1. Introduction

There is variable definition for groundwater. Agronomists define groundwater as any water below the ground. For engineers groundwater is often termed as subsurface water and occurs below the ground. For hydrogeologists groundwater is water in the saturated zone. A number of other names are attributed to groundwater. This include: sub surface water, under groundwater and groundwater. Rocks in which groundwater occur are also named differently. Aquifer is a rock that holds and transmits water at an economical rate. Aquiclude is a rock that doesn’t hold or transmit water at economical rate. Aquitard is a rock that holds water but doesn’t transmit the water to wells at economical rates. Groundwater exists inside fractures of rocks or inside open spaces called porosities of rocks. Open spaces are formed either after or during the formation of the rocks themselves.