Faecal contamination pathways of shallow groundwater in low-income urban areas: implications for water resource planning and management

Shallow groundwater is vulnerable to faecal contamination, especially in low-income urban areas where use of on-site sanitation facilities is high. This paper explores statistical relationships between potential factors influencing contaminant pathways (i.e., variables) and observed faecal contamination of shallow groundwater, represented by nitrate concentrations and counts of Escherichia coli (i.e., response function) in a small, growing town in Uganda over dry and wet seasons in 2018 and 2019. A statistically significant (p = 0.004) multiple linear regression model from dry-season E. coli counts in 2018 identifies medium sanitary risk levels and modes of construction as significant pathways (p = 0.01). Water source depth (10 m) to a pit latrine were also significant (p<0.05) in both hydrogeological formations. No significant linear regression models were established for NO3 during both seasons due to low pH and rapid infiltration velocities; incon-sistent sample timing during the wet season impaired the significance of the statistical models of E. coli counts. We show that modes of construction of water sources and pit latrines play key roles in determining the quality of the shallow groundwater in urban environments. Greater emphasis is therefore required to improve the functionality and sustainability of on-site water sources and pit latrines

WASH conditions in a small town in Uganda: how safe are on-site facilities?

Inadequate hygiene coupled with the conjunctive use of the shallow subsurface as both a source of water and repository of faecal matter pose substantial risks to human health in low-income countries undergoing rapid urbanisation. To evaluate water, sanitation and hygiene (WASH) conditions in a small, rapidly growing town in central Uganda (Lukaya) served primarily by on-site water supply and sanitation facilities, water-point mapping, focus group discussions, sanitary-risk inspections and 386 household surveys were conducted. Household surveys indicate high awareness (82%) of domestic hygiene (e.g. handwashing, boiling water) but limited evidence of practice. WHO Sanitary Risk Surveys and Rapid Participatory Sanitation System Risk Assessments reveal further that community hygiene around water points and sanitation facilities including their maintenance is commonly inadequate. Spot sampling of groundwater quality shows widespread faecal contamination indicated by enumerated thermo-tolerant coliforms (TTCs) (Escherichia coli) ranging from 0 to 104 cfc/100 mL and nitrate concentrations that occasionally exceed 250 mg/L. As defined by the WHO/UNICEF Joint Monitoring programme, there are no safely managed water sources in Lukaya; ∼55% of improved water sources comprising primarily shallow hand-dug wells show gross faecal contamination by E. coli; and 51% of on-site sanitation facilities are unimproved. Despite the critical importance of on-site water supply and sanitation facilities in low-income countries to the realisation of UN Sustainable Goal 6 (access to safe water and sanitation for all by 2030), the analysis highlights the fragility and vulnerability of these systems where current monitoring and maintenance of communal facilities are commonly inadequate

Key factors affecting performance of biogas latrines in urban informal areas: Case of Kampala and Nairobi, East Africa

Large scale application of biogas latrine technology in developing countries faces technical, socioeconomic and financial  challenges. As a result, harnessing its full potential has not been realized. This study examined variables describing the design, construction, operation and maintenance of nineteen biogas latrines in  relation to their performance in Kampala and Nairobi, based on survey and field observations. Pre-tested questionnaires were administered to users, owners and construction  technicians/masons of the biogas latrines. Field observations were also undertaken to assess physical conditions of the biogas latrines. Principal component analysis was then used to establish correlation between variables of design, construction, operation and maintenance in relation to the performance of biogas latrines in terms of burning hours in a day. The design types of all the studied biogas latrine digesters were found to be of fixed dome. Co-digestion of human excreta and cow dung increased the number of biogas burning hours in a day from 0.5 to 1.1. The findings also show that the performance of the biogas latrines was influenced by six of the variables examined describing construction, operation and maintenance: skills of masons, use of standards in construction, training of users on operation and maintenance aspects, number of users/owners and their motivation for installation of biogas plants and physical conditions of the biogas latrines. This  implies that the use of skilled masons,  comprehensive training of users on operation and maintenance aspects and use of cosubstrates are key variables for optimal performance of biogas latrines.Key words: Biogas latrines, Kampala, Nairobi, performance

Household drinking water characteristics in a peri-urban community: the case of Kifumbira Zone, Kampala, Uganda

A study to determine the drinking water quality improvement practises at household level was undertaken in Kifumbira Zone, a Kampala peri-urban area, Uganda. The socio-economic conditions of 150 households were identified using questionnaires and in-depth interviews. Solar water disinfection (SODIS) was introduced to 10 households and water from their boiled drinking water and SODIS treated water was monitored for three months. The social survey indicated that boiling was the most common method applied to improve the drinking water quality – mainly using charcoal and electricity. 65% of the respondent households boiled their drinking water, while the rest consumed it unboiled due to the high cost of charcoal. The raw water sources exhibited microbiological contamination as evidenced by the presence of thermotolerant coliforms and high risk scores on the sanitary inspections conducted. There was a statistically significant difference (p<0.05; n=15) in the mean count of thermotolerant coliforms for boiled and SODIS treated water

