Has the City ever detected 1,4 Dioxane in any Ann Arbor drinking water source?
Yes. During a routine test in 2001, a trace level of 1,4 Dioxane (1-2 ppb/parts per billion) was detected in water from Ann Arbor’s Northwest Supply well, which was used by the city as a water source during the winter months. The Northwest Supply well water was not being used at the time of the positive test and was immediately closed and remains closed. The Northwest Supply well provided less than 5% of Ann Arbor’s total source water.
