Dr. Beth Parker was recently featured in Ground Water Canada Magazine after being interviewed on her vision for the on-campus Bedrock Aquifer Field Facility (BAFF). Funding was approved earlier this year, and the new, research-focused, educational facility will highlight groundwater and serve as a hub for the public and professionals alike.
Read the full Q-and-A with Dr. Parker on G³⁶⁰ and the BAFF here: https://www.groundwatercanada.com/q-and-a-with-beth-parker/
The College of Engineering and Physical Sciences (CEPS) at the University of Guelph recently featured G³⁶⁰ groundwater remediation research headed by Dr. Beth Parker, including team members Dr. Kari Dunfield and Dr. Philip Wanner. The article highlights how new multi-disciplinary methods provide seasonal data that can help protect groundwater using monitored natural attenuation (MNA). With MNA, a range of physical, chemical and biological processes can be used to naturally reduce (attenuate) contaminants, as demonstrated at a historic manufacturing facility in southwestern Ontario.
Read the full article on the CEPS website here and check out the CEPS Twitter feed to add to discussion on this topic.
See the 2019 journal article that inspired this highlight:
Wanner P, Aravena R, Fernandes J, BenIsrael M, Haack EA, Tsao DT, Dunfield KE, Parker BL. Assessing toluene biodegradation under temporally varying redox conditions in a fractured bedrock aquifer using stable isotope methods. Water Res. 2019 Nov 15. doi: 10.1016/j.watres.2019.114986.
We are pleased to announce the publication of a new article in Groundwater Monitoring and Remediation from the G360 Institute Team.
On methods for in-well nitrate monitoring using optical sensors.
MacDonald*, G., Levison, J., Parker, B.L.
The authors would like to acknowledge the Canadian Foundation for Innovation (CFI), Ontario Research Fund: Small Infrastructure, Ontario Research Fund Research Excellence Round 3 Award ORF-RE 03-061 (ORF RE-3), The Canadian Natural Sciences and Engineering Research Council (NSERC) and the University of Guelph School of Engineering for financial support of this research. Norfolk County, the Region of Waterloo and City of Guelph are acknowledged for providing access to wells/field sites. Bill Banks of Banks Groundwater Engineering Ltd. provided valuable technical input throughout the research and is gratefully acknowledged.
University of Guelph School of Engineering
Canadian Natural Sciences and Engineering Research Council
Small Infrastructure, Ontario Research Fund Research Excellence Round 3. Grant Number: ORF-RE 03-061
Canadian Foundation for Innovation (CFI)
Optical sensors are promising for collecting high resolution in-well groundwater nitrate monitoring data. Traditional well purging methods are labor intensive, can disturb ambient conditions and yield an unknown blend of groundwater in the samples collected, and obtain samples at a limited temporal resolution (i.e., monthly or seasonally). This study evaluated the Submersible Ultraviolet Nitrate Analyzer (SUNA) for in-well nitrate monitoring through new applications in shallow overburden and fractured bedrock environments. Results indicated that SUNA nitrate-N concentration measurements during flow cell testing were strongly correlated (R 2 = 0.99) to purged sample concentrations. Vertical profiling of the water column identified distinct zones having different nitrate-N concentrations in conventional long-screened overburden wells and open bedrock boreholes. Real-time remote monitoring revealed dynamic responses in nitrate-N concentrations following recharge events. The monitoring platform significantly reduced labor requirements for the large amount of data produced. Practitioners should consider using optical sensors for real-time monitoring if nitrate concentrations are expected to change rapidly, or if a site’s physical constraints make traditional sampling programs challenging. This study demonstrates the feasibility of applying the SUNA in shallow overburden and fractured bedrock environments to obtain reliable data, identifies operational challenges encountered, and discusses the range of insights available to groundwater professionals so they will seek to gather high resolution in-well monitoring data wherever possible.
We are pleased to announce the publication of a new article in Science of the Total Environment, 622-623: 1178-1192, from the G360 Institute Team.
High resolution spatial and temporal evolution of dissolved gases in groundwater during a controlled natural gas release experiment.
Cahill*, A.G., Parker, B.L., Mayer, B., Mayer, K.U., Cherry, J.A.
