PFAS · PFAS and the Operator
What Does Parts per Trillion Mean for PFAS Results?
PFAS results in water are commonly reported in nanograms per liter. One nanogram per liter is one part per trillion for water under ordinary dilute conditions. Solids may be reported in nanograms per gram. These units are extremely small, which makes contamination control and data review essential.
A detected number should be read with its reporting limit, qualifier, blank results, and quality-control information. A non-detect does not prove that no PFAS is present. It means the laboratory did not report the analyte at or above the applicable limit under that test.
Do not compare water and solids numbers as though the units were interchangeable. Do not add non-detects as zeros unless the approved data procedure says to do so. Preserve the original laboratory notation.
Key point: At trace concentrations, the sampling and quality record is part of the result.
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PFAS in Wastewater: Sources, Sampling, Source Control, and Residuals
This page comes from the course. It covers PFAS sources in the sewershed, how PFAS moves through a treatment plant, sampling and lab methods, source control, treatment residuals and biosolids, one step at a time, with short knowledge checks and a certificate of completion.
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