The hydrogeological and contaminant-transport properties of fractured Champlain Sea clay in Eastern Ontario. Part 1. Hydrogeological properties

Hydrogeological and geochemical investigations were conducted on four fractured Champlain Sea clay deposits in Eastern Ontario. The results from water level monitoring, maximum seasonal variations, and hydraulic head profiles revealed a hydraulically active fractured zone existing at all four sites. The depth of this fractured zone varies from site to site, ranging from 3.2 to 6.0 m. Slug test analysis indicated that bulk hydraulic conductivity values in the upper fractured zone range from 1.8 × 10−8 to 2.0 × 10−5 m/s. In contrast, the measured hydraulic conductivity values from the deepest piezometers range from 8.2 × 10−10 to 1.4 × 10−9 m/s. The geochemical analysis indicated the presence of three hydrochemical facies: a shallow "active" facies, a deep "inactive" facies, and an intermediate "transition" facies. The presence of tritiated groundwater well below the groundwater table indicates that the upper fractured zone at all four sites is hydraulically active. Key words : fractures, Champlain Sea clay, in situ testing, hydrogeology, geochemistry, hydraulic conductivity.

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The hydrogeological and contaminant-transport properties of fractured Champlain Sea clay in eastern Ontario. Part 1. Hydrogeological properties

International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts ◽

10.1016/0148-9062(96)87492-4 ◽

1996 ◽

Vol 33 (1) ◽

pp. A19

Keyword(s):

Transport Properties ◽

Contaminant Transport ◽

Hydrogeological Properties ◽

Eastern Ontario

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Spatial Variability of Contaminant Transport in a Fractured Till, Avedøre Denmark

Hydrology Research ◽

10.2166/nh.1999.0019 ◽

1999 ◽

Vol 30 (4-5) ◽

pp. 333-360 ◽

Cited By ~ 29

Author(s):

Larry McKay ◽

Johnny Fredericia ◽

Melissa Lenczewski ◽

Jørn Morthorst ◽

Knud Erik S. Klint

Keyword(s):

Hydraulic Conductivity ◽

Spatial Variability ◽

Field Experiment ◽

Contaminant Transport ◽

Tracer Test ◽

Conductivity Measurements ◽

Fine Grained ◽

Downward Migration ◽

Rapid Transport ◽

High Degree

A field experiment shows that rapid downward migration of solutes and microorganisms can occur in a fractured till. A solute tracer, chloride, and a bacteriophage tracer, PRD-1, were added to groundwater and allowed to infiltrate downwards over a 4 × 4 m area. Chloride was detected in horizontal filters at 2.0 m depth within 3-40 days of the start of the tracer test, and PRD-1 was detected in the same filters within 0.27 - 27 days. At 2.8 m depth chloride appeared in all the filters, but PRD-1 appeared in only about one-third of the filters. At 4.0 m depth chloride appeared in about one-third of the filters and trace amounts of PRD-1 were detected in only 2 of the 36 filters. Transport rates and peak tracer concentrations decreased with depth, but at each depth there was a high degree of variability. The transport data is generally consistent with expectations based on hydraulic conductivity measurements and on the observed density of fractures and biopores, both of which decrease with depth. Transport of chloride was apparently retarded by diffusion into the fine-grained matrix between fractures, but the rapid transport of PRD-1, with little dispersion, indicates that it was transported mainly through the fractures.

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Laboratory and In Situ Determination of Hydraulic Conductivity and Their Validity in Transient Seepage Analysis

Water ◽

10.3390/w13081131 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1131

Author(s):

Soonkie Nam ◽

Marte Gutierrez ◽

Panayiotis Diplas ◽

John Petrie

Keyword(s):

Hydraulic Conductivity ◽

Field Measurements ◽

Natural Soil ◽

In Situ Tests ◽

Seepage Analysis ◽

Soil Deposits ◽

Seepage Modeling ◽

Sample Disturbance

This paper critically compares the use of laboratory tests against in situ tests combined with numerical seepage modeling to determine the hydraulic conductivity of natural soil deposits. Laboratory determination of hydraulic conductivity used the constant head permeability and oedometer tests on undisturbed Shelby tube and block soil samples. The auger hole method and Guelph permeameter tests were performed in the field. Groundwater table elevations in natural soil deposits with different hydraulic conductivity values were predicted using finite element seepage modeling and compared with field measurements to assess the various test results. Hydraulic conductivity values obtained by the auger hole method provide predictions that best match the groundwater table’s observed location at the field site. This observation indicates that hydraulic conductivity determined by the in situ test represents the actual conditions in the field better than that determined in a laboratory setting. The differences between the laboratory and in situ hydraulic conductivity values can be attributed to factors such as sample disturbance, soil anisotropy, fissures and cracks, and soil structure in addition to the conceptual and procedural differences in testing methods and effects of sample size.

