| Summary: | The Apex River Watershed in Iqaluit, NU, provides a source of drinking water and recreational use for many local community members. However, the last published study concerning the catchment was in 1986. (Obradovic & Sklash, 1986) The preliminary research conducted by researchers in the Department of Geography in 2013 indicates abnormalities in the stable isotope concentrations of samples collected at confluence of the west and east tributaries from mid to late summer. The composition of the confluence water isotopes cannot be explained by simple mixing of the up valley tributaries, and is hypothesized to indicate the existence of groundwater sourced from melting ground ice. This study is evaluating the river water chemistry for the 2015 summer season. Samples were collected biweekly from four transects at the confluence, as well as weekly bulk water collection from the tributaries, confluence, and near the river outlet. Testing for high ion concentrations helps indicate subsurface flow, as subsurface rock weathering will provide a greater source of mineral ions than atmospherically deposited water at the surface. Based on preliminary results, there is a greater relative abundance of ions such as Cl, NO2, SO4, NO3, Na, and K observed at the confluence transects than at the other river sample sites. Since these ions originate from mineral weathering and salt dissolution, their abundance at the confluence supports the theory of increased melted groundwater inputs at this location as the season progresses. Further analysis will include a characterization of stable isotope values for the summer season to assist in differentiating between surface and ground water sources.
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