I read about an excerpt from a NY Times news article at SheBlogs about the possible growing amounts of atrazine (a herbicide) in tap water. I also checked out the Zuvo Water site, because the Zuvo Water Canteen was mentioned and I was interested in learning more. We actually use a small Brita filter, but it looks like the Zuvo stuff costs way less. Seems more and more there are concerns about our water systems but it's hard to stay informed. Check out Zuvo Water if you're interested too!