Arsenic (As) contamination in groundwater is a severe and adverse water quality issue for drinking purposes, particularly in Southeast Asia, where groundwater is the main drinking water source. Bangladesh is one of the countries where arsenic poisoning in groundwater is massive and it is essential to find out a reliable alternative safe drinking water source. In this process, it is very much needed to identify As-rich wells to avoid drinking water from them and to assess the extent of contamination as well. This study attempts to evaluate the potentiality of tube-well (TW) platform color as low-cost quick screening tool for As and Mn as well in drinking water wells (n=272). The result shows strong association of red color platform with As-rich water in the corresponding wells compared to WHO guideline value of 10 μg/L (98.7% certainty) and regional (Bangladesh/India) standard of 50 μg/L (98.3% certainty). The sensitivity and efficiency of red color platforms to screen high As water in TW for 10 μg/L are 98% and 97%. Similarly, for 50 μg/L, it is 98% for both sensitivity and efficiency. However, because of a very low number (n=4) of TW platform stained with black color, it is not possible to make any conclusion on the potentiality of black color as a screening tool for Mn. This study suggests that red colored platform can be potentially used for primary identification of TWs with elevated As concentration and to prioritise sustainable As mitigation management. However, this study does not discard the concept of black colored platform as a screening tool for Mn-rich water. Further study is recommended to evaluate the efficiency of black color as a screening tool for Mn.

The overall aim of this thesis is to evaluate the risk for increased morbidity and mortality due to long-term arsenic exposure via drinking water by use of epidemiological and spatial approaches in studies performed in Matlab, Bangladesh. A total of 166,934 individuals aged 4 years and above were screened for skin lesions in 2002-2003. Another sample of 115,903 adults aged 15 years or more and a third sample of 26,972 pregnancies in 1991-2000 were considered in a historical cohort and an ecological study, respectively, where risk of adult mortality and spatial clusters of foetal loss and infant death were analysed in relation to arsenic exposure. More than 70% of the tube-wells in the study area exceeded the threshold for arsenic contamination according to the WHO guideline (10 µg/L). The prevalence of arsenic-induced skin lesions was 3/1000 and men had significantly higher prevalence of skin lesions (SMR 158, 95% CI: 133-188) compared to women. There was an increased risk for death in adulthood due to all non-accidental causes (hazards ratio = 1.16, [95% CI 1.06-1.26]) even at a low level of arsenic contamination (10-49 µg/L). Slightly lower risks were observed for death in cancers (1.44 [1.06-1.95]) and infectious diseases (1.30 [1.13-1.49]) at 50-149 µg/L, but for cardiovascular diseases, it was evident (1.23 [1.01-1.51]) from the level 150-299 µg/L. A dose-response relationship was observed for each of these causes. We identified high and low risk clusters of foetal loss and infant death that coincided with identified high and low clusters of arsenic exposure. Water arsenic concentration of the reported main water source was significantly correlated with arsenic concentration in urine, which reflects current arsenic intake from all sources (R2=0.41, ρ< 0.0001), and the influence of neighbouring water sources was minimal. The study findings underlines that the ongoing arsenic exposure has resulted in a series of severe public health consequences in Bangladesh that call for reinforcement in the mitigation efforts. Knowledge about the spatial distribution of exposure and health effects may be of value in that process.

