Which diseases are caused by microbes found in untreated surface water?

Untreated surface water can harbor a variety of harmful microbes, leading to diseases such as gastroenteritis, cholera, and dysentery, primarily caused by bacteria like E. coli and Vibrio cholerae. Viruses such as norovirus and hepatitis A can also be present, causing gastrointestinal and liver infections. Additionally, protozoan parasites like Giardia and Cryptosporidium can lead to severe intestinal illnesses. Consuming or coming into contact with contaminated water can pose significant health risks.