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
Water supply and sanitation in Mali a percentage that is incredibly high at 45% in some cases. It showed that improved hygiene was twice as effective at reducing waterborne diseases than improved drinking water sources. Improved water drinking sources was not as successful due to recontamination that may occur in a household, which can happen through situations such as water handling or the way water is stored. A common issue that occurs in Mali is open defecation. Over half of the people that do not have access to safe water live in rural areas. Diseases can easily be spread when fecal matter contaminates water sources, such