Distribution of Total Dissolved Solids in the Paskapoo Hydrostratigraphic Unit

This map depicts the distribution of total dissolved solids (TDS) in groundwater in the Paskapoo hydrostratigraphic unit (HSU). The map is a result of Empirical Bayesian kriging technique using publicly available water chemistry data from the Alberta Government's Alberta Water Well Information Database (AWWID) and a previous Alberta Geological Survey water sampling project reported in AGS Special Report 81.

The TDS distribution was mapped at a regional scale using many years of data, thus providing a good indication of regional water chemistry within the HSU rather than site specific values. The uncertainty of prediction is depicted on an inset map, which shows the residual values (modelled value minus measured value) plotted at each location to indicate where underprediction or overprediction occurs. Two additional inset maps show the distribution of hydraulic heads, and depth to and vertical thickness of the Paskapoo HSU. The geometry and variable thickness of the Paskapoo HSU are illustrated on schematic cross-sections.