Field evidence of hydraulic connections between bedrock aquifers and overlying granular aquifers: examples from the Grenville Province of the Canadian Shield

Richard, Sandra K.; Chesnaux, Romain; Rouleau, Alain; Morin, Roger H.; Walter, Julien; Rafini, Silvain

doi:10.1007/s10040-014-1183-4

Cited by 21 publications

(15 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These samples could correspond to mixed or intermediate water types from granular and bedrock aquifers (Frape et al, 1984;Rajmohan and Elango, 2004;Subramani et al, 2010). This last observation highlights the possibility of hydraulic connections between the Canadian Shield bedrock and the granular deposits as recently demonstrated by Chesnaux et al (2012) and Richard et al (2014). The Cluster 4 samples would therefore correspond to more saline and probably more mature water from bedrock aquifers (Frape et al, 1984;Gascoyne and Kamineni, 1994).…”

Section: Interpretation and Discussionmentioning

confidence: 69%

“…The Cluster 2 and Cluster 3 intermediate or mixed groundwater samples are less strongly influenced by the two first factors than the other cluster samples. The Cluster 2 and Cluster 3 (Ca-Na)-HCO 3 groundwaters could correspond to mixed or intermediate groundwater between Cluster 1 and Cluster 4 from possibly interconnected granular and bedrock aquifers (Chesnaux et al, 2012;Richard et al, 2014). The Cluster 3 samples are more influenced by Factor 3 (Si 4+ ).…”

Section: Interpretation and Discussionmentioning

confidence: 97%

See 1 more Smart Citation

Scenarios of groundwater chemical evolution in a region of the Canadian Shield based on multivariate statistical analysis

Ghesquière

Walter

Chesnaux

et al. 2015

Journal of Hydrology: Regional Studies

Self Cite

View full text Add to dashboard Cite

a b s t r a c tStudy region: The study of groundwater chemistry of the Charlevoix/HauteCôte-Nord (CHCN) region in the province of Quebec in Canada is part of a regional hydrogeological characterization project. Study focus: Groundwater was sampled in 113 wells over the 4500 km 2 study area and analyzed for 39 parameters including major, minor, trace and inorganic constituents, plus stable isotopes 2H and 18O. Two multivariate statistical methods, hierarchical cluster analysis (HCA) and R-mode factor analysis (RFA) were combined with graphic methods to classify the samples according to plausible levels of groundwater evolution in that region. New hydrological insights for the region: Four sample clusters were identified. Cluster 1 is composed of low-salinity Ca-HCO 3 groundwater corresponding to recently infiltrated water in surface granular aquifers in recharge areas. Cluster 4 Na-(HCO 3 -Cl) groundwater is more saline and corresponds to more evolved groundwater probably from confined bedrock aquifers. Cluster 2 and Cluster 3 (Ca-Na)-HCO 3 and Ca-HCO 3 groundwater, respectively, correspond to mixed or intermediate water between Cluster 1 and Cluster 4 from possibly interconnected granular and bedrock aquifers. This study identifies groundwater recharge, water-rock interactions, ion exchange, solute diffusion from marine clay aquitards, saltwater intrusion and also hydraulic connections between the Canadian Shield and the granular deposits, as the main processes affecting the hydrogeochemical evolution of groundwater in the CHCN region.

show abstract

Section: Interpretation and Discussionmentioning

confidence: 69%

Section: Interpretation and Discussionmentioning

confidence: 97%

Scenarios of groundwater chemical evolution in a region of the Canadian Shield based on multivariate statistical analysis

Ghesquière

Walter

Chesnaux

et al. 2015

Journal of Hydrology: Regional Studies

Self Cite

View full text Add to dashboard Cite

show abstract

“…More precisely it is verified if (1) the distinctive shape of the curve plotted in the velocity graph is associated with leaky flow, and (2) the different flow pathways suggested by Chapuis et al () actually represent the different stages of the falling‐head permeability test that are observed. The numerical model is based on actual field data, where leaky flow along the casing has been previously observed and confirmed by well‐logging investigations (Richard et al ).…”

