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Injection of Produced Wastewater
Published in Frank R. Spellman, Hydraulic Fracturing Wastewater, 2017
A confined aquifer is sandwiched between two impermeable layers that block the flow of water. The water in a confined aquifer is under hydrostatic pressure. It does not have a free water table (see Figure 10.2). Confined aquifers are referred to as artesian aquifers. Wells drilled into artesian aquifers are artesian wells and commonly yield large quantities of high-quality water. An artesian well is any well where the water in the well casing would rise above the saturated strata. Wells in confined aquifers are normally referred to as deep wells and are not generally affected by local hydrological events. A confined aquifer is recharged by rain or snow in the mountains where the aquifer lies close to the surface. Because the recharge area is some distance from areas of possible contamination, the possibility of contamination is usually very low; however, once contaminated, confined aquifers may take centuries to recover.
Glossary of Terms
Published in Louis Theodore, R. Ryan Dupont, Water Resource Management Issues, 2019
Louis Theodore, R. Ryan Dupont
artesian well: a well tapping a confined aquifer in which the static water level is above the bottom of the upper confining unit; a flowing artesian well is a well in which the water level is above the land surface.
Ground-penetrating Radar and Geotechnical Analyses to Investigate the Foundation Settlements of an Indiana House in NW Spain
Published in International Journal of Architectural Heritage, 2022
Mercedes Solla, José Manuel López-Leira, Alex Alonso-Díaz, Juan Luis Rodríguez
Furthermore, it should be mentioned the existence of a road adjacent to the south façade of the building (1.5 m below the terrace level), with a considerable density of heavy traffic most certainly transmitting vibrations to the structure. It is important to highlight that three upgrading and expansion works were carried out on this road during the last 30 years, supporting strong heavy traffic from 1990 to 2005. Another aspect to take into account is the existence of an artesian well located 8 m away from the northeast corner at the back façade of the building (see Figure 2(b)), whose use was abandoned at the beginning of the 1980s. Figure 2(b) presents a scheme of the well location and the most significant water levels measured, including the water level measured inside the well in different periods and its relation with the ground base level. As will be seen later, in the geotechnical tests carried out on October 27, 2021, the water table was not detected. However, it cannot be excluded the possibility that the ground base is subjected to humidity fluctuations according to the amount of rainfall in each season. These variations in soil moisture content can lead to saturated soils under foundation, and subsequent loss of bearing capacity. Therefore, it will be essential to know the most critical zones of the subsoil from a mechanical-resistance point of view to carry out the geotechnical prospection in order to plan corrective maintenance.
Groundwater level response to the Wenchuan earthquake of May 2008
Published in Geomatics, Natural Hazards and Risk, 2019
There are two types of groundwater level observation wells in mainland China. The first type is the non-artesian well, and the second type is the flowing artesian well (Figure 2). For the non-artesian well, the water level is defined as the distance from the water surface of the borehole to the well head (Figure 2a). In contrast, for the artesian well, the water flow is controlled by a control valve that maintains the water surface within a certain range (i.e. the water surface remains at the axis of the control valve if the flow discharge is too high, or the water will be output from the well head and the water surface remains at the well head if the flow discharge is too low). The water level is defined as the distance between the well water surface and the axis of the valve (Figure 2b).
Numerical modelling in support of a conceptual model for groundwater flow and geochemical evolution in the southern Outaouais Region, Quebec, Canada
Published in Canadian Water Resources Journal / Revue canadienne des ressources hydriques, 2018
Nelly Montcoudiol, John Molson, Jean-Michel Lemieux
In this new conceptual model, vertical flow gradients in the confined aquifer have now been clarified. Specifically, the confined aquifer is now divided into two parts, with the up-gradient area (from km 23 to 24) characterised by upward vertical flow gradients (referred to previously as flowing artesian) whereas the down-gradient part has downward vertical flow gradients. These findings need to be verified against more detailed and reliable data (only one artesian well was found in this part of the confined aquifer). Regardless of the flow gradient directions, groundwater flow is very slow in the clay where chloride transport is dominated by downward diffusion into the fractured bedrock, where it becomes diluted due to rapidly flowing fresh water. Some upward diffusion towards surface fresh water is also suggested.