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Reply [to “Comment on “In situ method for estimating subsurface unsaturated hydraulic conductivity” by Uri Shani and Dani Or”]

Water Resources Research ◽

10.1029/96wr00676 ◽

1996 ◽

Vol 32 (6) ◽

pp. 1897-1897

Author(s):

Dani Or ◽

Uri Shani

Keyword(s):

Hydraulic Conductivity ◽

In Situ Method ◽

Unsaturated Hydraulic Conductivity

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Effect of temperature on streambed vertical hydraulic conductivity

Hydrology Research ◽

10.2166/nh.2013.021 ◽

2013 ◽

Vol 45 (1) ◽

pp. 89-98 ◽

Cited By ~ 4

Author(s):

Weihong Dong ◽

Gengxin Ou ◽

Xunhong Chen ◽

Zhaowei Wang

Keyword(s):

Hydraulic Conductivity ◽

Water Temperature ◽

Sediment Cores ◽

Effect Of Temperature ◽

In Situ Tests ◽

Effect Of Water ◽

Vertical Hydraulic Conductivity ◽

Increasing Trend ◽

Streambed Vertical Hydraulic Conductivity

In this study, in situ and on-site permeameter tests were conducted in Clear Creek, Nebraska, USA to evaluate the effect of water temperature on streambed vertical hydraulic conductivity Kv. Fifty-two sediment cores were tested. Five of them were transferred to the laboratory for a series of experiments to evaluate the effect of water temperature on Kv. Compared with in situ tests, 42 out of the 52 tests have higher Kv values for on-site tests. The distribution of water temperature at the approximately 50 cm depth of streambed along the sand bar was investigated in the field. These temperatures had values in the range 14–19 °C with an average of 16 °C and had an increasing trend along the stream flow. On average, Kv values of the streambed sediments in the laboratory tests increase by 1.8% per 1 °C increase in water temperature. The coarser sandy sediments show a greater increase extent of the Kv value per 1 °C increase in water temperature. However, there is no distinct increasing trend of Kv value for sediment containing silt and clay layers.

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Decrease in Hydraulic Conductivity of a Paddy Field using Biocalcification in situ

Geomicrobiology Journal ◽

10.1080/01490451.2015.1081308 ◽

2016 ◽

Vol 33 (8) ◽

pp. 690-698 ◽

Cited By ~ 2

Author(s):

Kağan Eryürük ◽

Daisuke Suzuki ◽

Shin'ya Mizuno ◽

Tetsuji Akatsuka ◽

Takayuki Tsuchiya ◽

...

Keyword(s):

Hydraulic Conductivity ◽

Paddy Field

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Estimation and Scaling of the Near-Saturated Hydraulic Conductivity

Hydrology Research ◽

10.2166/nh.1999.0010 ◽

1999 ◽

Vol 30 (3) ◽

pp. 177-190 ◽

Cited By ~ 1

Author(s):

Per Atle Olsen

Keyword(s):

Hydraulic Conductivity ◽

Saturated Hydraulic Conductivity ◽

Scaling Analysis ◽

Laboratory Measurements ◽

Estimation Errors ◽

Geometric Means ◽

Top Soil ◽

Structured Soils ◽

Order Of Magnitude

The hydraulic conductivity in structured soils is known to increase drastically when approaching saturation. Tension infiltration allows in situ infiltration of water at predetermined matric potentials, thus allowing exploration of the hydraulic properties near saturation. In this study, the near saturated (ψ≥-0.15 m) hydraulic conductivity was estimated both in the top- and sub-soil of three Norwegian soils. A priory analysis of estimation errors due to measurement uncertainties was conducted. In order to facilitate the comparison between soils and depths, scaling analysis was applied. It was found that the increase in hydraulic conductivity with increasing matric potentials (increasing water content) was steeper in the sub-soil than in the top-soil. The estimated field saturated hydraulic conductivity was compared with laboratory measurements of the saturated hydraulic conductivity. The geometric means of the laboratory measurements was in the same order of magnitude as the field estimates. The variability of the field estimates of the hydraulic conductivity from one of the soils was also assessed. The variability of the field estimates was generally smaller than the laboratory measurements of the saturated hydraulic conductivity.

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