Researchers from the University of Cincinnati conducted a study of all the tap waters in major cities across the country. They found that the tap water in St. Louis, which is the most dangerous city in the U.S., had some chemicals and pollutants but their amount was way below EPA standards. The water also had a better taste, scent, and clearness. St. Louis' two water purification plants draw water primarily from the Missouri river, and they produce 150 million gallons of clean water each day, according to the mayor’s office.