Large-scale survey of seasonal drinking water quality in Malawi using in situ tryptophan-like fluorescence and conventional water quality indicators

Faecally-contaminated drinking water is a risk to human health, with the greatest risks to those living in developing countries. UN Sustainable Development Goal 6 aims to address this issue. Tryptophan-like fluorescence (TLF) shows potential as a rapid method for detecting microbial contamination in drinking water, which could reduce the spread of waterborne diseases. This study is the first to investigate the effectiveness of TLF for a large-scale survey using a randomised, spot-sampling approach. The large-scale survey took place in Malawi, sub-Saharan Africa, in the dry season (n = 183). A subset of sources were revisited at the end of the following wet season (n = 41). The effectiveness of TLF was assessed by comparing TLF results to thermotolerant coliforms (TTC), humic-like fluorescence (HLF), inorganic hydrochemical data and sanitary risk scores. The most prominent differences in microbial water quality were observed between source types, with little variation between districts and seasons. TLF, TTCs, turbidity and sanitary risk scores were all elevated at alternative sources (shallow wells and tap stands) compared to hand-pumped boreholes. In the dry season, 18% of hand-pumped boreholes showed TTC contamination, which increase to 21% in the wet season. Groundwater recharge processes are likely responsible for seasonal variability of inorganic hydrochemistry at hand-pumped boreholes. TLF was able to distinguish no and low WHO risk classes (TTC 0–9 cfu/100 mL) from medium, high and very high risk classes (TTC 10 – >1000 cfu/100 mL). TLF failed to distinguish between no and low risk classes, which limits the use of TLF for assessing water quality to drinking water standards. This dataset indicates that HLF may raise baseline TLF for samples with low TLF values, increasing false positives. Therefore, TLF is better suited as a rapid high-level water quality screening tool to assess moderate and high levels of faecal contamination

Tryptophan-like fluorescence as a high-level screening tool for detecting microbial contamination in drinking water

Regular monitoring of drinking water quality is vital to identify contamination of potable water supplies. Testing for microbial contamination is important to prevent transmission of waterborne disease, but establishing and maintaining a water quality monitoring programme requires sustained labour, consumables and resources. In low resource settings such as developing countries, this can prove difficult, but measuring microbial contamination is listed as a requirement of reaching the UN's Sustainable Development Goal 6 for water and sanitation. A nine-month water quality monitoring programme was conducted in rural Malawi to assess the suitability of tryptophan-like fluorescence (TLF), an emerging method for rapidly detecting microbial contamination, as a drinking water quality monitoring tool. TLF data was compared with thermotolerant coliforms (TTCs, E. coli) and inorganic hydrochemical parameters. A large (n = 235) temporal dataset was collected from five groundwater drinking water sources, with samples collected once or twice weekly depending on the season. The results show that TLF can indicate a broader contamination risk but is not as sensitive to short term variability when compared to other faecal indicators. This is likely due to a broad association of TLF with elevated DOC concentrations from a range of different sources. Elevated TLF may indicate preferential conditions for the persistence of TTCs and/or E. coli, but not necessarily a public health risk from microbial contamination. TLF is therefore a more precautionary risk indicator than microbial culturing techniques and could prove useful as a high-level screening tool for initial risk assessment. For widespread use of TLF to be successful, standardisation of TLF values associated with different levels of risk is required, however, this study highlights the difficulties of equating TLF thresholds to TTCs or E. coli data because of the influence of DOC/HLF on the TLF signal

To what extent does community management ensure good functionality of groundwater supplies in rural Africa?

Within rural Africa, communal boreholes fitted with handpumps (HPBs) are likely to remain the main source of improved water supplies for decades to come. Understanding how the performance of these supplies can be improved will be central to achieving improved water security. The functionality of community HPBs relies on a range of elements which include not only groundwater resource availability, correct siting and construction of the borehole and handpump mechanism, but also equitable and enabling management arrangements. Since the 1980s – the first UN ‘Water Decade’ – Community Based Management (CBM) has been the policy prescription par excellence for operationalising participatory development in the rural water supply sector. The cornerstone of the CBM model is the creation of a local water point committee or similar community organisation, which is charged with the operation and maintenance of the borehole. Despite its popularity and endurance, there is a relative lack of evidence on how the management capacity of communities relates to the functionality of their boreholes, and a growing recognition among development practitioners and academics that CBM of rural water supply has struggled to deliver on many of its promises. Here we present the findings from a survey of six hundred communities across rural Ethiopia, Uganda and Malawi to examine the extent to which community water management capacity is related to borehole functionality. The capacity of water management arrangements (WMA) was assessed according to four dimensions: finance system; affordable maintenance and repair; decision making, rules, and leadership; and external support. HPB performance was assessed using on a nuanced definition of borehole functionality, which captures different tiers of functionality from a simple binary ‘yes/no’ working, to capturing the level of functionality performance and reliability. The findings reveal that whilst over two thirds of WMA are of medium to high capacity in communities, there is no strong relationship between the WMA capacity and the functionality of the borehole. Of the four management dimensions, affordable maintenance and repair was the best predictor of borehole functionality. However, the capacity of this dimension was seen to be lowest overall, with nearly two thirds of sites having weak or non-existent capacity in this respect. These findings provide evidence to support the growing claim that, in many instances, CBM by itself does not ensure improved functionality performance

Evidence, ideology, and the policy of community management in Africa

This study examines the performance of the policy of community management for rural groundwater supply in Africa. Across the continent, policies that promote community management have dominated the rural water supply sector for decades. As a result, hundreds of thousands of village-level committees have been formed to manage community boreholes equipped with handpumps. With a significant proportion of these handpumps non-functional at any one time, increasing effort is targeted toward understanding the interacting social and physical determinants of this 'hidden crisis'. We conducted a survey of community management arrangements across six hundred sites in rural Ethiopia, Malawi, and Uganda, examining the extent to which management capacity is related to borehole functionality whilst accounting for a range of contextual variables. The capacity of water management arrangements (WMAs) was assessed according to four dimensions: finance system; affordable maintenance and repair; decision making, rules, and leadership; and external support. The survey reveals that 73.3% of WMAs have medium or high capacity. However, we found no strong relationship between the capacity of the WMA and the functionality of the borehole. Of the four management dimensions, affordable maintenance and repair was the best predictor of borehole functionality. However, the capacity of this dimension was seen to be the lowest overall, with 61.9% of sites weak or non-existent. Our results provide very limited support for the policy of community management, and we suggest that evidence alone has not accounted for its persistence over decades. After a short historical analysis, we conclude that explanation for the endurance of this model can be found in the nexus between evidence, ideology, and policy. We argue that it is this same nexus that will likely ensure the popularity of community management for some time to come, despite new ideas and evidence to the contrary