The picture on the left is water traveling down the outside of de-watering pipe in a hard rock mine. The picture on the right is after the annulus of the pipe was injected with polyurethane grout to control the unwanted groundwater infiltration. This high-pressure injection of grout was able to stop the water in about fifteen minutes. The polyurethane grout used was SealGuard II, dual component material that reacts in 1-3 seconds to create a rigid foam. SealGuard II is manufactured by SealGuard, Inc. and the injection was performed by Sub-Technical, Inc.