Because of its extremely low concentrations and strong resistance to most treatment technologies, perchlorate has become one of the biggest challenges currently being faced by the drinking water industry. Although significant research has been performed to evaluate different treatment technologies for perchlorate removal from drinking water, there has not been a holistic review performed recently. A complete and critical review on the intriguing contaminant 'perchlorate' is presented. The sources of perchlorate along with the degree of contamination are discussed. The policy aspects including the regulation and toxicity in addition to the most recent developments in perchlorate analysis are also considered. The applicable treatment technologies including their feasibility are discussed in detail. Although some technologies such as microbial reduction and ion-exchange have become more established than the others, there is still not a single technology that can be directly applied to a drinking water treatment system for compete removal of perchlorate. Although significant research is still being conducted to come up with a novel technology for perchlorate remediation, it is highly likely that it would not be a single novice or conventional technology but a combination of these technologies that would have to be employed to overcome this challenge. (c) 2009 Elsevier B.V. All rights reserved