Drinking water Technology, Eawag, developed a method by which hazard maps could be produced for geogenic toxic substances in groundwater. This provides an efficient way of determining which wells should be tested. Parameters for drinking water quality typically fall within three categories: Physical and chemical parameters include heavy metals, trace organic compounds, total suspended solids (TSS), and turbidity. Microbiological parameters include Coliform bacteria, "E. coli", and specific pathogenic species of bacteria (such as cholera-causing "Vibrio cholerae"), viruses, and protozoan parasites. Chemical parameters tend to pose more of a chronic health risk through buildup of heavy metals although some components like nitrates/nitrites and
Drinking water region have access to proper means of sanitation. More than 2,000 children's lives are lost every day. In South Asia, 683,000 children under five years old died each year from diarrheal disease from 2000 to 2003. During the same period, in developed countries, 700 children under five years old died from diarrheal disease. Improved water supply reduces diarrhea morbidity by 25% and improvements in drinking water through proper storage in the home and chlorination reduces diarrhea episodes by 39%. Some efforts at increasing the availability of safe drinking water have been disastrous. When the 1980s were declared the "International Decade