What did the National Academy of Sciences (NAS) recommend for creating future CCLs?
The 2001 NAS report proposed a broader, more comprehensive screening process to assist EPA in identifying those contaminants for the CCL. The NAS recommended that we identify a broadly defined “universe” of potential drinking water contaminants, then assess and reduce the universe to a preliminary CCL (PCCL) using simple screening criteria that indicate public health risk and the likelihood of occurrence in drinking water. NAS recommended that EPA assess the PCCL contaminants in more detail using a classification approach and expert judgment to evaluate the likelihood that specific contaminants could occur in drinking water at levels of public health concern, and which should be on the CCL.
