The following is a list of the 6 groups of viruses which cause gastrenteritis. These have all been found and isolated in contaminated drinking water and beaches. Syptoms include acute vomiting and mild to severe dysentary.
Rotaviruses
Norwalk-like agents
Caliciviruses
Astroviruses
Small Round Structured Virus (SRSV)
Enteric Adenoviruses
Protazoa
The following is a list of the 3 main genera of waterborne protazoa that are harmful to humans. They exist independently of the host and are spread through fecal contact. Symptoms include dysentary, vomiting and anorexia.
Giardia
Entamoeba
Cryptospordium
Non Dysentary Diseases
This is a list of diseases that do not cause dysentary, but do pose a threat to humans and can be present in contaminated drinking water. Symptoms include lung, liver damage and Weil's disease.
Legionellosis
Leptospirosis
Hepatitis A
References
Jones, K, 1994. Waterborne Diseases, New Scientist, vol. 143, p4p.