This study addresses a critical gap in sanitation and public health research by providing the first numerical assessment of flood-induced pit latrine washout volumes. These latrines are a common sanitation solution in low- and middle-income countries, but their potential to serve as sources of faecal contamination during flood events has remained a subject of debate due to a lack of empirical data. Employing a single-phase Computational Fluid Dynamics (CFD) model, this paper assesses the volume of human waste being washed out from latrines under various conditions, including initial supernatant and sludge volumes and latrine structural integrity. Simulation results suggest a phased release of faecal contaminants, with peak discharge occurring during the initial inundation and recessional phases. These distinct pathways warrant further quantification to determine their contribution to the total pollution load. The results also point to specific preventative measures, such as pre-flood emptying and timely structural repairs for latrines, to mitigate the contamination risks in flood-prone areas.

Onsite sanitation coverage has expanded significantly since 2020, driven by global commitments to eliminate open defecation and the need for adaptable solutions in rapidly urbanising small- and medium-sized cities (<1 million inhabitants) in Low- and Middle-Income Countries. Currently, 53% of individuals with access to a toilet depend on onsite sanitation systems. Despite this prevalence, the contribution of greenhouse gas emissions from household-level excreta storage to climate change remains poorly quantified due to limited empirical evidence. We addressed this gap by conducting direct measurements of methane emissions from 146 onsite sanitation containment units locally referred as pit latrines, holding tanks and septic tanks, across Senegal, Ethiopia, Uganda and Nepal. Methane emission rates exhibited strong skewness with a geometric mean of 7.9 g CH₄ capita⁻¹ day⁻¹, indicating that onsite sanitation containment units alone may account for approximately 3.8% of global anthropogenic CH₄ emissions.

Humanure (human excrement recycled for agricultural use) offers a low-cost, simple treatment option for dry sanitation systems, and a promising organic amendment for crop production. However, no long-term studies have evaluated its impacts under different land management approaches. This study presents findings from a three-year field trial (2021-2024) in West Yorkshire, UK, assessing the effects of humanure on cereal crop yield and soil properties under conventional and regenerative farming practices of a former grassland. The experiment used a semi-randomised block design with two management regimes (conventional and regenerative) and three fertilisation treatments (control, synthetic fertiliser, and humanure), each replicated three times. Crop results showed that humanure increased crop yields compared to the control, demonstrating a fertilisation effect, which was more pronounced under regenerative management. However, yields from humanure treatments were lower than those from synthetic fertilisers. Regenerative management produced higher yields than conventional across all fertiliser types. Soil analyses revealed that fertiliser type had limited influence on physical soil properties, but regenerative practices significantly improved water-stable aggregates. Soil organic matter and total carbon were higher under humanure than other fertiliser regimes, and higher under regenerative management across all fertilisers. Humanure elevated phosphorus and potassium levels, but not outside of acceptable limits. Biological indicators, including worm counts, soil respiration, and fungal biomass, were slightly elevated under humanure treatments and consistently higher in regenerative systems. Due to small sample sizes, detailed statistical analysis was not appropriate, and instead trends are observed and discussed. Overall, this study suggests that humanure is a promising soil amendment, especially when combined with regenerative land management. More investigation is warranted, with greater replication to enable statistical analysis, in order to further explore of the role humanure in realising a circular economy for sanitation and sustainable agriculture.

Sanitation contributes to greenhouse gas (GHG) emissions, but the lack of empirical data adds high uncertainty to current estimates. The Intergovernmental Panel on Climate Change (IPCC) provides expert advice on standard methodologies for estimating emissions. In the wastewater sector, limited empirical emission factors mean that national inventories often fail to reflect the diversity in onsite sanitation systems linked to design, operation and maintenance of household containment units. For that reason, we measured methane emissions from 27 containment units across five Indonesian cities during both dry and wet seasons (two to four times per season over 12- or 24‑hour periods). Sealed containment units had a median emission rate of 2.22 g CH4 cap-1 day-1, rising to 2.43 g CH4 cap-1 day-1 for lined and 17.27 g CH4 cap-1 day-1 for open (unlined) units. Our findings also show that construction features such as the presence of outlets and aeration affect methane emission rates, along with other site‑specific factors (sludge age, loading rate, etc.). These support the need for expanded empirical datasets in low‑ and middle‑income countries where sanitation technologies are predominant and highly heterogeneous. This is essential for improving the accuracy and representativeness of national GHG inventories for the sanitation sector.

