Water & Sanitation

The 'Key Themes' posts are a series of short articles outlining the role that geologists have in various aspects of global development.

An important global sustainability challenge is ensuring access to clean water and good sanitation to all. Current estimates suggest that nearly 663 million people lack access to clean water, and 2.4 billion people lack access to good sanitation (Water.org).

Water is essential for life. Where communities don’t have access to clean water they are forced to drink dirty and dangerous water. This water can cause serious illness, sometimes leading to death. Many communities have to walk several kilometres to collect their water. In some cases this water is clean, in other cases it is unsafe but the closest or only water source around.

Lack of access to clean water also has a direct impact on many other areas of development. Usually it is women or children who collect the water, meaning children miss school and lose out on their education. The longer women spend collecting water, the more they lose out on income-generating activities. Women make themselves vulnerable by walking to often-isolated places alone. Lack of access to sanitation can lead to girls dropping out of school, significant health affects and greater exposure to violence.

What role do geologists have to play in this sector?

Geologists play a crucial role in the identification and sustainable management of clean water supplies through the study and application of hydrogeology.

Hydrogeology is the study of the distribution and movement of water below the surface of the earth. Groundwater is often preferred to surface water as it has a greater protection from contamination that can occur on the surface. As water percolates through soil and rock, it is filtered to remove contaminants. Water is also protected from the high surface temperatures and subsequent evaporation that is common in many locations subject to water scarcity.   

Most groundwater is derived from rainfall, with some also coming from surface water features such as rivers and lakes. Rainfall infiltrates the ground and percolates through soil and rock to form underground stores of water in a particular rock/soil unit (known as an aquifer). Geologists have an essential role in locating these aquifers, determining how much water is in them, whether the water is safe to use, and how water can be sustainably extracted for use.

Understanding the geology of an area can help indicate where water resources might be located, where to drill for water, and how deep to drill. Geophysical techniques can also be deployed to provide additional information, making a significant difference to the successful drilling of boreholes in many locations.

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