Anytime....and I encourage you and others to register your info and time-frames of exposure to the drinking water. They'll have all kinds of questions, so try to be as accurate as possible and get back to them later if you remember more. Tell them what you know/where you were located/housed, how often you used the water and for what purposes, etc. It will make their studies more accurate, to help you and others in the future. As with most of these situations, some people are very sensitive to exposures, while others are not - everyone's different, so don't assume you're bound to get cancer - you may never. So call your old buddies and catch up on old times and tell them to register, for the good of the many. Hang in there, but don't sweat it yet.