ABSTRACT
There is 50 times more groundwater within the planet than on its surface in rivers, lakes and other surface water bodies (NWC, 2012). Regarding water supply, groundwater is usually favoured over surface water when both are an option. This is because groundwater is often close to the area it supplies (usually directly underneath it), is well protected from surface contamination and thus needs minimum treatment to achieve high quality, and is less susceptible than surface water to drought and other climate-induced variability. It is also because of the nature of investments in groundwater development: if planned properly, groundwater infrastructure investments can be made more gradually than those for surface water; this allows for growing private, municipal and industrial demand to occur with lower investment and operation costs (Howard and Gelo, 2003). Groundwater is also more evenly distributed in aquifers over large regions. Therefore, it is not surprising that many of the most populous cities in the world, including some in Latin America, attribute their early origins and development to good quality groundwater obtained from shallow wells (Zektser and Everett, 2004).
