AWWA JAW61544

This article discusses how the recent firming-up of perchlorate risk science and occurrence data has gone a long way toward meeting two critical information needs for possible federal regulation. However, the article points out that the progress has fallen short of addressing the lingering uncertainties faced by water suppliers about how to respond to the high-profile contaminant. The remainder of the article reviews recent developments in U.S. Environmental Protection Agency and state efforts to characterize perchlorate risk and occurrence.