<p>In developing countries water access is not always available. In many locations around the world, people lack sufficient access of water for both drinking and domestic purposes and use unsafe water sources. Particularly in sub-Saharan Africa, women and children walk great distances to obtain access to water. People must have equitable and affordable access to safe and sufficient water that is palatable and in sufficient quantity for both drinking and domestic purposes before any other long-term economic development or social improvement can occur. This research seeks to increase access to subsurface water by improving the driving capabilities of the Well-Driver PUP (Purdue Utility Project) vehicle. The Well-Driver PUP is a low-volume manufactured utility vehicle with a hydraulic post driver mated to it in order to mechanize tube well installation. </p> <p>Worldwide, there are many locations where the water table depth is less than 23 meters, specifically in the 10-20 meters range. These areas include sub-Saharan Africa, the Caribbean, South America, northern India, Asia, and parts of the Asia Pacific Islands. These locations are places where the Well-Driver PUP could potentially be utilized, if sufficient reliability and depth can be demonstrated on a repeatable basis. This would increase the number of locations throughout the world that the vehicle could be used to access ground water for those with limited to no current water access. Ghana is one of the many countries located within sub-Saharan Africa where the Well-Driver PUP could have a positive impact.</p> <p>The author has had significant professional experience working in Ghana on various international development projects related to agriculture, water, sanitation, and hygiene (WASH). She has been part of international development projects in Ghana, Tanzania, and Haiti, with experience working cross-culturally since 2014. She has worked on projects specifically in Ghana for more than 9 years and has been part of more than 32 different water resource projects within the country. Therefore, consideration is specifically given to the appropriateness of the Well-Driver PUP as first piloted in Ghana. For this work, a cost analysis of using the Well-Driver PUP per depth and comparison to current driven wells in Ghana was carried-out. </p> <p>A review of the literature was conducted. Four research questions and experiments were established. Experiment 1 carried-out three different pipe stack numerical loading studies that were simulated in Fusion 360® (Autodesk, San Rafael, CA). Load models were examined of a centered hit, a non-centered hit, and a well point only. It was shown that the average dynamic impact force applied by the driving ram was calculated to be 39 kN. FEA analysis was conducted in Fusion 360®, and it included Von Mises, safety factor, and displacement results. The average dynamic impact force that the Well-Driver PUP applies was less than both the yield stress and ultimate tensile strength of ASTM A53 steel, indicating that no deformation or breakage of the well point should be expected. </p> <p>Experiment 2 included increasing the weight of the driving ram, through the addition of weight plates. A series of wooden fence post installations using these new weight additions was conducted. This experiment allowed for a regression model to be developed predicting the impact of weight added to the driving ram, the drop height of the ram, and the soil moisture content, on the driving depth of the vehicle. The MLR model included the penetration depth (Y), weight added (X₁), drop height (X₂), and soil moisture content (X₃). The model coefficient estimates were determined, and the predictor variables were all found to be significant at p < 0.01.</p> <p>Experiment 3 focused on improved reliability and finding the maximum depth capabilities of the Well-Driver PUP with new weight additions added to the driving ram. Two attempts were made to determine the driving depth capabilities of the vehicle. Both well installations were conducted in Montgomery County Indiana. Water was struck at both locations. At the first location, final well depth was 2.1 m with a 0.76 m of water within the column. The driver encountered a layer of blue-gray clay that it was unable to pass through. </p> <p>A second driving attempt was made to install a deeper well. The final well depth was 5.0 m with 1.67 m of water within the column. At this location, it is believed that a layer of limestone, shale, or siltstone was encountered. Comparing the compressive strength of limestone, sandstone, and shale, the Well-Driver PUP was not capable of driving through such materials. Therefore, at both well locations, the maximum driving depth capabilities of the driver were achieved. At both installation locations, the wells were formally developed. Both sets of water quality samples were submitted to the Montgomery County Health Department and received satisfactory ratings. </p> <p>Experiment 4 resulted in the fabrication and design of a 4” well point. The fabricated well point was installed to create a completed well at a depth of 2.7 m in Linden IN. There was 0.1 m of water within the pipe column. The well was formally developed, and the water quality results received a satisfactory rating. A cost analysis of a 4” well by depth was conducted. The total cost to fabricate one well point totaled $661.42. Of the total cost, 81% of the costs came from the 4” base pipe and the specialty pre-perforated screen used to create the secondary screen. The completion of these experiments provides a better understanding of the driving capabilities of the Well-Driver Pup. Improving the driving depth capabilities of the Well-Driver Pup will help to push this low-cost alternative technology closer to release in the developing world.</p> <p><br></p>