Michigan's Gelman Site 1,4-Dioxane Groundwater Contamination: Still Spreading Decades after Detection.

Disposal practices of industrial wastewater by Gelman Sciences led to high concentrations of 1,4-dioxane in groundwater in Michigan, USA. Since discovery of off-site pollution in 1984, the contaminated groundwater prompted closure of over 124 private wells, closure of one municipal well, and prohibition of most groundwater uses in a large section of the city of Ann Arbor. Recent 1,4-dioxane detections in shallow groundwater in Ann Arbor and in township residential wells pose new exposure threats.