Shallow Hand-dug Wells Research Articles

Socio-economic aspects of domestic groundwater consumption, vending and use in Kisumu, Kenya

Shallow hand-dug wells are commonly used to supplement partial or intermittent piped water coverage in many urban informal settlements in sub-Saharan Africa. Such wells are often microbially contaminated. This study aimed to quantify the amount of such groundwater consumed, identify the socio-economic profile of well owners and consumers, and patterns of domestic water usage in informal settlements in Kisumu, Kenya. Building on a previous study, 51 well owners and 137 well customers were interviewed about well water abstraction, water usage and handling patterns, asset ownership, and service access. An estimated 472 m3 of groundwater per day was abstracted in two informal settlements, with most groundwater consumers using this water for purposes other than drinking or cooking. According to an asset index, well owners were significantly wealthier than both the customers purchasing their groundwater and those drinking or cooking with untreated groundwater. This suggests that shallow groundwater sources provide poorer urban households with a substantial volume of water for domestic purposes other than drinking and cooking. Ongoing challenges are thus to raise awareness of the health risks of such water among the minority of consumers who consume untreated groundwater and find means of working with well owners to manage well water quality.

The suitability of shallow hand dug wells for safe water provision in sub-Saharan Africa: Lessons from Ndola, Zambia

Many informal communities within urban areas in sub-Saharan Africa are heavily reliant on shallow hand-dug wells for water, but these are vulnerable to contamination from a range of sources. This paper assesses the heavy metal contamination and total coliform risk of unprotected shallow wells in Ndola, Zambia – a city struggling with contaminated surface waters from both bacteriological and potential mining waste products. One hundred and twenty three shallow wells were sampled across the Ndola, and these encompassed the three main lithologies of the city. All wells lacked an internal casing, however, some wells did have covers and/or pavements surrounding the wells, albeit of dubious efficacy. Despite the lack of protection, the quality of water used abstracted from these wells generally met the World Health (WHO) guidelines for heavy metals (with the exception of Al) and total coliforms (although, this was highly variable). The quality of shallow well water varied across Ndola relative to the underlying geology, where total recoverable concentrations were typically lowest in granite-gneiss. Dissolved load concentrations were lowest in dolomite-limestone, highlighting the role of aquifer geology in acting as a buffer against metal toxicity. Our study illustrates that shallow wells, within the appropriate geological units, may provide a safe and reliable source of drinking water. Well protection is, however, needed to ensure that the proliferation of shallow well use does not lead to regional degradation of the groundwater resource. There is an immediate need to invest in promoting internal well casing during the construction of shallow wells, concomitant with investment and education into protecting wells at the surface, despite the current relatively low level of contamination in wells without protection.

Water quality awareness and barriers to safe water provisioning in informal communities: A case study from Ndola, Zambia

Abstract Local water providers in developing nations typically view shallow hand-dug wells as traditional and backward sources of water supply. It has long been assumed that the urban poor do not have the ability to develop these in a way that allows them to be classified as ‘improved’ in terms of the Millennium Development Goal for water, believing that users do not understand the factors that constitute safe water and the threats to these sources. Our assessment of the level of environmental knowledge held by local water-users in Ndola in Zambia demonstrates a coherent understanding of the safety of their water sources, the quality of these, the threats to them, and the fundamentals of how their local hydrology works, all of which is contrary to the perspective of key informants who are involved in water supply. Despite their environmental awareness, the majority of users did not generally protect their wells from contamination nor treat their water. The apparent paradox between awareness of risks to water and implementing protection of that water source is a function of the complex suite of socially manifested attitudes, habits and behaviours when it comes to water protection and treatment, which is exacerbated by vulnerable community and family structures and entrenched poverty. For meaningful outcomes in improved access to safe water to be realised providers need to increase their engagement with the informal communities, moving deeper into community-based participatory planning and recognise the societal and cultural factors that are entrained into these communities water supply practices. A key part of this involves the need for providers to move away from simple knowledge-based education to the more holistic form of skill-based health education.

