Perchlorate Peer Review Panel Report Released

In January EPA convened a public peer review panel to review how EPA could apply a Biologically Based Dose-Response (BBDR) model to deriving the Maximum Contaminant Level Goal (MCLG) for perchlorate.  The report from this peer review process is now available on EPA’s Docket.   This new modeling based process for developing the MCLG is the result of a recommendation from EPA’s Science Advisory Board (SAB).  The SAB believes this approach is superior to the traditional reference dose approach but it has been a lengthy process and caused EPA to miss regulatory development deadlines.

In the report, the reviewers recognized the extensive work EPA has done to create “a highly innovative state-of-the-science set of quantitative tools to evaluate neurodevelopmental effects that could arise from drinking water exposure to perchlorate”.   Generally, the reviewers agreed that the models, with a few tweaks, were a reasonable basis for developing the MCLG.  They agreed that a focus on the early gestation period of the fetus was appropriate but that other life stages also needed to be considered in developing the MCLG.  The panel also had recommendations on additional studies and some reevaluation of existing studies used to support the process.  The reviewers suggested adjustments to the model at various points that would improve the outcome.  Specific answers to a long list of charge questions are included in the report.

EPA will take all the information from the peer review process, and any additional comments provided through the docket, into consideration as they develop the MCLG and subsequently the MCL.  Additional information on this process is available on EPA’s perchlorate web page.