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
Lead contamination in Washington, D.C. drinking water Lead contamination in Washington, D.C. drinking water Lead contamination in Washington, D.C. drinking water, first discovered in 2001, left thousands of children with lifelong health risks, and led to a re-evaluation of the use of chloramine in public drinking-water systems. Professor Marc Edwards, an expert in plumbing corrosion, discovered lead levels at least 83 times higher than the accepted safe limit while performing research into premature pipe corrosion for the District of Columbia Water and Sewer Authority (WASA). He found that the decision to change from chlorine to chloramine as a treatment chemical had caused the spike in lead levels.