<p>In Ohio, mains water is delivered by local public water systems, regulated by the Ohio EPA, Division of Drinking and Ground Waters (DDAGW) under the US EPA Safe Drinking Water Act. Typical hardness: Hard to very hard; statewide avg ~155 ppm, varies by city. For a specific ZIP, see the EWG Tap Water Database.</p>
Sources: Ohio EPA, Division of Drinking and Ground Waters (DDAGW), EWG Tap Water Database