AbstractComposting human feces (“humanure”) is a simple, affordable method for recycling waste, producing a material similar to commercial potting mixes. This novel approach contrasts with more common practices like biosolids application and wastewater irrigation, offering new opportunities for fecal reuse in horticulture and home gardening. This study evaluated the suitability of humanure as a potting mix for lettuce (Lactuca sativa) seedlings in an emergence experiment. Four humanure blends from small‐scale composting systems were compared to two garden soils and a commercial potting mix as a control. Emergence speed and total emergence were combined into an emergence index (EI), and seedling size was measured after 25 days. Three of the four humanure blends performed comparably to the control, with EIs over 77.4 and leaf growth above 2.36 cm. The fourth blend, with a lower pH, had good emergence (EI = 53.4) but stunted growth (<0.84 cm). These results highlight the variability in homemade compost quality and the importance of proper management. Garden soils performed poorly in terms of emergence (EI = 12.2 and 7.6), with insufficient seedlings for statistical analysis on growth. This study demonstrates that small‐scale composting of human feces can produce high‐quality compost suitable for use as a potting mix. It also underscores the need for improved guidelines and regulations for the production and use of humanure beyond traditional sewage applications.

In Indonesia and many urban areas, the coexistence of on-site sanitation and groundwater supply poses faecal contamination risks. Indonesian standards recommend a minimum 10-m horizontal separation and 2-m groundwater depth for siting sanitation systems. This study evaluated the effectiveness of these criteria in Metro City by mapping wells and sanitation systems, controlling for other risk factors, and repeat measurements of groundwater depth and well contamination. E. coli was detected in 70% of wells, with a median concentration of positive samples of 47 MPN/100 mL (interquartile range 6 -727 MPN/100 mL). Although 60% of wells were within 10-m of a sanitation system, horizontal separation was not significantly associated with contamination. Shallower groundwater was significantly associated with an increased presence and high concentrations of E. coli. The 2-m threshold was associated with high contamination but not E. coli presence. Water quality and groundwater depth varied over the 2-month dry season sampling period, and associations with risk factors varied between repeat and single sample analyses. Other factors also contributed to contamination, including uncovered wells, presence of livestock and rainfall. The findings highlight the limitations of standardised siting criteria, suggesting that site-specific risk assessments may be more effective in managing water and sanitation risks.

Introduction Unsafe water, sanitation and hygiene (WASH) causes millions of deaths and disability-adjusted life-years annually. Despite global progress towards universal WASH, much of WASH programming continues to fail to improve health outcomes or be sustainable in the longer term, consistently falling short of internal performance indicators and sometimes negatively impacting the well-being of local stakeholders. Although sector experts in high-income countries have often provided explanations for such failures, the opinions of those implementing WASH programming at the ground level are rarely published.Methods In 2020, we purposively recruited 108 front-line WASH professionals in Malawi, South Africa, Tanzania and Zimbabwe to participate in 96 in-depth interviews, explaining why they believe WASH failure persists. Through participatory analysis, including framework analysis with additional axial coding and member-checking of our findings, we determined the core reasons for WASH failure as perceived by participants.Results Interviewees reported poor engagement and commitment of intended users, unrealistic and idealistic expectations held by funders and implementers, and a general lack of workforce and financial capacity as significant contributors to WASH failure. Our analysis shows that these issues stem from WASH programming being implemented as time and budget-constrained projects. This projectisation has led to reduced accountability of funders and implementers to intended users and a focus on measuring inputs and outputs rather than outcomes and impacts. It has also placed high expectations on intended users to sustain WASH services and behaviour change after projects officially end.Conclusions Our findings imply that WASH programming needs to move away from projectisation towards long-term investments with associated accountability to local governments and longitudinal measurements of WASH access, as well as realistic considerations of the needs, abilities and priorities of intended users. Funders need to reconsider the status quo and how adjusting their systems could support sustainable WASH services.

