The water news popping up in my email inbox recently has really run the gamut. One of the latest health fads is apparently drinking "raw water"—meaning unprocessed and untreated water. At the other end of the spectrum, there are a couple of new proposals to drink "poop water"—water produced by thoroughly treating sewage effluent to meet drinking water standards.

First, a look at raw water. The New York Times, The Washington Post, the BBC, and even The Oregonian have featured stories about the raw water craze. One of the sources of this hot new product is here in the Northwest—Opal Spring, in Central Oregon—the source of the Crooked River. Lots of people in Central Oregon have been drinking that same water for years, paying less than one cent a gallon, because it just happens to be the source tapped by their local drinking water suppliers. But now, a clever entrepreneur is bottling the spring water without any treatment or filtration and selling it directly to consumers in California—at a price that is a thousand times higher than those Oregon water bills. The supposed attraction is that since the water is unfiltered, it contains helpful probiotics that would otherwise be removed, and since it is untreated, it doesn't contain any harmful chemicals or other added substances.

Pure, clean, unfiltered spring water is great—assuming that is in fact what you're getting. But just because water comes straight out of the ground does not automatically mean it is safe. Safety depends on how long the water has been underground and whether the groundwater itself is affected by any toxins or contaminants—unnatural, like pesticides, or natural, like radon or arsenic—and on whether animals visit the spring when the entrepreneurs aren't around.

The general notion that raw water is better than treated water is a pretty unhealthy premise on which to base a health fad, so you may want to let the raw water craze pass you by.