About the author: BJP

Tapped Out is written and maintained by BJP, an independent site owner.

BJP is not a water utility, a certified lab, a water treatment professional, a doctor or a government official, and does not claim any professional credential. The site reads public records and published product data and does the arithmetic in the open. It is not medical, legal or professional advice.

How the water data pages are researched

• County and state pages start from the EPA's public drinking water records: violations and lead sampling from SDWIS, and PFAS sampling from the fifth Unregulated Contaminant Monitoring Rule (UCMR 5). Each page shows the date the data was pulled.
• Hardness comes from a utility's own annual water quality report where we could find one, linked on the page. Otherwise we use a lower-confidence estimate, and every hardness figure carries a label saying which kind it is.
• City guides draw on the utility's own reports and public records and list their sources on the page.
• A PFAS detection is reported as a detection, not a violation, and the federal limits and their status are stated with the date they were last checked.

How the calculators are built and checked

• Every formula is written out on the page, with its assumptions labeled, so you can check it by hand.
• Figures such as salt use, softener capacity or well disinfection doses come from government, university extension or manufacturer sources, linked with the date they were checked.
• Automated tests check the math and page structure before every release, and a release check blocks publishing if required notices, sources or links are missing.

Corrections

Public records can be out of date or wrong, and so can we. If a figure looks off or a source has changed, please say so through the contact page. Corrections are made on the page and its date is updated. See how we calculate and the full list of sources, and about Tapped Out for how the site is run.

Last updated November 3, 2026.