One of the first steps in the consideration of a GSHP system is a characterization of the site in terms of geology and groundwater availability. Information concerning aquifer (or aquifers) available at the site, their ability to produce water, depth to water, geology, depth to bedrock and the nature of the soil and rock (hydraulic and thermal properties) are key issues. This information guides the designer in the selection of the type of GSHP system to be used and in the design of the system