The calm, credible, vendor-agnostic auditor of American tap water.
Not the loudest voice. Not the most alarming. The most honest.
Why we exist
American tap water is the most regulated consumer product in the country. The Safe Drinking Water Act imposes monitoring, reporting, and enforcement requirements that make the U.S. supply among the most tested on earth. And yet the two most visible sources of information about it are, on one side, advocacy organizations with an interest in making contamination appear as widespread and alarming as possible, and on the other, filter brands diagnosing you with a problem that their exact product solves.
Neither source has a strong incentive to tell you that your water is fine, or to tell you the difference between a legal limit and a health goal, or to explain why a filter that holds NSF 53 for lead is not the same as one that holds only NSF 42.
WaterQualityLens exists to close that gap. We take the same public EPA records those other sources use and present them accurately, with the reference thresholds labeled correctly and the filter certifications sourced directly from NSF International — not from manufacturer marketing copy.
Principles
Provenance on every number
Every measurement links back to an EPA SDWIS record or a published NSF certification listing. We do not originate data — we surface and contextualize public records. If a number can't be sourced, it doesn't appear.
Independence from hardware sales
We carry no inventory and have no financial interest in which filter you choose. Affiliate links are disclosed per FTC guidelines and never reorder results. The ranking algorithm is public — it sorts by certification match, then dwelling fit, then price.
No fear-based ratings
We use MCL and MCLG as our only reference thresholds — the values produced by EPA's scientific review process. We do not apply third-party advocacy thresholds or produce a single "water quality score" designed to make contaminants appear more alarming than the regulatory science supports.
Data & standards partners
See it in action
Enter any U.S. address to pull live EPA data for the supplying utility, compare against federal limits, and see exactly which certified filters apply.