In-situ fluorescence spectroscopy is a more rapid and resilient indicator of faecal contamination risk in drinking water than faecal indicator organisms

Faecal indicator organisms (FIOs) are limited in their ability to protect public health from the microbial contamination of drinking water because of their transience and time required to deliver a result. We evaluated alternative rapid, and potentially more resilient, approaches against a benchmark FIO of thermotolerant coliforms (TTCs) to characterise faecal contamination over 14 months at 40 groundwater sources in a Ugandan town. Rapid approaches included: in-situ tryptophan-like fluorescence (TLF), humic-like fluorescence (HLF), turbidity; sanitary inspections; and total bacterial cells by flow cytometry. TTCs varied widely in six sampling visits: a third of sources tested both positive and negative, 50% of sources had a range of at least 720 cfu/100 mL, and a two-day heavy rainfall event increased median TTCs five-fold. Using source medians, TLF was the best predictor in logistic regression models of TTCs ≥10 cfu/100 mL (AUC 0.88) and best correlated to TTC enumeration (ρs 0.81), with HLF performing similarly. Relationships between TLF or HLF and TTCs were stronger in the wet season than the dry season, when TLF and HLF were instead more associated with total bacterial cells. Source rank-order between sampling rounds was considerably more consistent, according to cross-correlations, using TLF or HLF (min ρs 0.81) than TTCs (min ρs 0.34). Furthermore, dry season TLF and HLF cross-correlated more strongly (ρs 0.68) than dry season TTCs (ρs 0.50) with wet season TTCs, when TTCs were elevated. In-situ TLF or HLF are more rapid and resilient indicators of faecal contamination risk than TTCs

Sanitation in informal settlements in East Africa (3ksan)

Improving access to sanitation in slums in East Africa is a challenge. The 3ksan project has been working to identify the barriers and catalysts to sanitation in Kigali, Kampala and Kisumu. Household surveys in the informal settlements in these three cities have provided insight into the different levels of service provision and demand, access to financial services, and perceptions of enforcement of the regulations. This paper presents key results from the household survey, highlighting the different challenges in the three cities

Socio-Institutional Drivers of Groundwater Contamination Hazards: The Case of On-Site Sanitation in the Bwaise Informal Settlement, Kampala, Uganda

This is a research article which contributes to the development of a socio-institutional assessment framework based on a case study of contamination by on-site sanitation (OSS) in an informal settlement of Bwaise (Kampala, Uganda).Socio-institutional factors are poorly addressed in the risk assessment of groundwater contamination. This paper contributes to the development of a socio-institutional assessment framework based on a case study of contamination by on-site sanitation (OSS) in an informal settlement of Bwaise (Kampala, Uganda). We conducted a snapshot survey of the recent extent of groundwater contamination by OSS using microbial and hydro-chemical indicators. Through transition arenas and key informant interviews, we investigated the socio-institutional drivers of the contamination. Overall, 14 out of the 17 sampled groundwater sources tested positive for Escherichia coli during the wet season. Nitrate concentrations at four sources exceeded the World Health Organization guideline value (50 mg/L), attributed to OSS. Despite the high contamination, the community highly valued groundwater as an alternative to the intermittent municipal water supply. We deduced six drivers of groundwater contamination, including land-use management, user attributes, governance, infrastructure management, groundwater valuation, and the operating environment (“LUGIVE”). Qualitative indicators for each of the drivers were also construed, and their interlinkages presented in a causal loop diagram, representing a socio-institutional assessment framework. The framework can help policymakers and the community to analyze various socio-institutional control levers to reduce the risk of groundwater contamination by OSS in informal settlements

Making energy efficiency pro-poor : insights from behavioural economics for policy design

This paper reviews the current state of behavioural economics and its applications to energy efficiency in developing countries. Taking energy efficient lighting in Ghana, Uganda and Rwanda as empirical examples, this paper develops hypotheses on how behavioural factors can improve energy efficiency policies directed towards poor populations. The key argument is that different types of affordability exist that are influenced by behavioural factors to varying degrees. Using a qualitative approach, this paper finds that social preferences, framing and innovative financing solutions that acknowledge people’s mental accounts can provide useful starting points. Behavioural levers are only likely to work in a policy package that addresses wider technical, market and institutional barriers to energy efficiency. More research, carefully designed pre-tests and stakeholder debates are required before introducing policies based on behavioural insights. This is imperative to avoid the dangers of nudging