Terms of use

Effective 2026-07-22.

Use of the data

Hard Water Map presents measured hardness aggregated from public USGS, EPA, and US Census records. Public data has gaps and occasional errors, so the figures are provided as-is, without warranty of accuracy or fitness for a particular purpose. They describe areas, not individual addresses or taps, and are not a substitute for your water utility's official reports or for professional testing and advice. Nothing here is a health or safety determination.

Licensing

The downloadable national county dataset and the embeddable map card are offered under CC BY 4.0 — reuse them with attribution and a link back to hardwatermap.com. The site's design, wording, and software are our own and are not licensed for reuse.

Governing law

These terms are governed by the laws of the Republic of Slovenia and the European Union, and any dispute falls to the competent courts of Maribor, Slovenia.

Operator

Hard Water Map is operated by Moving Data Systems d.o.o., Maribor, Slovenia. Contact: corrections@hardwatermap.com.