Vacuum Wellpoint Dewatering System at Mission Rock
Located on the sunny shores of the historic Mission Bay district, the Mission Rock Resort hired Malcolm Drilling to design a vacuum wellpoint dewatering system to minimize groundwater flows during the placement of lightweight concrete. The intent of the vacuum wellpoint dewatering system was to draw down and maintain the groundwater as close to the Bay Mud level until the new structural section achieved a weight to overcome the hydrostatic uplift forces. We utilized the sonic drill which allowed in situ soil samples to be taken during the well drilling. The samples provided the exact depth to which the Bay Mud was encountered so that the well screens could target that interface. Additionally, the well points were drilled at an angle to increase the screen’s surface area along the top of bay mud and minimize the distance between the dewatering and the subgrade excavation.