Cathryn Ryan


Department of Geoscience

Associate Dean - Research and Graduate Education

Faculty of Science

Contact information


Office: 403.220.3293


Office : BS540

Research and teaching

Research areas

  • Agricultural impacts on groundwater
  • Impacts on groundwater from unconventional gas development and other oil and gas-related activities
  • Measuring and monitoring dissolved gases in groundwater
  • Wastewater impacted water
  • Understanding geyser behaviour

Research interests

Ongoing and recently completed projects related to agricultural impacts on groundwater include two projects funded by the Canadian Water Network (CWN). As part of The Influence of Dynamic Hydrology on Groundwater Source Security CWN project, my research group  focuses on the Abbotsford Aquifer in British Columbia and its vulnerability to various land uses. The Origin, Occurrence and Fate of Nitrate in Sedimentary Bedrock Groundwater in the Maritimes is a recently completed project that investigated nitrate contamination in groundwater in PEI.

Unconventional oil and gas development has experienced rapid growth in recent years, which has not been matched by scientific research on impacts to groundwater. Through various avenues, my research addresses fundamental knowledge gaps regarding stray gas and other impacts from unconventional oil and gas development. See here for a recently published report on Subsurface impacts of hydraulic fracturing: Contamination, seismic sensitivity, and groundwater use and demand management.

Almost all of my students conduct community and field-focused groundwater and surface water research that includes physical, geochemical, isotope, and contaminant hydrology.  The weather isn't always this good(!).


