Earth Sciences Report 1975-06

Earth Sciences Report 1975-06

ESR 1975-06

Regional Chemistry of Groundwater in the Wainwright Area, Alberta

Author(s) Hackbarth, D.A. Date 1975-01-01

The Wainwright map area is located southeast of Edmonton between longitudes 110 & #176; and 112 degrees west and latitudes 52 degrees and 53 degrees north. It covers about 6,000 square miles (15,500 square km), lying mostly in the aspen parkland vegetational assemblage. Average precipitation is about 14 inches (36 cm) annually, while potential evapotranspiration is about 21 inches (54 cm) annually.

Geological units of hydrogeological interest include glacial drift, preglacial sands and gravels, Horseshoe Canyon Formation, Bearpaw Formation, Belly River Formation and Lea Park Formation.

Contour maps of the following hydrochemical parameters for various depth intervals are presented: 1)total dissolved solids, 2)hardness, 3)sodium plus potassium, 4)alkalinity, 5)sulfate, 6)chloride and 7)fluoride.

Groundwater quality is related to the thickness and nature of the glacial drift and to the character of the underlying bedrock. Areas where the water quality is comparatively good for depths up to 500 feet (152 m) are usually overlain by 50 to 400 feet (15 to 122m) of coarse-grained glacial drift. Rapid movement of water downward is hypothesized to account for this good quality. Groundwater of poorer quality is commonly found in areas of thin, fine-grained drift and is apparently the result of slow downward movement of water. The marine Bearpaw Formation accentuates this situation.

Considered regionally, the area acts as a recharge for groundwater flowing to the northwest. However, much water is probably discharged locally in sloughs.

Hackbarth, D.A. (1975): Regional chemistry of groundwater in the Wainwright area, Alberta; Alberta Research Council, ARC/AGS Earth Sciences Report 1975-06, 52 p.