Modelling the Groundwater Flow of the Carbonate Aquifer during Pump Tests of Two Wells in East St. Paul, Manitoba

ABSTRACT: The upper carbonate aquifer is a highly fractured limestone formation that is the main supply of drinking water for the Rural Municipality of East St. Paul, Manitoba. There have been several pump tests conducted in the region to determine the capacity of wells drilled into the aquifer. A 3D numerical model was developed using commercially available finite element software to simulate groundwater flow during two pump tests in the East St. Paul region. Four numerical approaches were used to model the pump tests in the fractured aquifer: 1) continuum, 2) minor fracture network, 3) major fracture network, and 4) major fracture network coupled with continuum. The size of study area, material properties, and fracture network density were modified in simulations to understand how they impacted drawdown in the wells. The numerical modelling in this paper provided meaningful conclusions that should be built upon in future studies to model groundwater flow in the East St. Paul region.