md, I have had you on ignore, so I only became aware that you were requesting a source when evaheisel replied. Thanks to Eva, you now have your source. But I think it is amazingly arrogant for you to ask. You have made so many statements on this board that are false, with never a case, that I have seen, when you retracted a false claim. And your idea of a source is usually untrustworthy.
The EPA considers water unsafe to drink if it has three parts per billion of atrazine, but the comparable limit for glyphosate is 700 parts per billion. By this measure, glyphosate is 230 times less toxic than atrazine.
My apology, Eva. When I looked, a number of years ago, at the EPA regulations for both herbicides in drinking water, the maximum allowed for atrazine was 2 ppb. I'm not sure when or why it was raised to 3 ppb.
I hope everyone realizes that even if atrazine is ONLY 230 times as toxic as glyphosate, that's still a huge difference and nobody should fail to understand that replacing Roundup-ready corn with conventional corn is an environmental setback.