In Spring 2012, The United States Environmental Protection Agency, Office of Water, published the 2012 Edition of Drinking Water Standards and Health Advisories. The Drinking Water Standards and Health Advisories tables are revised periodically by the Office of Water so that the benchmark values are consistent with the most current Agency assessments. Reference dose values are updated to reflect the values in the Integrated Risk Information System and the Office of Pesticide Programs Reregistration Eligibility Decisions documents. The associated Drinking Water Equivalent Level is recalculated accordingly. The 2012 Edition of the Drinking Water Standards and Health Advisories  can be downloaded from:

http://water.epa.gov/action/advisories/drinking/upload/dwstandards2012.pdf