What is one reason for why the availability of drinkable water in the developing world is a problem?

When people don't have clean water or access to clean drinkable water it can result in many diseases and health issues such as Amoebiasis, Bacillary dysentery, cholera and crytosporidiosis

Without clean drinking water, it leads to a number of health issues. Many diseases are waterborne which means they start off in the water, and are ingested through drinking that water. One example of such a disease is cholera.