There is concern that if your home in Scio Township is near the plume and has a well, that you could be exposed to 1,4-dioxane in your drinking water. For this reason, the Michigan Department of Great Lakes, Environment and Energy (EGLE) contracts with the Washtenaw County Health Department to conduct long-term monitoring of drinking water wells around the plume. Drinking water wells within 1,000 feet of the estimated plume boundary are included in this state-funded monitoring. Approximately 218 drinking water wells are sampled either twice per year, once per year, or every-other year, depending on how close they are to the plume and nearby detections.
If you would like more information about the proximity of your well to the plume, including a review of your well drilling record and information on the depth to contaminated groundwater in your area, or information on where to have your well tested for 1,4-dioxane, please contact Jennifer Conn at (734) 222-3855 or [email protected].
If you live within the Ann Arbor City limits you are connected to the City's municipal water supply. Within the city limits there is an institutional control called the "Prohibition Zone" that restricts groundwater use in order to prevent exposure to contaminated groundwater. Properties within the Prohibition Zone should not be using well water for any reason. This means no irrigation wells or open-loop geothermal heat pump systems.
The City of Ann Arbor's municipal water supply, most of which comes from Barton Pond in the Huron River, is sampled monthly for 1,4-dioxane. 1,4-dioxane has been detected in the City's municipal water supply, but at levels below the laboratory reporting limit. The laboratory reporting limit is the smallest amount of a substance that can be accurately measured by the laboratory tools. 1,4-dioxane has been detected at levels up to 0.059 parts per billion (ppb), below the reporting limit of 0.07 ppb and more than 100 times lower than the drinking water criteria of 7.2 ppb. The City's monthly 1,4-dioxane sampling results can be viewed on their Water Treatment webpage under 'Keeping Our Customers Informed: Dioxane.'