External verification provides the main mechanism for independent evaluation and review of environmental models implemented by the Agency. It should include an examination of the numerical technique in the computer code for consistency with the conceptual model and governing equations. For more general information on how EPA develops and evaluates models, see the EPA document Guidance on the Development, Evaluation, and Application of Environmental Models. The linked copy includes some yellow highlighting of text used in this website for describing peer and verification reviews.

Independent testing of the code once it is fully developed can be useful as an additional check of integrity and quality. The purpose of external verification is verification that the code has no inherent numerical problems while obtaining a solution. Mechanisms of external verification includes code verification to make sure the code performs according to model design specifications.

The PRG calculator results were verified by external entities by conducting a numerical verification of calculator results.

June 17, 2022 to August 8, 2022

EPA PRG Calculator Review Complete Package, which includes a Verification Study Charge by:

1. Dr. Boby Abu-Eid (Nuclear Regulatory Commission)
• Review
• Curriculum Vitae
• Conflict of Interest Certification
2. Bart Eklund (Haley & Aldrich)
   • Review
   • Curriculum Vitae
   • Conflict of Interest Certification
3. Brooke Stagich (Savannah River National Laboratory)
• Review
• Curriculum Vitae
• Conflict of Interest Certification

February 15, 2017 to April 3, 2017

EPA PRG Calculator Review Complete Package, which includes a Verification Study Charge by:

1. G Timothy Jannik (Savannah River National Laboratory)
• Review
• Curriculum Vitae
• Conflict of Interest Certification
2. Mark Hogue (Savannah River Nuclear Solutions, LLC)
   • Review
   • Curriculum Vitae
   • Conflict of Interest Certification

April 24, 2015 to September 30, 2015

EPA PRG Calculator Review Complete Package, which includes a Verification Study Charge by:

1. G Timothy Jannik (Savannah River National Laboratory)
• Review
  • Calculations for Resident Spreadsheet
  • Calculations for Recreator Spreadsheet
  • Calculations for Farmer Spreadsheet
  • Calculations for Indoor and Outdoor Workers Spreadsheet
  • Calculations for Composite Worker Spreadsheet
  • Calculations for Construction Spreadsheet
  • Calculations for Resident Groundwater Spreadsheet
• Curriculum Vitae
• Conflict of Interest Certification
2. Wm. Thomas Pentecost (Colorado Department of Public Health and Environment (Retired))
   • Review
   • Curriculum Vitae
   • Conflict of Interest Certification