I have seen these same regulations as well as studies for chlorination of drinking water http://www.edstrom.com/DocLib/MI4174.pdf. There is evidence that levels up to 10 ppm are safe to drink (in lab mice at least) and there is 0ppm of CYA. Seems to me, common sense steps in and if you can safely drink up to 10, you are probably safe to swim in much, much higher chlorine levels.