Per- and Polyfluoroalkyl Substances (PFAS) NPDWR Implementation

On May 18, 2026, EPA announced two proposed rules related to PFAS in drinking water for public comment. These actions deliver on the agency's path forward announced on May 14, 2025. One proposed rule upholds the NPDWR for PFOA and PFOS while strengthening practical implementation by providing an option for drinking water systems to request two additional years - to 2031 - to comply with enforceable limits. Another proposed rule would correct the Biden Administration's failure to follow the clear Safe Drinking Water Act (SDWA) statutory requirements and rescind drinking water regulations for PFHxS, PFNA, HFPO-DA (commonly known as GenX), and the Hazard Index mixture of these three PFAS plus PFBS.

The information and materials contained on this website provide information specific to the 2024 PFAS NPDWR rulemaking and are provided for reference. 

On This Page

• Implementation Products
• Memorandums
• PFAS Sampling, Analysis, and Methods
• PFAS Primacy
• Further Information

Implementation Products

Products to aid with implementation of the PFAS NPDWR are provided below. 

• Control of PFAS Overview: A Quick Reference Guide February2025 (pdf) (1.65 MB)
  • Updated to include EPA method 537.1, version 1.0 as an approved analytical method during the initial monitoring period only.
• PFAS Initial Monitoring: A Quick Reference Guide February2025 (pdf) (1.51 MB)
  • Updated to include EPA method 537.1, version 1.0 as an approved analytical method during the initial monitoring period only.
• PFAS Hazard Index: A Quick Reference Guide (pdf) (1.53 MB)
• PFAS Significant Figures and Rounding Requirements (pdf) (1.61 MB)
• PFAS Compliance Monitoring: A Quick Reference Guide (pdf) (1.46 MB)
• PFAS Compliance Determination: A Quick Reference Guide (pdf) (1.48 MB)
• PFAS Notifications to Consumers: A Quick Reference Guide November2025 (pdf) (649.14 KB)
  • Revised with minor edits to improve clarity regarding Consumer Confidence Report updates.

Memorandums

Memorandums: PFAS National Primary Drinking Water Regulation Monitoring and Reporting

EPA issued two memorandums that provide drinking water primacy agencies, laboratories, and water systems with clarifying information related to the monitoring and reporting requirements under the PFAS NPDWR. The two memorandums are similar and include information on the initial monitoring requirements and how previously collected data, such as data from the fifth Unregulated Contaminant Monitoring Rule (UCMR 5), can be used to satisfy some or all of these requirements and inform PFAS compliance monitoring frequency determinations. Additionally, the memorandums provide information related to laboratory analytical requirements and recommendations for reporting of PFAS drinking water sample results.

• Memorandum for Primacy Agencies: PFAS National Primary Drinking Water Regulation Monitoring and Reporting (pdf) (342.88 KB)
• Memorandum for Laboratory Community and Water Systems: PFAS National Primary Drinking Water Regulation Monitoring and Reporting (pdf) (343.01 KB)

PFAS Sampling, Analysis, and Methods

• Requirements and Best Practices for the Collection and Analysis of Samples for the PFAS NPDWR (pdf) (2.82 MB)
• EPA published a final rule, on January 16, 2025, to allow the use of EPA method 537.1, version 1.0 in satisfying the initial monitoring requirements. For more information, see 90 FR 4658, and this fact sheet.

PFAS Primacy

Memorandum: Primacy Requirements for Control of Per- and Polyfluoroalkyl Substances National Primary Drinking Water Regulation

This memorandum provides general guidance to primacy agencies under the Safe Drinking Water Act (SDWA) concerning the requirements for the NPDWR. This memorandum highlights key implementation deadlines and the requirements for primacy.

• Memorandum: Primacy Requirements for Control of Per- and Polyfluoroalkyl Substances National Primary Drinking Water Regulation (pdf) (320.36 KB)

PFAS Rule Extension Templates

Given EPA’s announcement on May 14, 2025, that it intends to update the PFAS NPDWR, EPA encourages states, territories, and Tribes seeking primacy for implementing the PFAS NPDWR to request additional time from EPA to develop their applications. EPA has developed primacy documents to support extension requests from primacy agencies. 

• Memorandum: Primacy Extension Request Documents for the 2024 Control of Per- and Polyfluoroalkyl Substances National Primary Drinking Water Regulation (pdf) (324.88 KB)
• PFAS NPDWR - Primacy Support Documents (docx) (141.51 KB, September 2025, EPA 815-B-25-006)  featuring:
  1. PFAS Primacy Revision Extension Request Checklist, 
  2. Example Extension Agreement Letter, and 
  3. PFAS Rule Primacy Agency and EPA Implementation Activities Checklist.

PFAS Rule Crosswalk

The rule crosswalk is a side-by-side comparison of the federal requirements and the corresponding State authorities for the development of the primacy application.

• PFAS Rule Crosswalk February2025 (pdf) (531.9 KB)
  • Updated to include approved EPA method 537.1, version 1.0 for initial monitoring requirements (see 90 FR 4658).

Primacy Package Training

EPA held an informational training webinar on November 18, 2024 to provide guidance to primacy agency and EPA regional staff to support the submission of primacy packages. 

• Primacy Package Training Presentation (pdf) (1.09 MB)
• Webinar Recording: Primacy Package Training 

Further Information

Information on the final PFAS NPDWR and supporting materials provided at the time of rollout of the final rule can be found here.