Arizonans are in no danger from drinking water- or are they?

How can we be sure when Arizona allows the highest levels of perchlorate cited in this article? We allow 14 ppb compared to New Mexico (where two national labs and a missile range are located) which only allows for 1 ppb. Keep in mind that there is continuing debate on what a safe level is. The EPA has yet to set standards for Perchlorate, but the current working level from their 2002 draft is 1 ppb. Studies that are more recent suggest that that may be too high, but the EPA is not expected to make a final recommendation until 2006. Shouldn't we err on the side of caution? Environmental groups think so, EWG is calling for a standard of 0.1 ppb and they make a convincing case based on an FDA study.