Perchlorate is not currently regulated by the U.S. Environmental Protection Agency. In 2005, EPA announced it had set a reference dose of 0.0007 mg/kg for perchlorate, following a recommendation from the National Academies of Science. This translates to a Drinking Water Equivalent Level of 24.5 ppb.
In 2011 the EPA made a final regulatory determination that perchlorate meets the Safe Drinking Water Act's criteria for regulating a contaminant and it intends to initiate a rulemaking process to develop a national primary drinking water regulation for perchlorate.
Several states have initiated regulatory reviews to prepare a drinking water standard for perchlorate. California and Massachusetts have set "public health goals" for the contaminant levels of 6ppb and 1ppb respectively.