New explanatory guides
Groundwater, in perspective.
Read the evidence behind current water-quality questions.
Emerging contaminants
PFAS in Groundwater: What the “Millions at Risk” Headlines Really Mean
Separate national predictions, raw-water detections, and household results before deciding what a PFAS headline means for your supply.
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Private wells
Your Well Looks Clear After a Flood. What Should You Check Before Using It?
A practical evidence trail from safe access and professional assessment to purposeful sampling, results, and follow-up.
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Reading water data
Nitrate or Nitrate-N? The Small Label That Can Change Your Water Report
Learn why two different nitrate numbers can represent the same concentration, and how to compare reports without creating a false trend.
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This restored portal preserves original material. New advance-reading guides are separately attributed and dated. About the new editorial edition.