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KnowYourWellWater

Research Methodology

Last reviewed October 25, 2026

Our content is documentary research: we gather, compare and summarize authoritative public information. Here is how.

How a guide is built

  1. 1Define the reader’s question and the search intent behind it.
  2. 2Collect primary sources (EPA, USGS, CDC, state agencies) and extract the relevant facts.
  3. 3Separate health-based limits from aesthetic standards, advisories and classifications.
  4. 4Draft in plain language with explicit "what to check" and "when to call a professional" sections.
  5. 5Review for accuracy against the cited sources, then publish with a review date.

How our tools calculate

Our calculators use published, verifiable relationships — for example, Boyle’s law for pressure-tank drawdown and the Hazen-Williams equation for pipe friction. Formulas are unit-tested, and each tool states its assumptions and the data it still needs. Tools provide estimates for orientation, not specifications.

Reference values

Reference thresholds in our Water Test Interpreter are drawn from EPA primary and secondary drinking water standards and USGS classifications, with each value labeled by its nature (health-based, aesthetic, action level, advisory, or classification).