Funding for this study was provided by the Natural Sciences and Engineering Research Council of Canada (NSERC) under grant STPGP 463045 – 14 awarded to Professors John Cherry and Beth Parker. Special thanks for field and laboratory assistance are given to Michael Nightingale, Andreas Haggman, Bethany Ladd, Dylan Klazinga, Terri Cheung, Leon Halwa and Alyssa Verdin.
Fugitive gas comprised primarily of methane (CH4) with traces of ethane and propane (collectively termed C1–3) may negatively impact shallow groundwater when unintentionally released from oil and natural gas wells. Currently, knowledge of fugitive gas migration, subsurface source identification and oxidation potential in groundwater is limited. To advance understanding, a controlled release experiment was performed at the Borden Research Aquifer, Canada, whereby 51 m3 of natural gas was injected into an unconfined sand aquifer over 72 days with dissolved gases monitored over 323 days. During active gas injection, a dispersed plume of dissolved C1–3 evolved in a depth discrete and spatially complex manner. Evolution of the dissolved gas plume was driven by free-phase gas migration controlled by small-scale sediment layering and anisotropy. Upon cessation of gas injection, C1–3 concentrations increased to the greatest levels observed, particularly at 2 and 6 m depths, reaching up to 31.5, 1.5 and 0.1 mg/L respectively before stabilizing and persisting. At no time did groundwater become fully saturated with natural gas at the scale of sampling undertaken. Throughout the experiment the isotopic composition of injected methane (δ13C of − 42.2‰) and the wetness parameter (i.e. the ratio of C1 to C2 +) constituted excellent tracers for the presence of fugitive gas at concentrations > 2 mg/L. At discrete times C1–3 concentrations varied by up to 4 orders of magnitude over 8 m of aquifer thickness (e.g. from < 0.01 to 30 mg/L for CH4), while some groundwater samples lacked evidence of fugitive gas, despite being within 10 m of the injection zone. Meanwhile, carbon isotope ratios of dissolved CH4 showed no evidence of oxidation. Our results show that while impacts to aquifers from a fugitive gas event are readily detectable at discrete depths, they are spatially and temporally variable and dissolved methane has propensity to persist.
We are pleased to announce the publication of a new article in Groundwater for Sustainable Development from the G360 Institute Team.
Integrative management of saltwater intrusion in poorly-constrained semi-arid coastal aquifer at Ras El-Hekma, Northwestern coast, Egypt.
Eissa*, M.A., De-Dreuzy, J.R., Parker, B.L.
This study was supported by the Campus France of the French Institute in Cairo, Egypt. The Authors gratefully acknowledge the Science & Technology Development Fund (STDF) in Egypt for funding the project # 6723. Authors would like to thanks the Editors of the journal as well as the reviewers who have generously given up valuable time to review the manuscript.
Saltwater intrusion is a major concern in coastal aquifers, particularly in arid and semiarid regions, where recharge is limited and groundwater withdrawal is the main source of potable water. In Ras El Hekma groundwater occurs in the Pleistocene aquifer as a thin lens of freshwater where groundwater quality is very sensitive to pumping stresses. High groundwater withdrawals from the Pleistocene aquifer deteriorate the groundwater quality along the coast due to upwelling of saltwater into the thin lens freshwater. The Pleistocene aquifer is poorly-constrained; the hydrological and geochemical records are sparse. Therefore, a simple analytical approach has been used in order to address local and regional groundwater management issues, for cases of data scarcity using little known and well defined parameters. The model assumes steady state flow as an initial condition in an isotropic and homogeneous medium, with a sharp interface between the freshwater and seawater wedge. The model combines the hydrogeological and geochemical characterization, adapted to the aquifer geometry, in order to provide global salt and freshwater balances to the Ras El Hekma scale site. The model shows progressive extension of the seawater intrusion zone (x-toe) upon increasing the groundwater withdrawals from 250 m3/day to an order of magnitude of this amount. The x-toe distance has been extended from 1700 to 5000 m from the tip of Ras El Hekma to inland. Such model could be applied to estimate the volume of the freshwater and seawater wedge along the coast as well as to predict the groundwater withdrawals under different pumping scenarios. Seawater intrusion, in the Ras El Hekma area, is caused by the unbalance between the pumping withdrawal rates and the natural recharge from precipitation. The model can be applied for similar hydrogeological systems, specifically, coastal aquifers located in semiarid to arid environments where limited aquifer data is available.