Relationship Between Coliform Bacteria and Water Chemistry in Groundwater Within Gold Mining Environments in Ghana

As in many developing countries, the disease burden from the lack of biologically or chemically safe drinking water is a continuing problem in Ghana. Shallow hand-dug wells and deep boreholes constitute the rural drinking water supply. This is particularly the case in gold mining environments where surface water is commonly contaminated with metalloids and heavy metals. Groundwater samples from 738 wells or boreholes in mining (\(n\,=\,518\)) and non-mining areas (controls, \(n\,=\,220\)) were collected and analyzed to examine the relationship between Escherichia coli (E. coli) and total coliform bacteria, and characteristics such as pH, electrical conductivity, turbidity, total dissolved solids, nitrates, As, Cd, Fe, Mn, and Pb. E. coli and total coliform bacteria, respectively, were detected in 36 and 204 of the 518 groundwater samples in mining locations. E. coli and total coliform bacteria were not detected in any of the groundwater samples collected in non-mining locations. Regression analysis showed that electrical conductivity, As, Cd, Fe, and Pb were significant predictors of E. coli in groundwater in mining areas. Also, regression analysis showed that pH, electrical conductivity, total dissolved solids, turbidity, nitrates, As, and Cd were significant predictors of total coliform bacteria in mining areas. This study demonstrates the need to promptly identify and remediate groundwater sources of drinking water in gold mining communities that potentially have a high risk of disease. It also shows the usefulness of statistical models as tools for guiding local authorities to prevent groundwater contamination.

Quality Assessment of Soil and Groundwater near Kaduna Refinery and Petrochemical Company, Northwest Nigeria

Soil and water are precious natural resources on which rely the sustainability of agriculture, industrialization and the civilization of mankind. Unfortunately, they have been subjected to contamination due to anthropogenic activities leading to the release of heavy metals into the environment. The history of petroleum exploration, exploitation, refining and marketing in Nigeria is a long, complex and painful one in terms of soil and groundwater pollution, which has resulted to multiple environmental and health problems. The study reveals that in some locations near the refinery, the soil and the groundwater are slightly polluted with heavy metals in the order of Fe > As > Zn > Cu > Pb > Cr > Cd > Mn, which may be attributed to the natural enrichment of groundwater through weathering of bedrock in the course of groundwater migration and anthropogenic via dumping of untreated effluents from the refinery and petrochemical into the nearby soil and surface water. The use of groundwater from the shallow hand-dug wells by host communities should be discouraged and alternative source of water should be provided by the company or government. Deep sited boreholes should be sunk to replace the existing Original Research Article Amadi et al.; JSRR, Article no. JSRR.2014.010 885 shallow hand-dug wells in the area. Effluents and waste-water from the refinery and petrochemical should be treated before disposing into the nearby farmlands or surface water.

Studies on Pollution Hazards of Shallow Hand-Dug Wells in Erena and Environs, North-Central Nigeria

This present study evaluates the pollution status of shallow hand-dug wells in Erena community, Shiroro Local Government Area of Niger State, North-central Nigeria using pollution index. The application of pollution index on the hydrochemical data revealed that the groundwater from the shallow aquifers in Erena area had serious bacteriological pollution and moderately/slightly pollution coming from pH, iron and bicarbonate, while the pollution status of the remaining parameters are within the acceptable limit for a potable water. The observed microbial pollution arising from the presence of total coliform and E. coli in the well water are due to migration of plume from un-lined pit-latrines/soakaway while the enrichment of the well water with low pH, high iron and bicarbonate can be attributed to natural sources arising from bedrock dissolution. Results of well water samples collected far away from the pit-latrines/soakaway show no microbial contaminant. The dominant hydrochemical facies as revealed by Piper diagram are Ca-Mg/CO3-HCO3. Boiling of the water before drinking is recommended as most bacteria do not withstand very high temperature. Future hand-dug wells and boreholes in the area should be sited far away from the existing pit-latrines/soakaway and groundwater should be tapped from deeper aquifers. The use of sanitary VIP-latrines and well-lined soakaway system were proposed. Niger State Ministries of Environment and Water Resources should organize workshops and seminars in the area as means of creating the needed awareness on the benefits of good hygiene and clean environment to man.

