, an initial borehole was advanced to thetop of bedrock (81.9 m BGS) using continuous coring techniques. The initial pilot hole wasdrilled to the top of bedrock so that the entire overburden sequence could be evaluated. Thisapproach also addressed the data gap identified in the Tier 3 Water Budget and Water QuantityRisk Assessment (Stantec, 2009) that additional high quality deep overburden data was neededin the Strange Street Well Field area. The initial borehole was completed as monitoringwell K-SS-OW1A-11. The interpreted log for K-SS-OW1A-11 is included in Appendix G. Thefollowing is a summary of the geology encountered:AFB1 (Aquifer 1):A surficial layer of topsoil, underlain by clayey silt and sand to344.12 m AMSL (1.12 m BGS) was encountered and was likely surficialfill associated with the construction of Gzowski Park.Deposits of typically fine to silty sand were encountered in the upperportion of Aquifer 1 (AFB1), extending from 344.1 m AMSL (1.12 m BGS)hls v:\01609\active\161110897_strange_st\planning\report\final hydrogeo assessment\final\fnl_rpt_120319.docx 4.1