Private wells need their own evidence
A nearby well or geology signal can make arsenic worth testing, but only a sample from the household well establishes the concentration in that water.
Public-system records need dates and scope
The site keeps the provider, sampling period, unit, and comparison context together instead of reducing everything to a vague safe/unsafe label.
Target the test
If arsenic is the relevant question, start with arsenic rather than paying for a broad package solely because it contains many analytes.