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Groundwater Quality

The Alberta Centre for Toxicology has an active well-testing program. Groundwater samples from 1,258 wells were collected over the past decade and compared with Canadian Drinking Water Quality Guidelines. Of particular concern in the watershed are documented cases of arsenic concentrations above the Canadian Drinking Water Guideline.35 The table at right summarizes that information.

Two regions in particular face significant stress on groundwater quality, with little monitoring: The southern Smoky/Wapiti basin around Grande Cache and the area north of Wapiti River from Grande Prairie to Beaverlodge. Three active GOWN wells are in the area between Grande Prairie, Beaverlodge, Hythe and up to the Spirit River area. This region is underlain by a large natural gas reserve in the Montney geologic formation and has become a hot spot for both conventional hydrocarbon recovery as well as hydraulic fracturing. For example, Encana planned to expand operations to 80-85 wells in the Montney formations alone in 2014.

The area surrounding Grande Cache in the Southern Wapiti Basin has a history of coal mining. Studies highlight the effect of selenium levels on streams and fish populations in the region. The Upper Wapiti Formations (Horseshoe Canyon, Oldman, Foremost) underlying the region have low yields and poor water quality, making groundwater vulnerable to stress. There is no active monitoring well along the Smoky River. Water levels in some wells (for example, near La Crete) have significantly declined and do not currently show signs of recovery. These should be examined further.

Parameters No. of wells
exceeding guideline values
Guideline values
Maximum Acceptable Concentrations (MAC) Aesthetics Objective MAC
Aesthetics Objective (mg/L)
Chloride   20   250
Fluoride 249   1.5  
NItrate 6 27 45 3.2
pH   637   6.5-8.5
Sodium   1005   200
Sulphate   118   500
TDS   1125   500
Trade Metals
Antimony 2 0.006    
Arsenic 4 0.01    
Barium 0 1    
Boron 0 5    
Cadmium 0 0.005    
Lead 4 0.01    
Mercury 0 0.001    
Selenium 0 0.10    

Alberta Health and Wellness. 2000. Arsenic in groundwater from domestic wells in three areas of Northern Alberta. Edmonton, AB