Browsing by Author "Kenan, Okurut"

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Abating eutrophication on urban lakes: a case study of Kabaka's Lake, Uganda
(IWA Publishing Water Practice & Technology, 2023-07) Anne, Nakagiri; Abel, Mutyaba; Charles, Onyutha; Kenan, Okurut
Eutrophication of water bodies is a challenge in many urban areas. This study measured and modelled quantitatively the pollutant nutrient load of an urban lake (80,596 m2), and assessed both external (constructed wetland) and internal (dredging) eutrophication extenuation measures. For the past 25 years, there has been redistribution (p < 0.005) of the lake's catchment land use, with built-up area increasing by 78.5%, and a reduction in vegetated (37.2%) and water surface (1.8%) areas. A 92.2% reduction in the lakes receiving wetland footprint (p = 0.000003) was noted, with increased nutrient load. The lake's light attenuation was found to be dominated by algae, limited by nitrogen and classified under the oligotrophic class (Trophic State Index < 40), with a threat of eutrophication in an estimated 25 years. Scenario analyses show that the construction of a wetland in the remaining 0.54 hectares of natural wetland will reduce total phosphorus by 35% and total nitrate by 45% (p = 0.05), whereas dredging the lake could reduce them by 80% each (p = 0.0005). Watershed management is the only sustainable solution to control nutrient flow into the lake and enable self-cleansing, factoring in the design of the receiving wetland and groundwater sources.
Field-based methods for measuring greenhouse gases emissions from on-site sanitation systems: A systematic review of published literature
(Heliyon, 2023-04) Prativa, Poudel; Anish, Ghimire; Guy, Howard; Barbara, Evans; Miller, Camargo-Valero A.; Freya, Mills; Olivia, Reddy; Subodh, Sharma; Sarana, Tuladhar; Abraham, Geremew; Kenan, Okurut; Baba, Ngom; Manish, Baidya; Sheila, Dangol
On-site sanitation systems (OSS) are a source of greenhouse gas (GHG) emissions. Although ef- forts have been made recently to measure and quantify emissions from septic tanks using various field-based methods, the vast majority of published literature reporting GHG emissions from OSS units (e.g., pits and tanks) is based on non-empirical evidence. This systematic review presents an overview and limitations of field-based methods used for the quantification of GHG emissions from OSS. Papers published in English were searched in three databases: Google Scholar, PubMed, and Directory of Articles and Journals. Peer-reviewed papers that reported field-based methods applied to containment units in OSS were included in this study. Only eight out of 2085 papers met the inclusion criteria with septic tanks as the sole technology reported and were thus, considered for the review. Most of the studies have been conducted in middle- and high- income countries. Field-based measurements of GHGs are conducted using a flux chamber (FC) and the most commonly used FC methods are (a) the modified simple static FC, (b) automated static FC, and (c) floating FC. Data reported in published studies do not provide sufficient in- formation on the calibration and validation of the results from the FCs used. The complex FC designs, laborious fieldwork operations, and reliance on expensive, specialist equipment, suggest that such methods may not be suitable in Low and Middle-Income countries (LMICs), where re- sources and access to laboratory facilities are limited. Also, the complexity of pits and tank ty- pology in LMICs (i.e., unstandardised designs and sizes) may be a challenge to the use of FCs with fixed dimensions and set operational conditions. The variation in the quantification methods and resulting emission rates among the studies indicates that gaps prevail in the use of existing methods. Therefore, there is still a need for a simple field-based, easily adaptable FC method with adequate calibration and validation that can help in reliably quantifying the emissions from different OSS in any LMICs.