Suitability assessment of groundwater resources for irrigation around Otte Village, Kwara State, Nigeria

The continuous decline in the quality of available surface water resources due to increasing global pollution threats, put pressure on the need for assessment of suitability of groundwater resources for irrigation purpose. This work assesses the physical and chemical characteristics of the local groundwater resources around the Otte Village, Nigeria, to determine its suitability for irrigation. The methods involve chemical analysis of the water samples obtained from 12 shallow hand-dug wells, and interpretation of the results based on acceptable guidelines. The results of the total dissolved solids (90 - 534 mgL -1 ), Electrical Conductivity (222 - 544 µS/cm), Soluble Sodium Percentage (-1.70 - 150.05 %), Permeability Index (4.15% - 22.57 %), Residual Sodium Bicarbonate (-1.89 - 5.63 meqL -1 ) and Sodium Adsorption Ratio (1.77 - 171.9) obtained for the water samples indicate that the geology appears to have greater influence on the chemical transformation of the groundwater resources, compares to any possible effects due to the anthropogenic activities. This work concludes that the water samples obtained from the areas underlain by the Migmatitic gneiss (W1 - W10) appear to be relatively suitable for irrigation compared with those underlain by the Granitic gneiss (W11 - W12). Further work is required to quantify the effects of the variability of the groundwater quality on the crop yield, as well as to assess any possible effects of the seasonal variations on the conclusions.

Rainwater Harvesting: An Alternative to Safe Water Supply in Nigerian Rural Communities

Rainwater harvesting (RWH) is an economical small-scale technology that has the potential to augment safe water supply with least disturbance to the environment, especially in the drier regions. In Nigeria, less than half of the population has reasonable access to reliable water supply. This study in northeastern Nigeria determined the rate of water consumption and current water sources before estimating the amount of rainwater that can potentially be harvested. A survey on 200 households in four villages namely, Gayama, Akate, Sidi and Sabongari established that more than half of them rely on sources that are susceptible to drought, i.e. shallow hand-dug wells and natural water bodies, while only 3% harvest rainwater. Taraba and Gombe states where the villages are located have a mean annual rainfall of 1,064 mm and 915 mm respectively. Annual RWH potential per household was estimated to be 63.35 m3 for Taraba state and 54.47 m3 for Gombe state. The amount could meet the water demand for the village of Gayama although the other three villages would have to supplement their rainwater with other sources. There is therefore sufficient rainwater to supplement the need of the rural communities if the existing mechanism and low involvement of the villagers in RWH activities could be improved.

Unconfined Aquifer Permeability near hand-dug Wells in the Coastal and Interior dryland of the Libertador General Bernardo O'Higgins Region, Chile

In the dryland of the Libertador General Bernardo O?Higgins Region in Chile, most farmers rely on wide and shallow hand-dug wells as their primary source of water during the dry summer. Few of these wells have sufficient yield for more than domestic use (human consumption, livestock, and irrigation of a subsistence garden). To more accurately assess available groundwater resources, saturated hydraulic conductivity (K) of aquifers in the eight counties that comprise this region?s dryland was estimated using evacuation and recovery tests in 353 hand-dug wells. K followed a log-normal distribution and ranged over nearly five orders of magnitude. County median K varied by a factor of 5 and a slight increasing K trend in the southward direction. In one northern county, less than 4% of the sites had K > 4 m d-1. In the t two southernmost counties, approximately one-quarter of the K values exceeded 4 m d-1. This is approximately the minimum K required for a typical well (1 m diameter and 3 m depth below the water table) to yield 1 L s-1 of water, which is roughly the yield required to irrigate 1 ha. Aquifers located where parent material was predominantly intrusive granite had slightly higher and statistically significant K than those formed predominantly of metamorphic and sedimentary rock. A semi-variogram of K provided weak evidence of a characteristic length scale of approximately 4 km.

