Memo - 1.0 BACKGROUND 2.0 GROUNDWATER MONITORING NETWORK

2.2 WETLAND PIEZOMETERS To better understand the pre-development hydroperiod for the portion of Torrance Creek Swamp that directly lies to the southwest of the Site, Stantec established a transect of three drive-point piezometers downgradient of the future outlet of the proposed stormwater management facility (SWMF) (i.e., DP101-22 to DP103-22) (Figure 4). [...] These drive-point piezometers are designed to track the hydroperiod of the wetland following construction of the SWMF to assist in evaluating whether post-development stormwater discharge to the wetland could affect the long-term form and function of the wetland ecosystem. [...] Located approximately five kilometres to the northwest of the Site, the assumption is that the monthly average precipitation and air temperatures recorded at the station is reflective of the precipitation and air temperature fluctuation trends that have historically occurred at the Site. [...] The top of stone for the gallery is located at an elevation of 334.80 m AMSL, the elevation of the overflow pipe to the wetland, allowing the trench to become fully utilized before flowing downstream. [...] The EOP infiltration gallery achieves 0.66 m of separation from the seasonal high groundwater level during the early spring (i.e., March), but proceeds to achieve the one meter of separation over the remainder of the year.