Start with the provider name on your water bill. ZIP and city boundaries do not necessarily match a water utility’s service area. A Consumer Confidence Report (CCR) describes the utility’s water, while your building’s plumbing can affect your tap.
Verified utility sources
This is a growing, manually checked directory. Each entry links to the utility’s own publication; it is not a complete national list.
Hardness has not been transcribed into this index. Source checked 2026-09-29.
Hardness has not been transcribed into this index. Source checked 2026-09-29.
Hardness has not been transcribed into this index. Source checked 2026-09-29.
Hardness has not been transcribed into this index. Source checked 2026-09-29.
Hardness: 280 ppm average. Source checked 2026-09-29.
Hardness: 172–302 ppm. Source checked 2026-09-29.
Hardness: 18–100 ppm. Source checked 2026-09-29.
If your utility is missing
- Check the utility name on your bill or ask your landlord. For a private well, annual public-utility reports do not describe your water.
- Use the EPA Consumer Confidence Report search, or visit your provider’s official website and look for “water quality report” or “CCR.”
- Ask for “total hardness in mg/L as CaCO₃,” the reporting period, and whether the result is an average or range. A missing hardness entry does not mean soft water.
Once you have a result
Use the hardness converter and capacity calculator, or follow our guide to reading a utility report. For health concerns, find a certified drinking-water laboratory through your state.
Help improve a source
Send a public report link, utility name and reporting year to hello@hardwaterindex.com. Please omit account numbers, addresses and other personal information. We review corrections before publishing them.