<p>In Massachusetts, mains water is delivered by local public water systems, regulated by the Massachusetts Dept of Environmental Protection (MassDEP), Drinking Water Program under the US EPA Safe Drinking Water Act. Typical hardness: Soft to moderately hard; Boston / MWRA supply soft (~15 to 20 ppm). For a specific ZIP, see the EWG Tap Water Database.</p>
Sources: Massachusetts Dept of Environmental Protection (MassDEP), Drinking Water Program, EWG Tap Water Database