WSA Vanscoy

Observation well WSA Vanscoy was constructed in 1966 to a depth of 88.7 metres into Empress Group sands of the Tyner Valley aquifer. It was originally constructed as part of a study of the Tyner Valley Aquifer system and was subsequently incorporated into the observation well network that same year. The Tyner Valley aquifer in the vicinity of Vanscoy receives recharge from downward groundwater inflow and laterally from the adjacent bedrock Judith River formation. The direction of the groundwater flow is northward where there is some discharge from the Tyner Valley aquifer into the overlying Tessier aquifer.

The hydrograph for WSA Vanscoy shows influence from pumping in 1967/68 by the Agrium (then Cominco) potash mine. Following that, water levels fluctuated between 507 and just over 508 metres until 2003 when large scale pumping for construction of a nearby natural gas storage cavern began. This pumping lasted until 2007 and its impact on the hydrograph is very obvious with over 13 metres of drawdown occurring. About 2 metres of residual drawdown now remain in the well. The slow recovery following the 2003-2007 pumping indicates that the rate of recharge to the aquifer is very low.

WSA Vanscoy yields water of the sodium-sulphate type and has a sum of ions concentration of approximately 2280 mg/L. The water’s high chloride level (266 mg/L) is indicative of the influence of bedrock water as well.