It would use mechanisms for identifying similarities among contaminants and contaminant classes to assess the potential risks of individual contaminants—especially emerging contaminants.
It would result in CCLs containing only contaminants that when regulated would reduce disease, disability, and death, and excluding contaminants that have few or no adverse effects on human health (e.g., contaminants removed or detoxified through conventional drinking water treatment methods).
However, EPA’s resources are still constrained; no comprehensive list of potential drinking water contaminants yet exists; and health effects, occurrence, and other related data for the vast majority of potential contaminants are poor or nonexistent (NRC, 1999b). Despite these limitations, the committee continues to recommend that EPA develop and use a two-step process for creating future CCLs as illustrated in Figure 1–3. In brief, a broad universe of potential drinking water contami-