Groundwater is water which is located beneath the Earth’s surface. This water resides in the soil pores and in the fractures of rock formations. A unit of rock which can yield a usable quantity of water is called an aquifer. The depth at which a soil pore fractures and becomes a void in the rock which is completely saturated with water is called the water table. Groundwater will recharge once used from the springs and wetlands. Groundwater is often used as our drinking water, for agricultural purposes and for industrial purposes. It is extracted from an aquifer through wells. Groundwater was traditionally thought of as liquid water flowing through shallow aquifers. Although this is true, it can also include soil moisture, permafrost, immobile water in low permeability bedrock and deep geothermal water. Hypothetically, groundwater is thought of as the lubrication which allows the earth to move through faults. Groundwater is being utilized all around the world. It is a renewable resource until it is over-used or as it’s called overdrafting. Putting groundwater into overdraft can have devastating effects. It can lower the water table and therefor cause the wells to have to be drilled deeper. Many ecosystems rely heavily on groundwater to provide a habitat. Groundwater is also susceptible to pollutants. When pollutants are on the ground, they can make their way down to the groundwater. This can contaminate the aquifer and in some cases make it completely unusable. The interaction of groundwater contaminates with surface waters is studied using hydrology transport models. Title Image Credit: Wikimedia Commons