This article discusses a range of safety issues relating to drinking water. These include chemical safety, including lack of minerals and an excess of minerals; contaminants, those from environmental sources, such as heavy metals, pesticides, and other organic contaminants; and process contaminants, such as disinfection byproducts. Emerging issues are highlighted, especially with regard to the presence of endocrine disruptors and pharmaceuticals. The final section covers the microbial safety of drinking water and the main waterborne pathogens, including risk management and control.