  • Gao, H., M.C. Ryan, Changyou Li, and Biao Sun, 2017.  Understanding the Role of Groundwater in a Remote Transboundary Lake (Hulun Lake, China). Water. 9 (5), 363.
  • Loo, S. E., M.C. Ryan, B.J. Zebarth, S.H. Kuchta, D. Neilsen, and B. Mayer, 2017. Use of d15N and d18O values for nitrate source identification under irrigated crops: a cautionary vadose zone tale. J. Env. Quality. 46.3: 528-536.
  • Cahill, A,C. Steelman, O. Forde, O. Kuloyo, E. Ruff, B. Mayer, K.U. Mayer, M. Strous, M.C. Ryan, J.A. Cherry, and B.L. Parker, 2017. Mobility and persistence of methane in groundwater in a controlled-release field experiment. Nature Geoscience. 10 (4), 289-294
  • N.Taube, J. He, C. Valeo, and M.C. Ryan, 2016.  Relative importance of P and N in macrophyte and epilithic algae biomass in a wastewater-impacted oligotrophic river. Environmental Monitoring and Assessment. 188:494 DOI: 10.1007/s10661-016-5493-y
  • Ryan, M.C. and Bethune, D.N.(2016). Hydrogeologists Without Borders and the GW2.0 project. Invited contribution to: Water Resources IMPACT. 18: 29-30.
  • Ladd, B and Ryan, M.C.(2016). Can CO2 trigger a thermal geyser eruption?. Geology. 44(4): 307-310.
  • Ryan, M.C., J.W. Roy, and D. Heagle. (2015). Dissolved gas 'concentrations' or 'concentration estimates' - A comment on “Origin, distribution and hydrogeochemical controls on methane occurrences in shallow aquifers, southwestern Ontario.Applied Geochemistry. 63: 218-221.
  • Zebarth (a), B.J., M.C. Ryan, G. Graham, T.A.Forge, and D. Neilsen,. (2015). Groundwater monitoring to support development of BMPs for groundwater protection: The Abbotsford-Sumas aquifer case study. Groundwater Monitoring and Remediation. 35(1): 30-42.
  • Bethune, D.N., A. Chu, and M.C. Ryan. (2015). Passive evaporation of source-separated urine from dry toilets (2 of 3): Prototype design and field testing using municipal water.Journal of Water Sanitation and Hygiene for Development. 5: 392-401.
  • Zebarth (b), B.J., S. Danielescu, J. Nyrianeza, M.C. Ryan, Y. Jiang, M. Grimmett, and D.L. Burton. (2015). Controls on nitrate loading and implications for BMPs under intensive potato production systems in Prince Edward Island, Canada. Groundwater Monitoring and Remediation. 35(1): 82-96.
  • Alley, W.W., J.A. Cherry, B.L. Parker, and M.C. Ryan. (2014). Nuclear waste disposal: A cautionary tale for shale gas development. EOS Transactions. 95: 264.
  • Zhu, D., M.C. Ryan, B. Sun, and C. Li,. (2014). The influence of irrigation and Wuliangsuhai Lake on groundwater quality in eastern Hetao Basin, Inner Mongolia, China. Hydrogeology Journal. 22(5): 1101-1114.
  • Bethune, D.N., A. Chu, and M.C. Ryan. (2014). Passive evaporation of source-separated urine from dry toilets (1 of 3): A lab study.J. Water Sanitation and Hygiene for Development. 4: 654–662.
  • Kuipers P., Ryan M.C., Zebarth B.(2013). Estimating nitrate loading from an intensively managed agricultural field to a shallow unconfined aquifer. Canadian Water Quality Research Journal. 41(1): 10-22.
  • Roy JW, Ryan MC. (2013). Effects of unconventional gas development on groundwater: A call for total dissolved gas pressure field measurements. Groundwater. 51: 480-482.
  • Jackson, R.E., A.W. Gorody, B. Mayer, J.W. Roy, M.C. Ryan and D.R. Van Stempvoort. (2013). Groundwater Protection and Unconventional Gas Extraction: The Critical Need for Field-Based Hydrogeological Research. Groundwater. 51: 488-510.
  • Cantafio, L.J., Ryan M.C.(2013). Mass flux estimation of groundwater discharge from a river-connected, urban alluvial aquifer. Hydrogeology Journal. 22: 957–970.
  • Turnbull, B. and M.C. Ryan, 2013. Decadal and seasonal water quality trends downstream of urban and rural areas in southern Alberta rivers. In press Canadian Water Quality Research Journal (In press). 
  • Motz, E., E. Cey, M.C. Ryan, and A. Chu, 2012. Nutrient fate and transport in the vadose zone below an at-grade wastewater distribution system in a cold climate.  In press, J. Env. Eng. (ASCE) (In press). 
  • Motz, E., E. Cey, M.C. Ryan, and A. Chu, 2012. Vadose zone microbial transport below at-grade distribution of wastewater effluent. Water, Air, and Soil Pollution. 223:771-785.
  • He, J., A. Chu, M.C. Ryan, C. Valeo, and B. Zaitlin, 2011. Abiotic influences on dissolved oxygen in a riverine environment. 37:1804-1814. J. Ecol. Eng. (ASCE).
  • Moore, T.A., Y. Xing, B. Laxenby, S. Schiff, W. Robertson, R. Timlin, S. Lanza, M.C. Ryan, R. Aravena, D. Fortin, I. Clark, and J.D. Neufeld, 2011. Predominance of anaerobic ammonium-oxidizing bacteria in contaminated groundwater. Env. Sci. Tech.  45:7217-7225.
  • Mulligan, B., M.C. Ryan, and T. Padilla Cambera, 2011. Delineating volcanic aquifer recharge areas using geochemical and isotopic tools. Hydrogeology Journal. 19:1335-1347. 
  • Roy, J.A. and M.C. Ryan, 2010. In-well Degassing Issues for Measurements of Dissolved Gases in Groundwater.  Ground Water. 48:869-877.
  • Bethune, D.N. and M.C. Ryan, 2010. The CARA Network: Building Latin American capacity in hydrogeology and water resource management.  Invited contribution. Invited contribution to J. Contem. Water Research and Education. 145:45-50.
  • Robinson, K.L, C. Valeo, M.C. Ryan, A. Chu, and M. Iwanyshyn, 2009.  Periphyton contributions to DO fluctuations in a large river. Can. J. Civ. Eng. 38:492-503.
  • Iwanyshyn, M., M.C. Ryan, and A. Chu, 2009.  A cost-effective approach for continuous major ion and nutrient concentration estimation in a river. J. Env. Eng. (ASCE). 135:218-224.
  • Caron, M.-E., S.E. Grasby, and M.C. Ryan, 2008.  Spring water trace element geochemistry: A tool for resource assessment and reconnaissance mineral exploration.  Appl. Geochem. 23:3561-3578.
  • McCallum, J.E., M.C. Ryan, B. Mayer, and S.J. Rodvang, 2008.  Mixing-induced denitrification beneath a manured field.  Appl. Geochem.  23:2146-2155.
  • Iwanyshyn, M., M.C. Ryan, and A. Chu, 2008.  Separation of physical loading from photosynthesis/respiration processes in rivers by mass balance.  Sci. Total Env.  390:205-214.
  • Sebol, L.A., W.D. Robertson, E. Busenberg, L.N. Plummer, M.C. Ryan, and S.L. Schiff, 2007.  Evidence of CFC degradation in groundwater under pyrite oxidizing conditions. J. Hydrol. 347:1-12.
  • Valeo, C., Z. Xiang, F. J-C. Bouchart, P. Yeung, and M.C. Ryan, 2007.  Climate change impacts in the Elbow River Watershed.  Can. Water Res. J. 32(4):1-18.
  • McLeish, K.L., M.C. Ryan, and A. Chu, 2007.   Integrated sampling and analytical approach for common groundwater dissolved gases.  Env. Sci. Technol. 41:8388-8393.
  • Manwell, B.R. and M.C. Ryan, 2006.  Chloride as an indicator of non-point source contaminant migration in a shallow alluvial aquifer. Water Qual. Res. J. Canada. 41(4):293-397.
  • Vandenberg, J.A., M.C. Ryan, and A. Chu, 2005.  Field evaluation of mixing length and attenuation of nutrients and fecal coliform in a wastewater effluent plume.  Env. Monit. Assess. 107:45-57.


  • 2011 Community Outreach Award, Faculty of Science, University of Calgary
  • 2008 Award for ‘Inspired Community Service’ from The University of Calgary Faculty Association
  • 2007 City of Calgary Award for Individual Environmental Achievement (Awarded September, 2008).
  • 2002 Nomination for President’s Internationalization Achievement Award, University of Calgary.