<p>In Indiana, mains water is delivered by local public water systems, regulated by the Indiana Dept of Environmental Management (IDEM), Drinking Water Branch under the US EPA Safe Drinking Water Act. Typical hardness: Hard; groundwater generally 20 to 400 ppm, Indianapolis area ~320 ppm. For a specific ZIP, see the EWG Tap Water Database.</p>
Sources: Indiana Dept of Environmental Management (IDEM), Drinking Water Branch, EWG Tap Water Database