This article examines the challenges faced by transgender and gender non-confirming individuals when attempting to access sanitation in urban India. It highlights how the experiences of these individuals intersect with broader social dynamics related to appearance, which can affect people of all genders. Using an iterative and inductive approach, the study combines insights from interviews with activists, academics and government practitioners, along with focus group discussions involving transgender and gender-nonconforming cisgender participants, to explore gaps in policy and implementation. The research highlights how ‘gendered’ sanitation programming and policy largely neglects non-cisgender communities, focusing predominantly on cisgender women, and often fails to address the nuanced sanitation needs of Transgender and Gender non-conforming persons, particularly transgender women. While sanitation programming emphasises technical infrastructure, social dimensions of sanitation, particularly appearance-based discrimination, remain largely unaddressed, creating exclusionary environments. Drawing on Goffman's theory of stigma, Meyer's Minority Stress Theory, and Bourdieu's concept of symbolic capital, the research elucidates how social stigma, chronic stress from discrimination, and the policing of gendered appearances converge to limit access and safety in sanitation spaces. These intersecting barriers affect both transgender and cisgender individuals who do not conform to normative gender expressions. The research urges a more intersectional, gender-sensitive approach to sanitation that confronts both technical and deeply embedded social obstacles. This research contributes to the limited literature on transgender access to basic services in India and underscores the necessity of addressing appearance-based discrimination to foster truly inclusive sanitation environments.

Households without access to a functioning and well-managed sanitation system produce untreated faecal waste. While connecting households to sewers is ideal in densely populated low-income areas, the connection rates often remain low. Most interventions to increase connectivity focused on addressing financial, social, and legal barriers; there is limited evidence on the effectiveness of behaviour change interventions in promoting sewer connections. Thus, we aim to understand the effectiveness of behaviour change interventions in increasing the uptake of sewer connections. We developed a review protocol with key search terms relating to households, sewers, behaviour change interventions, promotion, and effectiveness. We aimed to identify both the types of interventions deployed and their impact on increasing household sewer connections. Eleven articles met the eligibility criteria and were included in the review. Findings indicate that changes in rates of connection were associated with interventions that included a blend of indirect financial subsidy in the form of a free connection and community-engagement activities. There was limited evidence that behaviour change campaigns without financial incentives lead to changes in sewer connection rates. A multi-component package involving financial subsidies with community engagement is likely to improve the sewer connection rate.

Strengthening local government capacity to improve sanitation and other basic services is a challenge in many low resource countries. There is growing interest in peer learning as a mechanism to spread successful practices and increase local government performance in the settings. However, few studies have investigated if peer learning leads to changes in practices and improved results. The study aims to identify and evaluate the causal linkages between peer learning activities and any changes to participants capacity, local government practices and increases in sanitation coverage in rural districts. Contribution Analysis, a theory-based evaluation approach, was used to design a longitudinal study investigating outputs, outcomes and impacts of two peer learning workshops between Open Defecation Free (ODF) Districts and non-ODF Districts in Mozambique alongside the enablers and barriers to change. The research draws on a survey of 66 participants directly after the workshops and 29 semi-structured follow-up interviews nine months later. We found that despite broader structural challenges that hinder progress in sanitation service provision, the workshops enabled the spread of knowledge of good practices (outputs) some of which were replicated (outcomes). There is evidence that these replicated practices accelerated progress towards ODF status (impact) in some districts. We demonstrate that under the right conditions peer learning can nurture local learning, improve knowledge, spread frugal practices and lead to incremental improvements in local government performance. We therefore recommend it be integrated into broader programmes to maximise benefits.

