AWWA JAW70702

To supplement the processes used for developing the draft third Contaminant Candidate List (CCL3) and better inform decisions made by the US Environmental Protection Agency on future CCLs, the authors offer an evaluation tool for efficiently synthesizing, visualizing, and organizing data for effective comparisons among contaminants. Graphical presentations of health effects-occurrence indexes were developed for more than 300 chemical contaminants, including those on the draft CCL3. A risk indexes framework was then used to elucidate the extent of available data, the data quality, and the underlying uncertainties for occurrence and toxicity. Choosing the appropriate contaminant for regulation is a complex process that cannot be totally automated; expert judgment will always be needed at some point in the process. However, the framework and recommendations presented here could help facilitate the process and provide direction for research funding. In addition, water suppliers could use a similar process to assess emerging contaminants in their watershed and make appropriate treatment decisions. Includes 21 references, tables, figures.