Wondering what's in your water?

Have you ever wondered what's in your drinking water? With a recent high-profile series called Toxic Waters in the New York Times on the state of the nation's water supply, it's no surprise that at least one user of Ask Water, our online reference service, did.

Thankfully, when it comes to drinking water, there's a mandate of transparency. Water systems that serve the same population year-round, known as Community Water Systems, are required to file Consumer Confidence Reports (CCR) annually. Including basic data on contaminants, violations and their potential health effects, and other water-related educational information, CCRs are good places to start learning about what's in your water.

And they're convenient. Since Community Water Systems are required to make a good-faith effort to notify their users, they often arrive without even asking. Maybe you've found one in your mailbox.

But if you haven't, don't worry. A few online databases can also do the trick.

In Wisconsin, the Department of Natural Resources maintains the Drinking Water System, a database on water quality testing that includes links to CCRs. It can be searched by Public Water System, or other things, like specific contaminants.

Nationally, the EPA also has a number of databases, including the Safe Drinking Water Information System. It can be found at http://www.epa.gov/safewater/databases/index.html