John Spoelstra

• Fate and transport of nitrate and other contaminants in groundwater and surface water.
• Impact of land use on groundwater and surface water quality.
• Use of tracers, such as artificial sweeteners and stable isotopes, to study human impacts on watersheds
• Water quality issues in urbanized watersheds

• Sources and fate of nitrogen-based contaminants in groundwater and surface water
• Development and application of stable isotope tools for biogeochemistry research and contaminant source identification
• Artificial sweeteners as tracers of wastewater in the environment
• Impacts of land management on groundwater and surface water quality in agricultural watersheds
• Water quality issues in urbanized watersheds
• Nutrient cycling and fate in forested catchments and wetlands
• Groundwater quality issues of the Great Lakes Basin
• Impacts of climate change on groundwater in the Yukon

Recent publications include

• Van Stempvoort, D.R., J. Spoelstra, S.J. Brown, W.D. Robertson, R. Post, S.A. Smyth. (2019) Sulfamate in environmental waters. Science of the Total Environment 695: 133734. doi:10.1016/j.scitotenv.2019.133734.
• Hwang, H.-T., S.K. Frey, Y.-J. Park, K.D.M. Pintar, D.R. Lapen, J.L. Thomas, J. Spoelstra, S.L. Schiff, S.J. Brown, E.A. Sudicky. (2019) Estimating cumulative wastewater treatment plant discharge influences on acesulfame and Escherichia coli in a highly impacted watershed with a fully integrated modelling approach. Water Research 157: 647-662. doi:10.1016/j.watres.2019.03.041.
• Baer, S., W.D. Robertson, J. Spoelstra, S.L. Schiff. (2019) Phosphorus and nitrogen loading to Lake Huron from septic systems at Grand Bend, ON. Journal of Great Lakes Research 45: 642-650. doi:10.1016/j.jglr.2019.03.003.
• Spoelstra, J., N.D. Senger, S.L. Schiff. (2017) Artificial sweeteners reveal septic system effluent in rural groundwater.  Journal of Environmental Quality 46: 1434-1443. doi: 10.2134/jeq2017.06.0233.
• Roy, J.W., J. Spoelstra, W.D. Robertson, W. Klemt, S.L. Schiff. (2017) Contribution of phosphorus to Georgian Bay from groundwater of a coastal beach town with decommissioned septic systems. Journal of Great Lakes Research 43(6): 1016-1029. doi: 10.1016/j.jglr.2017.09.001.
• Robertson, W.D., D.R. Van Stempvoort, J.W. Roy, S.J. Brown, J. Spoelstra, S.L. Schiff, D.R. Rudolph, S. Danielescu, and G. Graham. (2016) Use of an artificial sweetener to identify sources of groundwater nitrate contamination. Groundwater 54: 579-587. doi:10.1111/gwat.12399.
• Van Stempvoort, D.R., J. Spoelstra, N.D. Senger, S.J. Brown, R. Post, J. Struger. (2016) Glyphosate residues in rural groundwater, Nottawasaga River Watershed, Ontario, Canada. Pest Management Science 72: 1862-1872. doi:10.1002/ps.4218.Snider, D.M., J.J. Venkiteswaran, S.L. Schiff, and J. Spoelstra. (2015) From the ground up: nitrous oxide sources are constrained by stable isotope values. PLoS ONE 10(3): e0118954. doi:10.1371/journal.pone.0118954.
• Li, L., J. Spoelstra, W.D. Robertson, S.L. Schiff, and R.J. Elgood. (2014) Nitrous oxide as an indicator of nitrogen transformation in a septic system plume. Journal of Hydrology 519: 1882–1894.
• Spoelstra, J., S.L. Schiff, and S.J. Brown. (2013) Artificial sweeteners in a large Canadian river reflect human consumption in the watershed. PLoS ONE 8(12): e82706. doi:10.1371/journal.pone.0082706. 

• Adjunct Assistant Professor, Department of Earth and Environmental Sciences, University of Waterloo (2007 to present)

• Associate Faculty, Faculty of Graduate Studies, Wilfrid Laurier University (2008 to 2015)

The following news stories have featured Dr. Spoelstra's research:

• June 9, 2015 Global News - “Artificial sweeteners that come from a natural source”
• April 2014 Ontario Out of Doors - “Sweet water fishery” 

• December 2013 University of Waterloo scientists find artificial sweeteners in Grand River. Coverage of this story also appeared in the following outlets:

  • Gizmodo - “How Diet Soda Can Be Used to Track Sewage” (18-Dec-2013)
  • www.dailymail.co.uk - “Canadian river artificially sweetened: Researchers find elevated levels of sugar substitute compounds in waterways and drinking water” (17-Dec-2013)
  • Yahoo! News Canada - “Ontario’s Grand River tests highest in the world for artificial sweeteners” (17-Dec-2013)
  • CBC Radio Toronto, Ontario Morning with Wei Chen - “Artificial Sweetener Floods Grand River” (17-Dec-2013)
  • CBC Radio Kitchener (16-Dec-2013) - Artificial sweeteners in the Grand River
  • CKNW Radio British Columbia, Simi Sara Show - “Are our lakes and rivers artificially sweetened?” (16-Dec-2013)
  • The Toronto Star - “Grand River has highest levels of artificial sweeteners on record” (16-Dec-2013)
  • LA Times - “Artificial sweeteners found in river water and drinking supplies” (16-Dec-2013)
  • The Huffington Post Canada - “Artificial sweeteners in Ontario's Grand River 'highest' in the world, study says” (15-Dec-2013)
  • Waterloo Region Record - “Grand River has highest levels of artificial sweetener pollution on record” (13-Dec-2013)
  • CTV News Kitchener - “Sweeteners in the river” (12-Dec-2013)
  • Globe and Mail - “Ontario’s Grand River loaded with artificial sweeteners, study finds” (11-Dec-2013)

2004 PhD Earth Sciences, University of Waterloo, Waterloo, ON, Canada

1996 BSc University of Waterloo, Waterloo, ON, Canada