Editorial policy

1. Real data only. Every number on a utility page is computed from the EPA files named in the footer. If a value is missing it is shown as missing.
2. Method is public. The method and the computed tables are published so anyone can check a figure.
3. Screening is not compliance. We label UCMR 5 results as screening data and never say a utility "violated" a limit unless SDWIS records a violation.
4. Regulatory status is stated plainly, including that parts of EPA's 2024 PFAS rule are proposed for rescission.
5. Filter claims need a source. A recommendation names the standard and links an NSF, ANSI, EPA or state source. Where we found no source, we say nothing.
6. Commercial links never change the answer. Affiliate links, if ever enabled, appear after the answer, are marked sponsored, and show no prices. No lead selling.
7. Updates. Data are refreshed when EPA publishes new files; each page shows the data date. Corrections are logged on this page.

Correction log

None yet. Corrections are dated here. Report one to [email protected].