Deep aquifers

Nevertheless, an anaerobic system may be the method of choice under certain conditions (/) contamination with compounds that degrade only or better under anaerobic conditions, (2) low yield aquifers that make pump and treat methods or oxygen and nutrient distribution impractical, (J) mixed waste contamination where oxidizable compounds drive reductive dehalogenation of chlorinated compounds, or (4) deep aquifers that make oxygen and nutrient distribution mote difficult and cosdy. 

Olson, G.J.H., Dockins, W.C., McFeters, G.A., and Iverson, W.P., Sulphate-reducing and methanogenic bacteria from deep aquifers in Montana, Geomicrobial. J., 2, 327-340, 1981. 

Xu T., Apps J.A., et al. Numerical simulation of C02 disposal by mineral trapping in deep aquifers. 2004 Applied Geochemistry 19 917-936. 

RCHRG DP Deep aquifer percolation fraction. It represents the fraction of percolation from the root zone which recharges the deep aquifer. This parameter may vary between 0 and 1. 

Fig. 4. Reduced water levels (RWL, in m relative to Australian Height Datum) in shallow aquifer at Site I compared to historical data (a), and in deep aquifer at Site J shown with temperature (b).

Potential for contamination of deep aquifers in Bangladesh by pumping-induced migration of higher arsenic waters... 

Law, D. H-S. and Bachu, S. (1996). Hydrogeological and numerical analysis of C02 disposal in deep aquifers in the Alberta sedimentary basin. Energy Conversion and Management, 37 (6), 1167-1174. 

Shallow ground-waters follow the same pattern, but waters from deep aquifers, geothermal waters, ice cores, etc. can and do lie well off the line. 

When selecting a site for an injection well, it is crucial to understand the hydro-geological conditions to ensure any existing or potential fresh water supplies do not become contaminated. Potable aquifers are more likely to be found at shallower depths, while deep aquifers are more likely to be lower in quality and are less likely to be used as a water source (Mickley 2006). Siting injection wells away from areas known to by seismically active also helps to reduce the possibility of contaminating aquifers. The use of injection wells should also be avoided near recoverable resources like ores, coal, oil and gas (Mickley 2006). The selected receiving aquifer must be able to contain the volume of concentrate for the expected life of the plant (Chelme-Ayala et al. 2009). 

Monitoring the well for leaks and nearby aquifers for contamination must also be considered. The extent of monitoring will vary based on the applicable environmental regulations and nearby potable aquifers. Monitoring wells can be constructed to monitor shallow or deep aquifers, and the cost of a these wells is determined by the required depth and the geology of the site. Additional costs include ancillary surface equipment and alarm systems (Mickley 2006). 

Reductive biotransformation of a contaminant can occur when the contaminant serves as the terminal electron acceptor. Many contaminants that are recalcitrant to bio-oxidation will undergo reductive biotransformations. These biotransformations can lead to detoxification, mineralization, or changes in the mobility of the targeted contaminant. Hexavalent chromium and tetra-chloroethene (PCE) have been investigated as candidates for reductive biotransformation. This technology may be most applicable for in situ remediation for the following scenarios PCE contamination, low-yield aquifers, areas contaminated by both alkylbenzenes and chlorinated ethenes, and deep aquifer contamination. 

This review article summarizes the factors that influence the storage of C02 in deep aquifers. A case study of expected mineral-brine-C02 reactions in the Rose Run Sandstone, a deep aquifer and oil- and gas-containing formation in the Appalachian Basin area of eastern Ohio, USA, is presented. Geochemical reactions between C02, brine, and formation minerals are emphasized in the example because these reactions determine the ultimate fate of C02. 

Peak Gas Production from Deep Aquifer Gas Storage by Horizontal Well" K. Homann, VEW Energie AG, H.J. Kretzschmar, DBI CTUT Gmbh, 20th World Gas Conference. Copenhagen, 10-13 June 1997. 

JICA (Japan International Cooperation Agency) (2002). The Study on the Ground Water Development of Deep Aquifers for Safe Drinking Water Supply to Arsenic Affected Areas in Western Bangladesh. Draft final report, Japan International Cooperation Agency, Kokusai Kogyo and Mitsui Mineral Development Engineering. 

Compaction caused by the weight of overlying rocks is called upon to explain the water pressure in deep-seated artesian aquifers (Mazor, 1995). Compaction counteracts through-flow in deep aquifers, as it causes collapse features, and pressurizes the entrapped water. If through-flow would take place, the open ends of the hypothetical aquifer ducts would serve as... 

Example A local shallow water has been observed to contain 65 pmc and 5 TU. A sample from an adjacent deep well, in similar rocks, revealed 20 pmc and 0 TU. What is the deduced age of the water in the second well The value of 65 pmc may be taken as the initial 14C concentration of the groundwater when it first reached the deep aquifer. The observed 20 pmc represents 20 x 100/65 = 30.7% of the initial value, indicating an age of 9000 years (Fig. 11.1)... 

Blavoux B., Dray M., Fehri A., Ohve P., GroeningM., Sonntag C., Hauquin J. P., Pelissier G., and Pouchan P. (1993) Palaeoclimate and hydrodynamic approach to the Aquitaine Basin deep aquifer (France) by means of environmental isotopes and noble gases. In Isotope Techniques in the Study of Past and Current Environmental Changes in the Hydrosphere and the Atmosphere. IAEA, Vienna, pp. 293-305. 

Cresswell R. G., Bauld J., Jacobson G., Khadka M. S., Jha M. G., ShresthaM. P., and Regmi S. (2001) A hrst estimate of ground water ages for the deep aquifer of the Kathmandu Basin, Nepal, using the radioisotope chlorine-36. Ground Water 39, 449-457. 

Wei H. F., Ledoux E., and de Marsily G. (1990) Regional modeling of groundwater flow and salt and environmental tracer transport in deep aquifers in the Paris Basin. J. Hydrol. 120, 341-358. 

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