Geochemistry of groundwater from bedrock underlying the Fredericton aquifer

Abstract

Evidence suggests that there is groundwater flow between the Fredericton aquifer and the underlying bedrock. This project determined the geochemical characteristics of the bedrock water, assessed seasonal changes that may occur in the bedrock groundwater system and attempted to determine the fraction of bedrock water that contributes to the Fredericton well field. Bedrock wells that surround the Fredericton aquifer were sampled from January 2002 until August 2002. Results show that the bedrock water is variable between Ca-Na-Cl-S04 type and Na-Ca-Cl-S04 type water and that the mean manganese levels are above the Canadian Drinking Water Guidelines. Seasonal changes were not observed in the bedrock groundwater except for at one well located on Tamarack Terrace where Cl concentrations indicated an influence from road salt. The fraction of bedrock water contributing to the Fredericton well field could not be determined from major ion data alone.