Thesis (Ph. D.)--University of Sydney, 2009. / Title from title screen (viewed November 5, 2009). Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the School of Geosciences in the Faculty of Science. Includes bibliographical references. Also available in print form.

Thesis (Ph. D.)--University of Texas at Austin, 1999. / Vita. Includes bibliographical references (leaves 397-402). Available also in a digital version from Dissertation Abstracts.

Thesis (Ph.D. (Geology))--University of Pretoria, 2000 / Summaries in Afrikaans and English. Includes bibliographical references.

The objective of this study is to improve the understanding of the effect of biofilm growth and biofouling on well performance in a fractured rock aquifer. The study was conducted by investigating biofouling in several recently drilled and much older wells. The study was conducted at three field sites using six groundwater wells in Perth, Portland and Cambridge Ontario. The well located in Perth was drilled in the spring of 2006 and after preliminary hydraulic testing; biofilm was grown in the well by the addition of nutrients (steel wool, Difco beef peptone and gelatin). The wells located in Portland and Cambridge are more than 10 years old and were already biofouled. In each case, the well was hydraulically tested using open- well pumping methods and via slug testing using a straddle packer system (1.7m spacing) in which measurements were obtained contiguously from the bottom to the top of the well. This provided distinct measurements of the hydraulic properties of the individual fracture zones along the length of each hole. The five older wells in Portland and Cambridge were cleaned following the initial testing using recirculation of hydrochloric acid followed by recirculation of 35% hydrogen peroxide. Once the cleaning was completed, the hydraulic testing was repeated. Each of the wells were videotaped using a downhole camera at various stages during the study. Samples were obtained on three occasions for bacterial typing using the BART™ system. Transmissivity data from the different states of fouling (drilled, fouled or cleaned) were compared and it was determined that fractures with low transmissivity values are more susceptible to the effects of biofouling than those with high transmissivity. The reduction in transmissivity was as much as 50% percent. Fractures with low transmissivity are of small apertures which are easily plugged by biofilm. The cleaning process did not markedly improve total wellbore performance for those wells where a comparison was made following cleaning. The presence of any form of iron, (i.e. steel well casing or steel pump parts) in the well will contribute significantly to the biofouling, based on the results of the laboratory study. / Thesis (Master, Civil Engineering) -- Queen's University, 2007-12-11 11:11:24.327

<p>Table Muntain Group has been identified as one of the major Regional Aquifers in South Africa. the vast distribution of it leads to a great diversity in its hydrogeological properties, which influences the dynamics of recharge, discahrge and storage, resulting in groundwater occurrances unevenly distributed in TMG area. Thereby a proper regional groundwater resource evaluation focusing on the quantification of recharge, discharge and storage, is of most importance for the efficient groundwater utilization and management of TMG aquifers.The response of TMG aquifer to pumping stress is studied in Kammanassie Mountains by groundwater flow modeling. 3D hydrogeological model is constructed, which helps to improve the understanding of the conceptual hydrogeological model. Detailed groundwater-related analyses are performed on the basis of previous data sets. Groundwater numerical model is then established according to the conceptual model to stimulate the aquifers responses to various pumping scenarios. Some general data processing approaches are also develooped in this study that can be expected to apply to analog studies.</p>

No description available.

Due to the increasing demand of fresh water in Bandung, the capital city of the west Java Province, the Republic of Indonesia, since 1980's, the municipal government and private firms have started to use deep groundwater through deep wells. This project report investigates the impact of this development on the pattern of deep groundwater flows and the environment by means of a two dimensional computer model. A computer program called AQUIFEM-1 is used. The conceptual model, consisting of a triangular finite element grid with 164 nodes and 289 elements, which represents the study area of about 325 km2. The results are shown either on printing outputs or on graphs that show the changes of the groundwater flow pattern. It is concluded that, the total existing well discharge of about 666 m3/day does change the groundwater flow pattern significantly depleting the volume of the water in the aquifer. This may cause the shallow wells located in the area to dry up, heavy constructions on shallow footings may experience additional settlement, and subsidence over part of the area might occur in time.

<p>Table Muntain Group has been identified as one of the major Regional Aquifers in South Africa. the vast distribution of it leads to a great diversity in its hydrogeological properties, which influences the dynamics of recharge, discahrge and storage, resulting in groundwater occurrances unevenly distributed in TMG area. Thereby a proper regional groundwater resource evaluation focusing on the quantification of recharge, discharge and storage, is of most importance for the efficient groundwater utilization and management of TMG aquifers.The response of TMG aquifer to pumping stress is studied in Kammanassie Mountains by groundwater flow modeling. 3D hydrogeological model is constructed, which helps to improve the understanding of the conceptual hydrogeological model. Detailed groundwater-related analyses are performed on the basis of previous data sets. Groundwater numerical model is then established according to the conceptual model to stimulate the aquifers responses to various pumping scenarios. Some general data processing approaches are also develooped in this study that can be expected to apply to analog studies.</p>

Thesis (M.S. - Geosciences)--University of Arizona. / Includes bibliographical references.

Thesis (Ph. D. - Political Science)--University of Arizona, 1982. / Includes bibliographical references (leaves 342-362).