EPA issues guidance on PFAS NPDWR sampling and analysis best practices

EPA published a guidance/fact sheet on requirements and best practices for collecting and analyzing PFAS samples to support compliance with the PFAS National Primary Drinking Water Regulation (NPDWR). The document highlights method-use boundaries under 40 CFR 141.901 (including that EPA Method 537.1 v1.0 is allowed for initial monitoring only) and provides field/lab QA/QC practices intended to prevent PFAS contamination and ensure defensible monitoring data for compliance determinations.