Section: Introductionmentioning

confidence: 80%

“…Geophysical logs of cumulative flow during pumping (0.21 L/s) and fracture orientation obtained in well PZ‐104‐R. S = sandy unit; C = clay unit; T = till unit; Sh = shale unit; Ca = calcareous unit; R = Precambrian (crystalline) rock (after Richard et al ).…”

Section: Field Datamentioning

confidence: 99%

Detecting a Defective Casing Seal at the Top of a Bedrock Aquifer

2015

Self Cite

View full text Add to dashboard Cite

An improperly sealed casing can produce a direct hydraulic connection between two or more originally isolated aquifers with important consequences regarding groundwater quantity and quality. A recent study by Richard et al. (2014) investigated a monitoring well installed in a fractured rock aquifer with a defective casing seal at the soil-bedrock interface. A hydraulic short circuit was detected that produced some leakage between the rock and the overlying deposits. A falling-head permeability test performed in this well showed that the usual method of data interpretation is not valid in this particular case due to the presence of a piezometric error. This error is the direct result of the preferential flow originating from the hydraulic short circuit and the subsequent re-equilibration of the piezometric levels of both aquifers in the vicinity of the inlet and the outlet of the defective seal. Numerical simulations of groundwater circulation around the well support the observed impact of the hydraulic short circuit on the results of the falling-head permeability test. These observations demonstrate that a properly designed falling-head permeability test may be useful in the detection of defective casing seals.

show abstract

“…The resulting short-circuiting or leakage process has been studied at laboratory (Chesnaux and Chapuis, 2007) and field scale (Jiménez-Martínez et al, 2011;Richard et al, 2014), and for deep geological CO 2 storage (Gasda et al, 2008). Santi et al (2006) evaluated tools to investigate cross-contamination of aquifers.…”

Section: Introductionmentioning

confidence: 99%

Consequences and mitigation of saltwater intrusion induced by short-circuiting during aquifer storage and recovery in a coastal subsurface

Zuurbier

Stuyfzand

2017

Hydrol. Earth Syst. Sci.

View full text Add to dashboard Cite

Abstract. Coastal aquifers and the deeper subsurface are increasingly exploited. The accompanying perforation of the subsurface for those purposes has increased the risk of shortcircuiting of originally separated aquifers. This study shows how this short-circuiting negatively impacts the freshwater recovery efficiency (RE) during aquifer storage and recovery (ASR) in coastal aquifers. ASR was applied in a shallow saltwater aquifer overlying a deeper, confined saltwater aquifer, which was targeted for seasonal aquifer thermal energy storage (ATES). Although both aquifers were considered properly separated (i.e., a continuous clay layer prevented rapid groundwater flow between both aquifers), intrusion of deeper saltwater into the shallower aquifer quickly terminated the freshwater recovery. The presumable pathway was a nearby ATES borehole. This finding was supported by field measurements, hydrochemical analyses, and variable-density solute transport modeling (SEAWAT version 4; Langevin et al., 2007). The potentially rapid short-circuiting during storage and recovery can reduce the RE of ASR to null. When limited mixing with ambient groundwater is allowed, a linear RE decrease by short-circuiting with increasing distance from the ASR well within the radius of the injected ASR bubble was observed. Interception of deep short-circuiting water can mitigate the observed RE decrease, although complete compensation of the RE decrease will generally be unattainable. Brackish water upconing from the underlying aquitard towards the shallow recovery wells of the ASR system with multiple partially penetrating wells (MPPW-ASR) was observed. This "leakage" may lead to a lower recovery efficiency than based on current ASR performance estimations.

show abstract

Field evidence of hydraulic connections between bedrock aquifers and overlying granular aquifers: examples from the Grenville Province of the Canadian Shield

Cited by 21 publications

References 15 publications

Scenarios of groundwater chemical evolution in a region of the Canadian Shield based on multivariate statistical analysis

Scenarios of groundwater chemical evolution in a region of the Canadian Shield based on multivariate statistical analysis

Detecting a Defective Casing Seal at the Top of a Bedrock Aquifer

Consequences and mitigation of saltwater intrusion induced by short-circuiting during aquifer storage and recovery in a coastal subsurface

Contact Info

Product

Resources

About