ABSTRACT
The growing number of groundwater contamination sites where 1,4-dioxane is present leads to several important policy questions on the regulation of 1,4-dioxane in drinking water and at cleanup sites, as the preceding chapters demonstrate. Foremost among these questions is whether other states and the federal government should follow the lead set by the CDPHE and establish regulatory standards for 1,4-dioxane. The question of setting standards depends on the ongoing debate about 1,4-dioxane’s toxicity, which centers on the nonlinear dose-response for 1,4-dioxane’s toxicity and carcinogenicity endpoints. Do the toxicological assays of 1,4-dioxane adequately determine carcinogenicity? In the face of toxicological uncertainty, should we apply the precautionary principle and regulate 1,4-dioxane in case it is later confi rmed to be a human carcinogen? Or should we be cautious about committing scarce fi nancial resources to remediate contamination whose potential to cause harm is still being evaluated? Among the criteria used to set drinking water standards is the estimated population exposed to 1,4-dioxane in drinking water, which requires solid data for 1,4-dioxane occurrence in public drinking water systems. This in turn leads to questions on the policies applied by federal and state agencies to administer drinking water testing requirements that best serve the public for emerging contaminants such as 1,4-dioxane. When water utilities discover 1,4-dioxane in drinking water systems, they face the diffi cult challenge of risk communication, that is to inform their customers while preserving their reputation for reliably serving high-quality water and protecting their legal interests.
