Different measurements answer different questions
Temperature, dissolved oxygen, bacteria, nutrients, metals, flow, and other measurements describe different parts of a river system. A reading for one parameter does not automatically tell you about every other parameter.
Context changes interpretation
Location, date, rainfall, season, tide, flow, sampling method, and laboratory limits can affect what a value means. The same number can require different context in different reaches or conditions.
Where to find safety guidance
Use official local and state advisories for decisions about swimming, drinking water, fish consumption, flooding, or other immediate risks. Rivistry is an educational monitoring tool that helps explain evidence and trends; it is not a safety determination.