Date: May 14, 2025
EPA said it would retain the 4.0 ppt maximum contaminant levels for PFOA and PFOS while planning to move compliance from 2029 to 2031. It also announced plans to rescind the limits for four other PFAS, which affects which analytes drinking water labs must report.
What it means for calibration
Labs reporting near 4.0 ppt are working at the bottom of their calibration range, where an unweighted fit is most likely to bias results. Low-end accuracy is what decides whether a system is in or out of compliance.
Source: www.epa.gov
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