The following is a brief list of the different contaminants and additives found in municipal water supplies that may cause or contribute to problems in environmental illness sufferers:

Although most of the harmful substances often present in water sources are removed by the water companies, significant amounts of harmful substances remain in the water when they come out of your faucet.In a review of US federal and state records in 2004/2005 carried out by the Environmental Working Group (EWG) as many as 45 million Americans were found to be receiving water that fails basic health standards. Their review found that over 25 million people used water contaminated by bacteria, 5 million had lead levels above standard and inadequate water treatment was a problem for 20 million water customers. In another EWG study that focused on agricultural states it was found that 14 million people were consuming tap water routinely contaminated with five major herbicides.

This situation is not unique to the United States but rather is common in western countries.