1,4-Dioxane contamination of German drinking water obtained by managed aquifer recharge systems: Distribution and main influencing factors.

1,4-Dioxane, a cyclic ether that has been classified as a class 2B carcinogen by the US-EPA, is a substance of growing environmental concern because of its abundant occurrence in surface waters worldwide. Its high polarity and low biodegradability hamper its retardation in aquifer systems. Previous investigations in Germany have shown that 1,4-dioxane is already widely distributed in rivers and can be found in groundwater at contamination sites.