City of Ann ArborCity drinking water comes from the Huron River and groundwater wells that are monitored regularly before and after treatment to ensure the drinking water remains safe from 1,4-dioxane and other contaminants. This dashboard shows the results of this monitoring and includes context and links for why this monitoring is necessary. You can also download the raw sample data from the dashboard.1-4-dioxane-monitoring-dashboardengAnn Arbor Data CatalogPublicEnvironmentInfrastructureDrinking Water and Source Water 1,4-Dioxane Monitoring DashboardDatasetsMichigan--Ann ArborMichiganLast Modified: 2025-09-24