Well water quality in rural Nicaragua using a low-cost bacterial test and microbial source tracking

Water-related diseases, particularly diarrhea, are major contributors to morbidity and mortality in developing countries. Monitoring water quality on a global scale is crucial to making progress in terms of population health. Traditional analytical methods are difficult to use in many regions of the world in low-resource settings that face severe water quality issues due to the inaccessibility of laboratories. This study aimed to evaluate a new low-cost method (the compartment bag test (CBT)) in rural Nicaragua. The CBT was used to quantify the presence of Escherichia coli in drinking water wells and aimed to determine the source(s) of any microbial contamination. Results indicate that the CBT is a viable method for use in remote rural regions. The overall quality of well water in Pueblo Nuevo, Nicaragua was deemed unsafe, and results led to the conclusion that animal fecal wastes may be one of the leading causes of well contamination. Elevation and depth of wells were not found to impact overall water quality. However rope-pump wells had a 64.1% reduction in contamination when compared with simple wells.

Rope Pump Modifications to Reach Greater Depths: A Service Project for Clean Water in The Gambia

Rope pumps are a locally adaptable and relatively simple technology for water retrieval that are easy to understand and repair and perform well with respect to water quality. Concern Universal - an NGO with offices in Banjul, The Gambia - was introducing the rope pump into The Gambia and needed assistance in designing a rope pump that could lift water from greater depths. Modifications to the rope pump would be needed, which became the basis of an opportunity for a student service-learning project / capstone design experience for students to develop a solution. More specifically, the design criteria were to develop an affordable, easy to use rope pump that could be used to pump water from a depth of 30 m to a storage tank 5 m above ground with a constraint of human power by a single operator. A team of undergraduate students and faculty designed, built and tested a rope pump that was similar to those used in rural Gambian villages. The team’s rope pump design, analyze, build and test process is described in this paper. The design solution began by first modeling the rope pump in a user-defined MATLAB routine to effectively determine the effects of parameters and constraints. A parametric study, where pipe diameter, number of pistons per meter of rope length, well depth and input rotational speeds were varied, was conducted. These results provide a range of conditions for using a rope pump at various depths and provided a basis for designing a pump. Experimental tests were conducted, and the results were compared to theoretical predictions. Experimental results for flow rate were within 3-18% of predicted values. To meet the client’s needs, it was determined that a rope pump with 1.27 cm (0.5 in) diameter piping, two pistons per meter, and a belt drive with gears of ratio of 1.5:1 to increase torque could raise water 35 m using operator under human-power. Additionally, alternative forms of power that would be available to the region are briefly investigated and discussed as potential future work, although further development was beyond the scope of this design project.

Characterisation of the water quality from open and rope-pump shallow wells in rural Cambodia

An 8 month investigation into the quality of water from open and rope-pump shallow wells in rural Cambodia was conducted. Wells were analysed for indicators of the health (arsenic, fluoride, manganese, nitrate, total coliforms, E. coli, male-specific coliphage) and aesthetic (iron, chloride, conductivity, total dissolved solids, hardnesss, turbidity, pH) quality of the water, and referenced to the Cambodian Drinking Water Standard when available. The shallow aquifer was chemically less of a health risk than the deep aquifer; however, microbial contamination was considerable for both shallow well types with mean E. coli loads of 103 CFU/100 mL and male-specific coliphage contamination of 102 PFU/eluate. Temporal variation in microbial contamination was significant (p < 0.05), with overall loads decreasing during the dry season. The aesthetic quality of the water was poor for all samples, but worsened during the dry season. No significant difference was observed in the quality of water from open and rope-pump wells, despite their classification as unimproved and improved respectively by the WHO/UNICEF Joint Monitoring Programme. Contaminants present in both well types may readily be removed by simple water treatment, suggesting that household treatment may be more beneficial to rural Cambodian households than shallow aquifer source improvements.

The case for the rope-pump in Africa: A comparative performance analysis

The conventional handpump is the most popular technology choice for improved potable water supplies in rural sub-Saharan Africa. To date, however, it has failed to deliver satisfactory levels of sustainability, largely due to inadequate maintenance capacity. An alternative option to standardised imported handpumps is the locally manufactured rope-pump, which is considerably cheaper and easier to maintain but has been rejected in the past due to fears of impaired water quality. This paper presents the key aspects of a study in northern Ghana which compared the performance of rope-pumps with that of conventional handpumps, to determine whether or not the rope-pump provides a viable alternative for community water supplies across the sub-continent. User interviews, sanitary surveys, water quality analyses and technical performance measurements were used to develop a comparative performance analysis for the two pump types. The findings of the study indicated that the rope-pump out-performed the conventional handpump on the majority of counts and that, contrary to widespread perceptions, there was no significant difference between pump types with respect to the impact on microbiological water quality. Consequently, the rope-pump provides a significant technological opportunity to improve water supply sustainability in Africa.