WaterKnown

Water quality data is public and almost nobody reads it. It sits in utility Consumer Confidence Reports, EPA monitoring files, and brand lab reports written to be skimmed past. WaterKnown pulls it into one place, translates it, and scores it, with the citation under every number so you can check the work.

The scoring is the opinionated part. Results are compared to health-based guidance levels, which are usually far stricter than legal limits, so plenty of legal water does not clear 80 out of 100. Every utility and every brand gets the same yardstick, and a brand that does not publish a current report gets a disclosure flag instead of an invented score. That rule produced the site's most honest finding: the FDA tested 197 bottled waters for PFAS, found detections in ten, and never named which ten, so WaterKnown does not score bottled brands at all.

The heavy lifting was data: every result from the EPA's UCMR 5 PFAS testing across 10,297 water systems (3,539 had a detection), plus utility reports, state testing programs, and NSF certification listings, rolled into city lookups, a state-by-state PFAS map, and plain-English guides like how to read your water quality report. The site states its own limits up front: it does not run lab panels, and it defers to the EPA, ATSDR, and CDC on health effects.

A 180-product filter directory, where each model is checked against the NSF and WQA certification databases before it gets a claim. Buying through a link pays an Amazon commission at the same rate whatever the product scores, and no manufacturer pays anything. It is the right shape for this topic: someone who just learned their city has PFAS is close to buying a filter, and the useful answer is which filters are certified for that exact contaminant. So far 10 of the 180 are fully verified. Finishing that verification is the work that turns traffic into revenue, and nothing has been earned yet.