St. Louis Water (IMAGE)
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This is St. Louis water. "You might be surprised to know that the pH of St. Louis drinking water is 9 to 9.5," Giammar says, "much higher than the pH of distilled water, which is 7." In fact, it is heading toward milk-of-magnesia territory. He explains that the pH of the Missouri River is about 8, because the river flows through limestone, which makes the water somewhat alkaline. The limestone also makes the water hard, meaning it contains high levels of calcium and magnesium. So when it reaches the St. Louis water treatment plants, the pH is raised to between 10 and 11 to precipitate out some of the calcium carbonate and soften the water. The water utility then lets the pH drift back down to somewhere between 9 and 9.5 before the water is delivered. "It’s a nice stable water with good water chemistry," Giammar says."Quite non-corrosive, has a good stable pH. They do all right with their distribution system," he says. By the way, St. Louis water is disinfected with chloramines rather than chlorine.
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This image is in the public domain because it contains materials that originally came from the United States Geological Survey, an agency of the United States Department of Interior. For more information, see the official USGS copyright policy
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