As part of its Toxic Waters series, the New York Times has posted Environmental Working Group contaminant data for lots of public water systems. A lot of places post this data online for the public. But as someone who’s sifted through these kinds of records many times for stories on water issues, I can tell you they’re tough to translate — so this is a major public service.
The upshot is that American drinking water standards are outdated, and millions of people’s tap water is legal but still unhealthy. Here’s the NYT’s full page on Madison; or, if you live somewhere else, search for your water data here.
Madison’s water system hasn’t gotten any EPA violations since 2002. It has no contamination that exceeds EPA drinking-water standards. But tests have found four contaminants since 2004 that are within legal limits but are still unhealthy.
• Radioactive elements radium-226 and radium-228. Found over health limits in 2004 tests but not since. All sorts of potential health effects from chronic overexposure; EPA calls it a “potent carcinogen.”
• Manganese, naturally occurring, also used industrially. Two tests in 2004 were way over the health limit, though most tests were below it. An essential nutrient at low doses, but may be harmful at higher ones. EPA says data is spotty on just what these health effects from oral ingestion might be, but it could cause neurological effects (pdf source).
If you’re competitive about this sort of thing, check out EWG’s lists of the best and worst city water supplies.
Of course, you have to assume that anyone who’s willing to eat the fish from lakes Monona and Mendota, especially the walleye, already has a devil-may-care attitude toward ingesting pollutants. But I prefer to know the risks and make a conscious choice, don’t you?
Incidentally, my PUR filter’s tech specs say it basically gets tetrachloroethylene from 15 parts per billion down to 0.5 ppb — if you change the filter, which I haven’t done since I moved here.