A significant portion of groundwater exists within open fractures in bedrock aquifers. These aquifers tend to be much more complex than the basin-fill or alluvial aquifers where groundwater exists in pore spaces between clasts. Some fractured aquifers have a high enough degree of fracturing that flow characteristics are very similar to unconsolidated sedimentary aquifers. However, most fractured bedrock aquifers have limited fracturing intensity and direction that creates an anisotropic groundwater flow regime. Groundwater modeling of anisotropic fractured bedrock aquifers requires additional data to determine preferential flow direction and potential limiting factors for groundwater flow in the aquifer. GGI conducts geologic mapping and detailed fracture analyses to determine dominant fracture orientations controlling groundwater movement. In addition, we conduct long-term (96 hour to 14-day) pumping tests on production wells and monitor observation points to determine groundwater flow characteristics.
Spring emerging from fractures bedding planes in a sedimentary bedrock aquifer.