Joseph Ryan
Environmental Engineering

Office: SEEC S286B


  • Ph.D., Civil and Environmental Engineering, Massachusetts Institute of Technology, 1992
  • M.S., Civil and Environmental Engineering, Massachusetts Institute of Technology, 1988
  • B.S., Geological Engineering, Princeton University, 1983

Honors and Distinctions:

  • Pacesetter Award; Science, Medicine, and Health, Boulder Daily Camera, 2008
  • U.S. E.P.A. National Notable Achievement Award, Member of the Lefthand Watershed Revitalization Team, 2006

Professional Affiliations:

  • American Geophysical Union
  • American Chemical Society
  • Association of Environmental Engineering and Science Professors


  • Fate and transport of contaminants in natural waters

Latest Publications:

  1. Sherwood O.A., Rogers J.D., Lackey G., Burke T.L., Osborn S.G., and Ryan J.N., 2016.  Groundwater methane in relation to oil and gas development and shallow coal seams in the Denver-Julesburg Basin of Colorado.  Proceedings of the National Academy of Sciences 113(30), 8391-8396.
  2. Thurman E.M., Ferrer I., Rosenblum J., Linden K., and Ryan J.N., 2016.  Identification of polypropylene glycols and polyethylene glycol carboxylates in wastewater from hydraulic fracturing.  Journal of Hazardous Materials 323, Part A, 11-17.
  3. Mohanty S.K., Saiers J.E., and Ryan J.N., 2016. Colloid mobilization in a fractured soil: Effect of pore water exchange between preferential flow paths and soil matrix.  Environmental Science & Technology 50(5), 2310-2317.
  4. Webster J.P., Kane T.J., Obrist D., Ryan J.N., and Aiken G.R., 2016. Estimating mercury emissions resulting from wildfire in the western United States. Science of the Total Environment 568, 578-586.
  5. Poulin B.A., Aiken G.R., Nagy K.L., Manceau A., Krabbenhoft D.P., and Ryan J.N., 2015.  Mercury transformation and release differs with depth and time in a contaminated riparian soil during simulated flooding.  Geochimica et Cosmochimica Acta 176, 118-138.
  6. Rogers J.D., Burke T.L., Osborn S.G., and Ryan J.N., 2015. A framework for identifying organic compounds of concern in hydraulic fracturing fluids based on mobility and persistence in groundwater.  Environmental Science & Technology Letters 2, 158-164.
  7. Writer J.H., Antweiler R.C., Ferrer I., Ryan J.N., and Thurman E.M., 2013.  In-stream attenuation of neuro-active pharmaceuticals and their metabolites. Environmental Science & Technology 47(17), 9781-9790.
  8. Craven A.M., Aiken G.R., and Ryan J.N., 2012. Copper(II) binding by dissolved organic matter: Importance of the copper-to-dissolved organic matter ratio and implications for the biotic ligand model. Environmental Science & Technology 46(18), 9948-9955.
  9. McCleskey R.B., Nordstrom D.K., Ryan J.N., and Ball J.W., 2012. A new method of calculating electrical conductivity with applications to natural waters.  Geochimica et Cosmochimica Acta 77, 369-382.
  10. Gerbig C.A., Kim C.S., Stegemeier J.P., Ryan J.N., and Aiken G.R., 2011. Formation of nanocolloidal metacinnabar in mercury-DOM-sulfide environmental systems.  Environmental Science & Technology 45, 9180-9187.