Indianapolis Water Hardness & Quality Report (2026)

Citizens Energy Group provides drinking water to Indianapolis and surrounding areas in Marion County, Indiana, serving over 800,000 people. Primary sources include the White River and reservoirs such as Geist Reservoir, Morse Reservoir, and Eagle Creek Reservoir. Water is treated at four main facilities: Fall Creek, Riverside, South Treatment Plant, and West Treatment Plant, which handle surface and groundwater blending. Treatment processes include coagulation, sedimentation, filtration, chloramination, and fluoridation for dental health, with results published in regular Consumer Confidence Reports.

The White River watershed drains central Indiana through the limestone-dominated terrain of the Central Till Plain. Key geological features include Devonian and Mississippian limestone and dolomite formations—notably the Jeffersonville Limestone and Geneva Dolomite—which form karst aquifers. As water percolates through these carbonate rocks and fractures, it dissolves calcium and magnesium ions, imparting a naturally hard character to the supply before treatment.

Hard water in Indianapolis causes significant scale buildup in pipes, water heaters, dishwashers, washing machines, and coffee makers, with visible mineral deposits and energy cost increases of up to 20–30%. Regular descaling, vinegar rinses, and professional maintenance are advised; a water softener is highly recommended to prevent spotting on dishes, dry skin, and reduced soap efficiency. Water typically has pH 7.5–8.5 and complies with EPA Lead and Copper Rule requirements. No notable PFAS exceedances are reported in recent Consumer Confidence Reports; minor detections of TTHMs and other disinfection byproducts remain below legal limits.