Rediscovery and redescription of the unusual subterranean characiform Stygichthys typhlops, with notes on its life history

The rediscovery of the enigmatic subterranean characiform Stygichthys typhlops is reported almost a half-century after the collection of the holotype, the only specimen previously known. Thirty-four specimens were collected in two shallow hand-dug wells at the region of the type locality, c. 13 km south-west of the town of Jaíba, Minas Gerais, Brazil. These specimens provide new information on the morphology of this species, and for the first time on its life history. The conservation status of S. typhlops is discussed. The species is severely threatened by habitat loss caused by exploitation of the aquifer.

Geochemical, isotopic, and remote sensing constraints on the origin and evolution of the Rub Al Khali aquifer system, Arabian Peninsula

Summary Chemical and stable isotopic compositions of groundwater samples from the Rub Al Khali (RAK) in southern Saudi Arabia were analyzed. Samples were collected from wells of variable depth (1.5–800 m) along the perimeter of the eastern half of the RAK including flowing artesian wells, pumped wells (formerly artesian), and shallow hand-dug wells encompassing those in sabkha areas. Data indicate that the water from the artesian and formerly artesian wells represents the contents of confined aquifers. Such water (Group 1) is isotopically depleted (δ2H values ranging from −60‰ to −35‰), and has total dissolved solids (TDS) concentrations ranging from 1300 to 76,000 mg/L, indicating that much of the salinity is acquired in the subsurface. Water from shallow hand-dug wells including those in sabkha areas (Group 2) has experienced significant evaporation (δ2H values ranging from −34‰ to +19‰) as well as salinization (TDS as high as 92,000 mg/L) by dissolution of sabkha salts including halite and gypsum. Stable isotope data for the Group 2 water samples define an evaporation trend line originating from the Group 1 water samples. This relationship indicates that the Group 2-type water evolved from Group 1-type water by ascending through structural discontinuities, dissolving evaporative salts, and undergoing substantial near-surface evaporation in groundwater discharge zones (sabkhas) characterized by shallow groundwater levels (

Afghanistan: An Overview of Ground Water Resources and Challenges

Afghanistan: An Overview of Ground Water Resources and Challenges

The Use of Soil-Gas Sampling in the Study of Groundwater Pollution by Volatile Solvents (VOC): The Example of the Porto Feliz (São Paulo, Brazil) Case

In 1983, a serious accident occurred in Porto Feliz, São Paulo, Brazil when the rupture of a storage tank released 400,000 litres of volatile organic solvents. A large portion of the underlying aquifer was contaminated including some deep wells and shallow hand-dug wells. Soil-gas sampling was the technique used to evaluate the degree and extent of contamination. The method is based on the analysis of small quantities of soil vapors extracted at shallow depths. The origin of these vapors is the underlying contaminated groundwater and the vapor concentration distribution reflects the degree and extent of aquifer contamination. Other techniques were rejected since the physico-chemical characteristics of the pollutants did not allow their detection by traditional geophysical methods and the thick unsaturated zone and difficult geology would have resulted in exorbitant drilling costs for monitoring wells. The use of soil-gas sampling allowed mapping of the pollution plume, defining its two-dimensional shape and location. Vapor analyses at different depths permitted the establishment of concentration gradients and an estimation of vertical vapor flow behavior in the unsaturated zone as well as surface losses by volatilization. Water levels in existing wells made it possible to construct potentiometric surface maps, defining the groundwater flow pattern. Periodic groundwater quality monitoring furnished data for the evaluation of the plume migration velocity and the influence of rainfall on the increase of pollutant concentrations in the aquifer. The groundwater pollutant concentrations obtained gave a good correlation between the two means.