Access to safe sanitation remains a challenge in urban areas globally, particularly in low- and middle-income countries. In cities like Dhaka, Bangladesh, despite efforts to expand sewer connections, uptake among households remains low. This study investigates both the psychological and administrative barriers to household sewer connections. We conducted a mixed-methods cross-sectional study in five Dhaka zones operated by the Dhaka Water and Sewerage Authority (DWASA). We surveyed 384 households, conducted five Key Informant Interviews, and 10 In-Depth Interviews. Survey participants included households with toilets connected to the foul-water sewer or to open drainage. We used the risks, attitudes, norms, abilities, and self-regulation (RANAS) framework to examine socio-demographics, and psychological factors determining connection behaviour. Individual-level barriers included the lack of knowledge about connection procedures and perceived low risks of disease transmission among those who had not connected to the sewer. Organisational-level barriers included complex administrative processes, high installation costs, bureaucratic delays, inadequate support from DWASA, and outdated infrastructure. Addressing the global urban sanitation crisis requires interventions that simultaneously tackle administrative barriers (such as streamlining processes and enhancing financial support) and psychological factors (including raising awareness about the benefits and procedures of sewer connection and fostering a sense of ownership).

This paper explores the disconnect between policy rhetoric and implementation at the intersection of sanitation equity and climate change in Nairobi, Kenya. To examine the current sanitation adaptation trajectory, we reviewed Nairobi's sanitation policies, planning, and investment frameworks, focusing on their integration with climate adaptation strategies and consideration of equity in terms of distribution, recognition and processes. We used a socio-technical regime framework to map the current sanitation service configurations in Nairobi and projected their future under different climate change scenarios. Our findings provide evidence for a disconnection between policy rhetoric and implementation, prioritising sewerage development at the expense of other sanitation regimes. Despite recognising equity issues in policy, substantive action towards equitable sanitation governance is lacking. This imbalance hinders the realisation of the constitutionally recognised right to adequate sanitation in the foreseeable future. The anticipated impact of climate change on Nairobi's sanitation sector suggests an exacerbation of existing service inequalities. Our projection indicates that by 2030, a sizeable portion of Nairobi's residents will experience poor sanitation services. Our study emphasizes the critical need for a fundamental paradigm shift. It calls for a robust and honest discussion on delivering high-quality, resilient sanitation services at scale including both sewer and non-sewered sanitation and necessitating substantial public investment and support for all systems. This reappraisal is imperative for ensuring equitable and sustainable sanitation solutions in the face of climate change.

Despite sustained efforts over several decades, no region is projected to achieve universal sanitation access by 2030, according to international monitoring frameworks. Climate change is increasingly disrupting human and ecological systems, in turn deepening existing inequalities in access to essential services, including sanitation. Coupled with broader socio-economic and political dynamics, these pressures are expected to further widen the global sanitation service gap. Strengthening the resilience of sanitation systems to climate-related impacts represents a critical component of addressing this challenge. Building resilience requires an understanding of the attributes of sanitation systems and the adaptation actions across scales that contribute to their capacity to anticipate, withstand and recover from climate hazards. While existing scholarship has primarily examined the impacts of climate hazards on sanitation system performance, less attention has been given to resilience-building processes and practices. This systematic review is the first to synthesise the evidence on resilience in sanitation systems. It identifies twenty-seven (n=27) attributes and adaptation actions with potential to enhance resilience. However, with only seventeen (n=17) studies meeting the inclusion criteria and limited empirical evidence, substantial knowledge gaps remain. These findings underscore the urgent need for targeted research and the development of measurable indicators of climate resilience to inform international monitoring frameworks and guide effective adaptation strategies.