The potential for citizen science to improve the reach of sanitary inspections
(MDPI- Resources, 2020-10) Jo, Herschan; Richard, King; Theresa, Mkandawire; Kenan, Okurut; Dan, J. Lapworth; Rosalind, Malcolm; Katherine, Pond
To achieve Sustainable Development Goals (SDGs) 6, universal and equitable access to safe and affordable drinking-water quality and sanitation for all, and 10, to reduce inequality within and among countries, additional and urgent work is required. Efforts to achieve these Goals in the context of small drinking-water supplies, which are the furthest behind in regards to progress, are of particular need. Reasons for this disparity in progress include the remoteness of access to small drinking-water supplies and the lack of technical and financial capacity for monitoring supplies. The World Health Organization promote the use of Sanitary inspection (SI) as an on-site assessment of risk. Despite the potential to increase the body of knowledge and information on supplies in a region, there has been limited research into the role of citizen science and SIs. To meet SDG targets, we need to improve the reach of SIs. This study uses a mixed methods approach of quantitative on-site SI data collection and remote SI data collection via photographic images, together with qualitative data collection, collected by non-expert students, who are citizens of Malawi, as well as a panel of experts in the field of SI. Results indicate that, although further research into the topic is required prior to widescale implementation, the potential exists for citizens to conduct SI, with remote expert verification of the results using photographic images of supplies. Further documentation or guidance is required to support citizens in this process. The results highlight a critical gap in the availability of appropriate documentation for unprotected spring sources which is urgently required. The use of citizen science for SI data collection is in its infancy. However, this study indicates that there is potential to explore the use of citizen science in this area, which will contribute to achieving SDGs 6 and 10.
Progress of using risk assessment to manage small drinking-water supplies in Rwanda: a preliminary study
(MDPI- Processes, 2023-03) Jo, Herschan; Aime, Tsinda; Kenan, Okurut; Rosalind, Malcolm; Daniel, J. Lapworth; Katherine, Pond
The World Health Organization promotes risk assessment and risk management through Water Safety Plans (WSPs) as the most effective way to manage drinking-water supplies. Despite proven advantages of this approach in other regions, WSPs are still not widely used across small drinking-water supplies in Sub Saharan Africa. The aim of this research is to identify good practices and related gaps which may assist with formal uptake of WSPs for small drinking-water supplies in Rwanda. Through semi-structured interviews with the key stakeholders involved in small drinking-water supply management across Rwanda, the aim is achieved through the investigation of the following: (i) current drinking-water management challenges; (ii) stakeholder collaboration and data management activities including reporting of information; and (iii) the regulatory and policy environment. The use and awareness of WSPs in Rwanda was confirmed as low. However certain drinking-water management activities which align with the WSP methodology are being carried out. These include catchment management and stakeholder collaboration. Although legislation and policy are in place in Rwanda, communication and training of methods to implement WSPs are required to sustainably embed WSPs into practice. Several elements, including community engagement, systematic review of risks and data management, require greater focus to align with the WSP methodology. Respondents highlighted key drinking-water management challenges, including reactive budgeting and lack of sector prioritization, which could benefit from formal WSP implementation.
The relationship between water pressure variations and drinking-water quality in small water supplies: A case of Mukono District, Uganda
(Environmental Challenges, 2023-09) Kenan, Okurut; Jamiru, Ntumwa; Anne, Nakagiri; Jo, Herschan; Aime, Tsinda; Rosalind, Malcolm; Dan, J Lapworth; Kathy, Pond
The supply of a safe and adequate quantity of water is essential for human health and socioeconomic devel- opment. Physiochemical and microbiological quality of water supplied in piped distribution systems can be affected by long water residence times and travel distances. This may be due to low pressure, reservoir storage and insufficient disinfection in the system among other causes. As such, large schemes usually have mechanisms of improving the quality of water along supply and/or distribution networks at reservoir and other points. In contrast, small, piped water supply schemes rarely have the infrastructure and resources to monitor and provide treatment to the water in distribution. The objective of this study was to assess the variation of water quality and water pressure along the supply network in small, piped water systems. The study used mixed methods of quantitative water quality and pressure assessments, alongside stakeholder interviews, to investigate the vari- ability of water pressure and specific water quality parameters across the distribution network, and reliability of supply in two different small water supply schemes in the study area of Mukono, Uganda. Results showed water pressure in small, piped water supply networks have minimal influence on variation of selected water quality parameters in smaller (< 4000 m travel distances) and well operated and maintained systems. A pressure drop from 82.2 m to 22.5 m changed Turbidity by < 1, Apparent Color by < x10 and Total Dissolved Solids by < x102. Proper management of supply systems to ensure optimal residual and continuous pressure can safeguard the quality of water in the distribution systems of small piped water networks against intrusion of contaminants. Good management practice that utilizes historical operational data with continuous capacity development and training support on water quality and pressure fluctuations can significantly improve system performance to meet acceptable standards.