At the DFC homestead, we use well water. This was a significant difference from the city supply we were used to before we moved here and a change that gave us pause initially. Even though I’m a trained chemist, I couldn’t help my citified brain briefly piping up: “But if it came out of the ground, it’s not clean. Where’s the chlorine, where’s the fluoride that I know and love?”
This is, of course, nonsense: a well-placed, carefully maintained well that is up to provincial standards is a perfectly healthy way of getting water. In fact, research is showing that well water may, in some ways, be healthier than municipal water. City water is often sourced from open rivers or lakes and requires major chemical intervention with biocides in order to be made drinkable. In contrast, well water is sourced from aquifers that are deep underground; the water in them has not only been naturally filtered through soil, gravel, and rock but is effectively sealed off from surface contaminants and pathogens.
The Atlantic has excerpted a chapter about this from the new book, Never Home Alone: From Microbes to Millipedes, Camel Crickets, and Honeybees, the Natural History of Where We Live, by biologist and ecologist Rob Dunn. Dunn looks at respiratory illnesses that stem from the presence of the genus Mycobacterium and their biofilms in home water pipes — essentially colonies of bacteria and the “gunk” they produce to prevent themselves from being washed away. Mycobacteria are particularly present in showerheads. Many types are benign, especially if they stay on your skin, and your immune system is operational. But if not, some can get in your lungs and make you sick. Writes Dunn:
“When we examined our data, we found that the concentration of chlorine in the tap water from homes using municipal water in the United States was 15 times higher than that of homes with well water. Mycobacteria were twice as common in municipal water as in well water. In some showerheads from municipal water systems, 90 percent of the bacteria were one or another species of Mycobacterium. In contrast, many of the showerheads from houses with well water had no Mycobacterium. Instead, those biofilms tended to have a high biodiversity of other kinds of bacteria.”
As we were pondering these results, Caitlin Proctor at the Swiss Federal Institute of Aquatic Science and Technology published a new study very much in line with what we were finding. Proctor and her colleagues compared the biofilms of the hoses that lead into showerheads from 76 homes around the world. They found that samples from cities that did not disinfect their water tended to be thicker (more gunk), but samples from those that did disinfect their water were more likely to be lower in diversity and more dominated by mycobacteria.”
It seems that the inside of our showerheads is beset, like the world outside, bysuperbugs of sorts: bacteria or other critters that get meaner and stronger the more trials we throw their way. Though it might mean trouble for our society at large, it makes me feel better about using our well water personally. I’m reminded that there’s such a thing as too clean — and just because we’re multi-celled, it doesn’t mean we’re in charge!