Abstracts

Well data were also extracted from over 350 documents collected from municipalities and
government agencies. New fieldwork involved 11 cone penetration tests, 24 rotopercussion
soundings and 9 conventional wells open in the rock aquifer. Complete chemical analyses
were carried out on 131 groundwater samples, mostly collected from residential wells.
Almost 200 other chemical analyses were obtained from previous or on-going projects in
the study area.
Over a 10 to 30 km-wide strip adjacent to the St. Lawrence River, the topography is that
of a low plateau, which was covered by the Champlain Sea up to 180 m ASL, while the
interior of the region is either hilly or mountainous. Farmland occupies the St. Lawrence
valley and its main tributary valleys over about 22% of the region, while 60% of the region
is forested, and the remainder is either urban, wetlands or water bodies. A small area is
underlain by the geological province of the St. Lawrence Platform and the remainder is
part of the Appalachians. Fine-grained marine sediments are present below about 100
m ASL, while extensive sand blankets occur up to the Champlain Sea limit. The hilly
interior is covered by relatively thin and permeable till, with glaciofluvial sediments locally
present. The regional aquifer consists of fractured bedrock, whilst restricted local aquifers
are in surficial sediments. In terms of water use, 70% of the 287 000 residents relies on
groundwater through private wells or municipal water supply, as 64% of municipalities use
groundwater from more than 300 supply wells. Groundwater provides 40% of total water
use, 30% of this being used for industrial or commercial purposes, 38% residential and
32% agricultural. Although groundwater is generally of good quality, naturally occurring
components locally exceed provincial drinking water criteria (F, Ba and As). Seven water
types were defined on the basis of the proportions of major ions. Some of these water types
represent a natural geochemical evolution. However, other water types appear to indicate
groundwater quality degradation that could be due to agricultural activities, deicing salts or
waste water. While concentrations associated to these water types generally do not exceed
standards, mitigation measures should be taken to prevent further degradation.
251 - Regional hydrogeological mapping of saline and non-saline
groundwater resources in the Belly River Group of the Alberta
basin
Nevenka Nakevska, Amandeep Singh, & Dan Palombi
Alberta Geological Survey, AER, Edmonton, Alberta, Canada
Characterization of saline groundwater resources is becoming increasingly important as
the Government of Alberta implements its Water Conservation Policy seeking to minimize
freshwater use in the energy sector. The groundwater program at the Alberta Geological
Survey (part of the Alberta Energy Regulator) is re-initiating the mapping and
characterization of saline aquifers using existing methodologies and improving upon them
to account for variable-density groundwater.
Our current study is focused on the regional mapping of hydraulic heads, total dissolved
solids, and density-corrected flow directions in the Belly River Group. The Belly River
Group is one of the youngest (upper Cretaceous-aged) economically important hydrocar-
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