Drinking water is an important necessity for all living beings and its safety is a vital aspect to be considered globally by all. It becomes even more crucial to ensure that potable water is clean and fit for human consumption in developing nations due to the ever-increasing pollution, on one hand, and the low social and economic conditions of the people living there. This chapter introduces this aspect of the book by presenting to the reader the availability and need of drinking water, efforts that are being taken to ensure safe drinking water for all worldwide by different water authorities and regulating bodies and the quality guidelines. Most importantly, various water pollutants such as chemical, physical, biological and emerging contaminants found in water are discussed with the associated health risks in humans. A brief outline of various water treatment methods and the objective of this book are also described to introduce the topic to the reader.