A Comparison of Borehole and Monitoring Well Groundwater Sample Results Using Both Field and Certified Laboratories: ABSTRACT

Soil vapour intrusion is now commonly evaluated as part of human health risk assessments at contaminated sites where buildings or other structures are located in close proximity to volatile organic chemicals (VOCs) in subsurface soils and groundwater. Investigation of the vapour intrusion pathway often requires that VOC concentrations in the soil gas adjacent to buildings and structures be characterized as part of the risk assessment process. This paper presents the design of a new soil gas monitoring well and a sampling procedure that effectively eliminate concerns about soil gas sample dilution due to short-circuiting of atmospheric air and help to ensure the collection of representative soil gas samples. The results of a parametric numerical modelling study that was applied to address the air short-circuiting issue and the technical rationale for the new soil gas monitoring well (SGMW) design are presented in this paper along with recommended soil gas sampling procedures in various soil conditions. The SGMW design rationale and methodology outlined in this paper considered the effects of soil moisture content and permeability, the depth to the sampling screen interval, and the soil gas sample extraction rate.

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A Downhole Passive Sampling System To Avoid Bias and Error from Groundwater Sample Handling

Environmental Science & Technology ◽

10.1021/es100828u ◽

2010 ◽

Vol 44 (13) ◽

pp. 4917-4923 ◽

Cited By ~ 22

Author(s):

Sanford L. Britt ◽

Beth L. Parker ◽

John A. Cherry

Keyword(s):

Passive Sampling ◽

Groundwater Sample ◽

Sampling System ◽

Sample Handling

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The measurement of groundwater temperature in shallow piezometers and standpipes

Canadian Geotechnical Journal ◽

10.1139/t05-061 ◽

2005 ◽

Vol 42 (5) ◽

pp. 1377-1390 ◽

Cited By ~ 14

Author(s):

Matthew D Alexander ◽

Kerry TB MacQuarrie

Keyword(s):

Finite Element ◽

Statistical Analysis ◽

Transport Model ◽

Shallow Groundwater ◽

Subsurface Temperature ◽

Groundwater Temperature ◽

Monitoring Well ◽

Laboratory Results ◽

The Impact

Accurate measurements of in situ groundwater temperature are important in many groundwater investigations. Temperature is often measured in the subsurface using an access tube in the form of a piezometer or monitoring well. The impact of standpipe materials on the conduction of heat into the subsurface has not previously been examined. This paper reports on the results of a laboratory experiment and a field experiment designed to determine if different standpipe materials or monitoring instrument configurations preferentially conduct heat into the shallow sub surface. Simulations with a numerical model were also conducted for comparison to the laboratory results. Statistical analysis of the laboratory results demonstrates that common standpipe materials, such as steel and polyvinylchloride (PVC), do not affect temperature in the subsurface. Simulations with a finite element flow and heat transport model also confirm that the presence of access tube materials does not affect shallow groundwater temperature measurements. Field results show that different instrument configurations, such as piezometers and water and air filled and sealed well points, do not affect subsurface temperature measurements.Key words: groundwater temperature, temperature measurement, conduction, piezometers, piezometer standpipes, thermal modelling.

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Robust CO2 Plume Imaging Using Joint Tomographic Inversion Of Distributed Pressure And Temperature Measurements

10.2118/206249-ms ◽

2021 ◽

Author(s):

Changqing Yao ◽

Hongquan Chen ◽

Akhil Datta-Gupta ◽

Sanjay Mawalkar ◽

Srikanta Mishra ◽

...

Keyword(s):

Carbon Sequestration ◽

History Matching ◽

Temperature Measurements ◽

Injection Well ◽

Co2 Injection ◽

Pressure Data ◽

Distributed Temperature Sensing ◽

Data Set ◽

Monitoring Well ◽

Co2 Plume

Abstract Geologic CO2 sequestration and CO2 enhanced oil recovery (EOR) have received significant attention from the scientific community as a response to climate change from greenhouse gases. Safe and efficient management of a CO2 injection site requires spatio-temporal tracking of the CO2 plume in the reservoir during geologic sequestration. The goal of this paper is to develop robust modeling and monitoring technologies for imaging and visualization of the CO2 plume using routine pressure/temperature measurements. The streamline-based technology has proven to be effective and efficient for reconciling geologic models to various types of reservoir dynamic response. In this paper, we first extend the streamline-based data integration approach to incorporate distributed temperature sensor (DTS) data using the concept of thermal tracer travel time. Then, a hierarchical workflow composed of evolutionary and streamline methods is employed to jointly history match the DTS and pressure data. Finally, CO2 saturation and streamline maps are used to visualize the CO2 plume movement during the sequestration process. The power and utility of our approach are demonstrated using both synthetic and field applications. We first validate the streamline-based DTS data inversion using a synthetic example. Next, the hierarchical workflow is applied to a carbon sequestration project in a carbonate reef reservoir within the Northern Niagaran Pinnacle Reef Trend in Michigan, USA. The monitoring data set consists of distributed temperature sensing (DTS) data acquired at the injection well and a monitoring well, flowing bottom-hole pressure data at the injection well, and time-lapse pressure measurements at several locations along the monitoring well. The history matching results indicate that the CO2 movement is mostly restricted to the intended zones of injection which is consistent with an independent warmback analysis of the temperature data. The novelty of this work is the streamline-based history matching method for the DTS data and its field application to the Department of Engergy regional carbon sequestration project in Michigan.

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Detection of contaminant plumes released from landfills

Hydrology and Earth System Sciences Discussions ◽

10.5194/hessd-3-819-2006 ◽

2006 ◽

Vol 3 (3) ◽

pp. 819-857

Author(s):

N. B. Yenigül ◽

A.T. Hendsbergen ◽

A. M. M. Elfeki ◽

F. M. Dekking

Keyword(s):

Simulation Model ◽

Contaminant Transport ◽

Analytical Model ◽

Detection Probability ◽

Average Concentration ◽

Contaminant Plume ◽

Contaminant Plumes ◽

Heterogeneous Aquifer ◽

Monitoring Well ◽

Detection Probabilities

Abstract. Contaminant leaks released from landfills are a significant threat to groundwater quality. The groundwater detection monitoring systems installed in the vicinity of such facilities are vital. In this study the detection probability of a contaminant plume released from a landfill has been investigated by means of both a simulation and an analytical model for both homogeneous and heterogeneous aquifer conditions. The results of the two models are compared for homogeneous aquifer conditions to illustrate the errors that might be encountered with the simulation model. For heterogeneous aquifer conditions contaminant transport is modelled by an analytical model using effective (macro) dispersivities. The results of the analysis show that the simulation model gives the concentration values correctly over most of the plume length for homogeneous aquifer conditions, and that the detection probability of a contaminant plume at given monitoring well locations match quite well. For heterogeneous aquifer conditions the approximating analytical model based on effective (macro) dispersivities yields the average concentration distribution satisfactorily. However, it is insufficient in monitoring system design since the discrepancy between the detection probabilities of contaminant plumes at given monitoring well locations computed by the two models is significant, particularly with high dispersivity and heterogeneity.

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