<p>In Delaware, mains water is delivered by local public water systems, regulated by the Delaware Division of Public Health (DHSS), Office of Drinking Water under the US EPA Safe Drinking Water Act. Typical hardness: Moderately hard (statewide roughly 100+ ppm; Wilmington ~127 ppm). For a specific ZIP, see the EWG Tap Water Database.</p>
Sources: Delaware Division of Public Health (DHSS), Office of Drinking Water, EWG Tap Water Database