About WaterListed
An independent directory of official testing-lab lists for people on private wells, and the rules that apply when you test, buy or sell a home with a well or septic system.
Who runs it
ZILIO Marzena Rewers, sole trader registered in the Polish business register (CEIDG)
ul. Gliwicka 35, 42-600 Tarnowskie Góry, Poland
E-mail: [email protected]
NIP 6451705993 (EU VAT PL6451705993)
WaterListed is not a laboratory, a government agency or a water utility, and it is not affiliated with any state agency or the U.S. EPA. Full operator details are in the legal notice.
Where the listings come from
Every drinking-water lab listing is copied from an official certification list: 45 state lists (Wyoming’s via U.S. EPA Region 8), 3,361 listings for 2,291 distinct labs as of 2026-11-15. We keep each raw file with its download date and SHA-256 checksum, link every lab page to it, and re-download the lists every week. When a list changes, the lab page says what changed and when. Asbestos and lead labs come from the NIST NVLAP directory and EPA’s NLLAP list; backflow testers from each water utility’s own approved-tester list; septic and well rules at sale from the county or state rule itself.
Some pages add figures from other official sources: the U.S. Geological Survey (people on private wells, arsenic estimates), EPA (radon zones, PFAS results in public water under UCMR 5) and the Census Bureau (age of housing). Each figure names its source and period; the sources page lists them with refresh cycles.
How we check what we publish
- Certification facts (who is certified, for what, until when) come only from the official list. Nothing is inferred. A field the list leaves blank stays blank, and the page says so.
- What a lab says about itself (homeowner samples, prices, turnaround) is read on the lab’s own website, then re-read by a second, independent check before it is shown. Each item carries the page and the date it was read, and is re-checked within 90 days.
- Articles and guides are drafted from official sources only. Before an article goes live, a second check that did not write it opens every cited source and marks each claim correct, wrong, unsupported or overstated; nothing goes live with a wrong or unsupported health or limit claim. Each article shows the date it was last updated and lists its sources.
- Rules about home sales (septic and well inspections) are taken from the ordinance or regulation, with the citation and the date we read it. A link checker re-tests every official link each month.
What we do not do
- No paid placements and no ratings. A listing is not an endorsement, and the order of labs never depends on payment.
- No affiliate links next to certified listings. Kansas-sourced labs are never used for outreach or sponsored placements (K.S.A. 45-230).
- Business details only: we do not publish lab contacts’ names, mobile numbers, or businesses named after a person.
- General information, not medical, legal or real-estate advice. Confirm tests and rules with the lab or agency.
Corrections and right of reply
If a listing or a figure is wrong, write to us with the page address. Labs and companies can ask for a correction or for their listing to be removed (how we handle listings). Certification data is corrected at the source: we point you to the agency that publishes the list, and our page follows its next version.
This page was last reviewed on 15 Nov 2026.