US Hard Water & Water Quality Stats 2026

Open dataset of 160 US and global drinking water statistics compiled by Water System Guide: water hardness (USGS classes, domestic wells, utility reports for 11 cities), softener adoption, public water system violations, lead service lines, PFAS (UCMR 5), private wells, chloride and softener regulation, salt use, appliance scaling, consumer concern and global access. Each row quotes one figure as its publisher states it, with source name, title, URL, source date and retrieval date. All 160 were checked against 64 live primary sources on 2026-10-11. CSV and JSON, plus docs and a small Python script. Compilation licensed CC BY 4.0; each figure stays credited to its original publisher. Canonical record: https://doi.org/10.5281/zenodo.23534609