Scoring methodology · Bottled water
Every bottled water is evaluated against 7 rules, worth a total of 171 points. Your score is the percentage of points the product earns on what we actually know about it.
Quality score
Each rule contributes points up to a known maximum. We sum them, divide by the total possible, and that's the headline number on the product.
Unknowns
If we couldn't verify an attribute, that rule earns zero. Brands aren't rewarded for non-disclosure, and we don't fill the gap with a guess.
lab_report
A full third-party lab report has been indexed for this product. Acts as the keystone for trusting all other lab-derived claims.
contaminants
No harmful contaminants flagged on this product. When contaminants are present, points are reduced based on severity, amount, and exceedance of regulatory guidelines.
water_source
Where the water comes from. Natural mineral-rich sources score highest; municipal/tap and rainwater score lower; unknown source earns no credit.
heavy_ro_purification
Premium sources (spring, aquifer, iceberg) passed through reverse osmosis lose most of their mineral content. This rule earns full marks unless that combination is present.
packaging
Bottle material. Glass earns full marks. Plastics shed nano/microplastics, with PET and polystyrene the worst offenders. A "certified no plastic" claim recovers half the lost points.
cap_material
Painted-metal caps and crowns can leach into the water. A "certified no plastic" claim overrides this penalty.
pfas_testing
Whether the product has been tested for PFAS (forever chemicals). A small but explicit credit for disclosure.
Scoring is a function applied to evidence. If you think a rule fired on the wrong evidence, the per-product breakdown shows the source for every contribution — each one is challengeable. The methodology itself is version-controlled and evolves in public.
