In a November 24 letter to EPA Administrator Gina McCarthy, the Natural Resources Defense Council (NRDC) gave notice of its intent to sue over the missed statutory deadline for the proposal of a perchlorate drinking water standard. A positive regulatory determination for perchlorate was made in February 2011 by previous EPA Administrator Lisa Jackson, which triggered the Safe Drinking Water Act (SDWA) statutory requirement for EPA to propose a maximum contaminant level goal (MCLG) for perchlorate within two years.
Pledging to “get the science right,” EPA managers have been clear that the agency was going to miss the 2013 SDWA statutory deadline for a perchlorate proposal after its Science Advisory Board (SAB) recommended the use of updated scientific models to determine the proper level at which to set the MCLG. Since then, EPA has been working with the Food and Drug Administration to develop a dynamic model that would incorporate the latest science on the uptake and health effects of perchlorate for different segments of the population, information that is key to the development of an accurate MCLG. Given the complexity of such a modeling effort and associated peer reviews necessary to validate its findings, EPA’s current schedule for proposal of the perchlorate standard has been pushed to early 2017.
In light of the direction from the SAB and EPA’s overall commitment to robust scientific analysis, it is unclear how the NRDC lawsuit will ultimately influence EPA’s regulatory development timeline for a perchlorate drinking water standard. It is an issue that bears further watching when the actual lawsuit is filed in 2016 and, potentially, plays out in the courts.