Methodology
How we score water, in plain words.
Every score comes with its band, a factual finding, its basis (measured, modeled or mixed), its confidence and its date.
The five bands
A band describes what was measured or modeled against the strictest health benchmark, never whether water is safe. ELEVATED and HIGH are the AquaGap™ zone: legal, not clean.
| TRACE | All scored contaminants below a small fraction of their health benchmarks. |
|---|---|
| DETECTED | Measurable amounts, still at or below the health benchmarks. |
| ELEVATED | At least one contaminant above its health benchmark. |
| HIGH | At least one contaminant 10 times or more above its health benchmark. |
| SEVERE | At least one contaminant above its enforceable legal limit. |
Published thresholds
The health benchmark for every contaminant, and the cut for TRACE, set by our science panel. [THRESHOLD TABLE: SCIENCE PANEL]
The fixed line on every readout
AquaScore describes what was measured or modeled against health benchmarks. It is not a determination that water is safe or unsafe to drink.
The five actions
Test · Review · Trace · Treat · Report
Changelog
| Oct 12, 2026 | Band codes retired in public. Bands are words only, shown with the score (for example, 72 · ELEVATED). |
|---|---|
| Oct 9, 2026 | Five bands defined by facts in the method, not by score ranges: TRACE, DETECTED, ELEVATED, HIGH, SEVERE. |