The physical and geochemical characterization of oxygen-depleted breathing wells in Central Alberta

This thesis presents the results of an investigation on oxygen-depleted breathing water wells in central Alberta. Four breathing wells were monitored to determine the connection between barometric pressure fluctuations and the changing gas compositions within these wells, and to determine the potential causes for the depletion of oxygen in these wells.; Results indicate that changes in oxygen concentrations are positively correlated with pressure fluctuations. Geochemical analyses verified that the groundwater is deficient in oxygen and elevated in nitrogen gas. Nitrogen gas is produced by denitrification. These data suggest that some of the oxygen that reaches the variably saturated aquifer is partially consumed by organic and inorganic reactions. During exhaling periods, excess nitrogen gas exsolves from the groundwater and dilutes the remaining oxygen in the unsaturated zone. These results highlight the risks associated with such wells, and emphasize the need for proper well completions in areas prone to such behavior.