An equitable sanitation coverage promotes sustainability, economic prosperity, and public health protection. This study examined factors affecting sanitation coverage and the potential of selected countries across three income levels (Low-Income, Lower-Middle, and Upper-Middle Income Countries) to meet Sustainable Development Goal 6.2 by developing a Sanitation Coverage Index (SCI). Nine developing countries were selected based on the following sets of criteria: income level, population, and geographical region. Twenty years (2000–2020) of sanitation coverage data were extracted from the JMP database and visualized. The SCI was developed using the service level criteria and examined the local drivers of poor sanitation coverage. Findings show that all countries studied made good progress and have commendable current status, except Ethiopia, Rwanda, and Nigeria. Nigeria has the highest open defecation coverage and may not meet the 2030 target. The SCI result shows that Turkey, Ukraine, and China have excellent coverage (scoring: 44, 43, and 40). Brazil, Bangladesh, and DPR Korea have satisfactory performances (36, 31, and 31), while Nigeria, Rwanda, and Ethiopia recorded unsatisfactory progress (28, 27, and 16). The strongest factors influencing poor coverage include population, high socioeconomic inequalities, and socio-political challenges. Therefore, the institutionalization of minimum acceptable standards, adequate sensitization, and funding could improve sanitation coverage in the countries assessed.

This study focused on designing a drinking water systems sustainability index for Integrated Water Resources Management in low-income countries. Water Supply Systems Sustainability Index (WSSI), a field assessment tool, was designed for rapid appraisal of drinking water systems in selected urban, peri-urban and rural Nigerian communities. The systems were classified into Highly Sustainable, Sustainable, Averagely Sustainable, and Unsustainable WSSI categories. Sanitary Risk Score (SRS) was assigned, classifying drinking water systems into Very High, High, Intermediate (Medium) and Low-Risk categories. WSSI results revealed that for urban systems, 90 are Highly Sustainable, 27 are Sustainable and 12 are Averagely Sustainable. For peri-urban systems, 13 are Highly Sustainable, 7 Sustainable and 1 Averagely Sustainable. Only urban hand-dug wells are in the Very High-Risk category. Public water supplies occurred only in the Low-Risk (17) and Intermediate-Risk (6) categories. Urban and rural boreholes had better quality than peri-urban boreholes. WSSI and SRS correlation result indicated strong positive correlation for urban hand-dug wells' (R² = 0.5688, at p < 0.05) and weak positive correlation between peri-urban hand-dug wells' (R² = 0.1847, at p < 0.05) and urban boreholes' WSSI and SRS (R² = 0.2032, at p < 0.05). Findings showed that drinking water systems are, generally, sustainable and WSSI could be incorporated into community-level water supply assessment.

This study focused on designing a WASH Index for assessing the status of WASH in Primary Healthcare Facilities (PHCs) especially for low- and middle-income countries. To assess the effectiveness of the WASH Index in evaluating the WASH in PHCs, PHCs were selected from 70 Local Government Areas (LGA) across 3 Southwestern States in Nigeria. The WASH index comprises of the five Joint Monitoring Programme service ladders as outlined in the World Health Organization Global Baseline Report for monitoring basic WASH services in health care facilities: water, sanitation, hygiene, waste management and environmental cleaning. The 5 service elements (termed as components) assessed were based on 10 indicators and 30 sub-indicators. The results of the WASH Index of the PHCs were compared statistically on LGA and State basis with emphasis on the status of WASH facilities. The study concludes that the result would further provide baseline information on the status of WASH in PHCs in the selected States in the quest to achieve the Sustainable Development Goals (SDGs). This study recommends that the WASH Index could be adopted an assessment tool for evaluating WASH in PHCs in other to ensure communication of results to policy makers and other relevant stakeholders, for effective monitoring healthcare facilities.

Water security, as a Sustainable Development Goal, ensures that sustainable water supply is consistently available to every individual. A water supply systems (WSS) assessment matrix was designed as a tool for assessing WSS in low-income countries; with selected urban, peri-urban and rural Nigerian communities as case studies. Sustainability of the WSS was assessed through established criteria against five sustainability factors. Sanitary surveys were conducted to evaluate the risks associated with the WSS using sanitary inspection forms, through which the sanitary risk scores (SRS) were derived. For sustainability, the WSS were ranked as Very High, High, Medium and Low Sustainability, and for SRS as Very High, High, Intermediate and Low Risk. A Sustainability and Risk Assessment Matrix (SRAM) was designed using sustainability evaluation and risk assessment for the WSS. The WSS in the rural areas are more 'Secure' than those in urban and peri-urban towns, and boreholes are more 'Secure' than hand-dug wells, but none of the public water points are scored 'Secure'. The paper concludes that SRAM provides a cost-effective method of classification and may serve as a pre-water quality and source sustainability assessment tool, especially in low-income countries, as part of the measures to achieve water security.

Low-cost and easily accessible sludge treatment technologies are necessary in low- and middle-income countries. This study aimed to evaluate the use of Moringa oleifera seed powder (MO) as a natural sludge conditioner for supernatant quality improvement prior to thickening as a result of gravity settling. The zone settling rate (ZSR) and sludge volume index (SVI) were used to evaluate the gravity settling capacity. Supernatant clarification was evaluated in terms of the capacity to remove turbidity, apparent colour, Escherichia coli, and organic matter associated with zeta potential evolution. The effects on the values of pH and electrical conductivity were also evaluated. Finally, the effects on the toxicity (chronic and acute) of the supernatant effluent were examined. A significant supernatant quality improvement was observed with the addition of MO. The ZSR (0.16 cm/min) and SVI (53 mL/g) results showed that the sludge had good sedimentability, and the addition of MO maintained these characteristics in a statistical manner. Increasing the MO dosage increased the zeta potential of the supernatant, resulting in an optimal dosage of 1.2 g/L, with a removal of 90% turbidity, 70% apparent colour, 99% E. coli, and 40% organic matter. The pH and electrical conductivity values did not change with increasing MO dosage, which is a competitive advantage of MO addition compared to iron and aluminium salt addition. A reduction in the ability to remove organic matter was observed at higher dosages of the natural coagulant due to the presence of residual MO in the final effluent. The optimal MO dosage of 1.2 g/L did not affect the acute or chronic toxicity of the supernatant. These results emphasized that M. oleifera seed powder can improve the supernatant quality and can potentially be a low-cost and easily accessible conditioner for wastewater sludge thickening.