Skip to Main Content U.S. Department of Energy
Environmental Sustainability Division

Catherine MR Yonkofski

Catherine MR Yonkofski

Pacific Northwest National Laboratory
PO Box 999
Richland, WA 99352


Catherine Yonkofski (née Ruprecht) is a research scientist and technical team lead for the Computational Subsurface Hydrology Team within the Hydrology Group at PNNL. Prior to joining PNNL in 2014, she completed her PhD using multiphase, multicomponent numerical modeling to study secondary trapping mechanisms in geologic CO2 storage systems. At PNNL, Dr. Yonkofski works as a computational hydrogeologist specializing in development and application of subsurface simulation tools for use in characterization and interpretation of complex flow systems, predictive fate and transport modeling, and optimization of engineered systems.

Research Interests

  • Numerical Modeling of Multiple-phase Subsurface Flow and Transport
  • Geologic Carbon Sequestration
  • Fate and Transport of Environmental Contaminants
  • Groundwater Resource Assessments
  • Subsurface Energy Resource Engineering

Education and Credentials

  • B.S., Mathematical Sciences, Clemson University
  • M.S., Environmental Engineering and Science, Clemson University
  • Ph.D., Environmental Engineering and Science, Clemson University

Affiliations and Professional Service

  • NGWA Groundwater Modeling Advisory Panel
  • Washington Hydrogeology Symposium

Awards and Recognitions

  • 2015 - PNNL Outstanding Performance Award
  • 2016 - PNNL Outstanding Performance Award
  • 2017 - R&D 100 Award

PNNL Publications


  • Bacon D.H., C. Yonkofski, C.F. Brown, D.I. Demirkanli, and J.M. Whiting. 2019. "Risk-based Post Injection Site Care and Monitoring for Commercial-Scale Carbon Storage: Reevaluation of the FutureGen 2.0 Site using NRAP-Open-IAM and DREAM." International Journal of Greenhouse Gas Control 90. PNNL-SA-140302. doi:10.1016/j.ijggc.2019.102784
  • White M.D., C. Yonkofski, J.A. Horner, and H.T. Schaef. 2019. Final Report for DOE NETL Gas Hydrate Project FWP 65213. PNNL-28462. Richland, WA: Pacific Northwest National Laboratory. Final Report for DOE NETL Gas Hydrate Project FWP 65213
  • Yonkofski C., D. Appriou, and J.L. Downs. 2019. Dust Control Planning. PNNL-29152. Richland, WA: Pacific Northwest National Laboratory. Dust Control Planning



  • Murdoch L., S. Xie, R.W. Falta, and C. Yonkofski. 2015. "Effects of Increased Upward Flux of Saline Water Caused by CO2 Storage or Other Factors." Journal of Hydrology 527. PNNL-SA-106621. doi:10.1016/j.jhydrol.2015.05.022

Earth Systems Science External

ESSD Capabilities

ESSD Technical Groups

Related Links


Technical Groups