In Dhaka, Bangladesh, sewer misconnections persist despite sewer infrastructure expansion by the Dhaka Water Supply and Sewerage Authority (DWASA). This mixed-method cross-sectional study aimed to develop targeted, evidence-based interventions to increase sewer connections in urban communities. We surveyed 384 households and conducted 10 in-depth interviews and two focus group discussions across five DWASA zones. Using the Risks, Attitudes, Norms, Abilities, and Self-regulation (RANAS) framework, we identified key psychological factors influencing sewer connection behaviours. Building on these insights, we mapped psychological factors to Behaviour Change Techniques (BCTs) to develop tailored interventions. Households those were not-connected to sewer exhibited significantly lower awareness of sanitation-related health risks, less confidence in navigating connection procedures, and weaker perceptions of the social benefits of sewer linkage. Qualitative findings revealed widespread dissatisfaction with dysfunctional drainage systems, high connection costs, inadequate maintenance support from DWASA, and bureaucratic delays as significant barriers. These results highlight a complex interplay of psychological, financial, and administrative challenges limiting sewer uptake. Based on these insights, we propose a comprehensive intervention package integrating health education to improve risk awareness, community role models to shift social norms, practical technical guidance to simplify connection processes, and income-adjusted financial incentives to ease economic burdens. The study emphasises the urgent need for integrated, multi-sectoral strategies that address behavioural, structural, and economic barriers simultaneously. Implementing these interventions reduces sewer misconnections, an often-overlooked source of environmental contamination and public health risk, and would advance equitable and sustainable sanitation in rapidly urbanising cities like Dhaka.

On-site sanitation systems (OSS) generate greenhouse gases (GHGs) during the decomposition of fecal matter. The reported measurements of these emissions are confined to a restricted number of research examining septic tanks in high-income nations. We conducted field measurements of onsite containments to generate emissions data for Nepal. This represents the first empirical investigation of greenhouse gas emissions from onsite containments in low- and middle-income countries. Emissions were recorded from a panel of pit latrines (n=18), holding tanks (n=6), septic tanks (n=3), between December 2021 and December 2022. A calibrated static flux chamber was designed was and deployed to collect gases samples at each containment site. Portable gas analyzers were employed to quantify methane (CH4), carbon dioxide (CO2), and nitrous oxide (N2O). Results will be provided in detail. Preliminary investigation showed a substantial range in emissions rates notably CH4 across different types of onsite sanitation containments. Statistical test indicated methane emission rates varied considerably within containment types (P value

Sanitation approaches in low-income urban areas are predominately on-site sanitation, with septic tanks promoted as an improved sanitation solution. While a septic tank system is designed to contain sludge in the tank and discharge effluent to a soil infiltration system, in many urban contexts effluent from tanks discharge directly to open drains or surface waters. This research addresses the paucity of data on pathogen removal and discharge from septic tanks as operated in low-income contexts and the significance of this public health hazard. This study assessed the performance and risks of "septic tanks" discharging to open drains in a low-income neighbourhood in Dhaka, Bangladesh, considering the influence of usage and tank operation on concentrations of Norovirus GII, Salmonella Typhi, Vibrio cholerae, Giardia, Shigella and E. coli in the effluent and receiving drains. While 66% of septic tanks were functioning within design limits, multiple pathogens were detected in all effluent samples, with a mean concentration of 7.6 log10 MPN/100mL for E. coli and 4.2-5.6 log10 genome copies/100mL for pathogens, excluding S. Typhi which was not detected. Children's exposure to septic tank discharge in drains could result in an 18% risk of illness from Norovirus GII and 3% from Giardia annually. The pathogen reduction between the estimated septic tank inflows and measured effluent concentration ranged from 1.3 log10 MPN reduction for E. coli to 2.2 log10 genome copies reduction for Giardia. Increased coverage of septic tanks was significantly associated with reduced concentrations of Shigella in open drains compared to direct discharge from toilets, with increased reduction for septic tanks operating within design standards. Implementing septic tanks without sub-surface infiltration or treatment of effluent is a major concern. The potential health risk of exposure to septic tank effluent warrants increased attention to appropriate technical design, effluent management and alternatives such as networked sanitation.