When pits fill up: Supply and demand for safe pit-emptying services in Kisumu, Kenya

Shared sanitation in informal settlements: A systematic review and meta-analysis of prevalence, preferences, and quality

Shared sanitation facilities are not considered a type of basic sanitation by the WHO/UNICEF Joint Monitoring Programme (JMP), though they may be the only alternative to open defecation in urban informal settlements. Additionally, JMP indicators for sanitation do not cover aspects related to the quality of shared sanitation, such as those outlined in the Human Right to Water and Sanitation (HRTWS) framework. Data on the prevalence of shared sanitation within informal settlement areas is limited, and there is a need to understand user preferences, experiences, and barriers to the use of shared sanitation to inform effective policy and practice. This systematic review aims to summarize the prevalence and number of households sharing sanitation in informal settlements globally, as well as user experiences and barriers to successful implementation of shared sanitation. We included studies available in English and published after January 1, 2000. We retrieved 4741 articles from seven databases and included a total of 167 relevant publications. Among included studies, 54 reported the prevalence of shared sanitation in informal settlements, and 138 studies reported on user perceptions and experiences related to shared sanitation quality. A meta-analysis of studies reporting the prevalence of shared sanitation in informal settlements globally revealed an estimated overall prevalence of 67% [95% CI: 61%-73%]. Commonly reported user preferences included cleanliness to promote continued use of shared facilities, privacy with a lockable door, facilities for menstrual hygiene management, safety and protection against violence, 24/7 access, proper lighting, and shared responsibility for facility management - which align with the HRTWS framework and represent barriers to shared sanitation use. Based on the findings of this review, we recommend including the number of households or people sharing a sanitation facility in monitoring of shared sanitation quality, locating sanitation facilities within compounds, where applicable, and promoting safety, dignity, and privacy of all users in the development of shared sanitation quality indicators.

Assessment of sanitation infrastructure resilience to extreme rainfall and flooding: Evidence from an informal settlement in Kenya

Sanitation infrastructure can fail during heavy rainfall and flooding, allowing the release of fecal waste - and the pathogens it carries - into spaces where people live, work, and play. However, there is a scarcity of reliable frameworks that can effectively assess the resilience of such infrastructure to extreme rainfall and flooding events. The purpose of this study was to develop and apply a novel framework for assessing and ranking the resilience of sanitation infrastructure in informal settlements. A framework for assessing sanitation infrastructure resilience was developed consisting of 19 indicators that were categorized into three domains: physical infrastructure design (8 indicators), operations and management (5 indicators), and environmental factors (6 indicators). The framework was applied to data from 200 shared sanitation facilities in Kibera, Kenya, collected through transect walks, field observations, surveys, and sanitary risk inspections. Results indicate that sanitation infrastructure type impacts resilience. Toilet facilities connected to a piped sewer (r = 1.345, 95% CI: 1.19-1.50) and toilets connected to a septic system (r = 1.014, 95% CI: 0.78-1.25) demonstrated higher levels of resilience compared to latrines (r = 0.663, 95% CI: 0.36-0.97) and hanging toilets (r = 0.014, 95% CI: 0.30-0.33) on a scale ranging from 0 to 4. The key determinants of sanitation infrastructure resilience were physical design, functionality, operational and maintenance routines, and environmental factors. This evidence provides valuable insights for developing standards and guidelines for the design and safe siting of new sanitation infrastructure and encourages investment in sewer and septic systems as superior options for resilient sanitation infrastructure. Additionally, our findings underscore the importance for implementers and communities to prioritize repairing damaged infrastructure, sealing potential discharge points into open drains, and emptying filled containment systems before the onset of the rainy season.

Determinants of Willingness to Pay for Fecal Sludge Management Services and Knowledge Gaps: A Scoping Review

Achieving universal access to safely managed sanitation services is one of the Sustainable Development Goal 6 targets (SDG6.2). The cost and availability of services to ensure the safe management of on-site sanitation, such as pit latrines and septic tanks, can be major barriers for poor households. Particularly, fecal sludge emptying services have become increasingly important due to the growing urban population. This review aims to scope the literature on stated and revealed willingness to pay (WTP) for emptying on-site sanitation systems and to identify determinants of WTP and gaps in knowledge. We performed electronic searches of six databases. After deduplication, 1846 records were identified, of which 14 were included in the review. In these studies, we identified 26 distinct scenarios that reported mean or median WTP values for emptying services and their market price (i.e., price at which the services were provided). Among the 26 scenarios, 77% (n = 20) reported that WTP was lower than the market price. We identified 20 statistically significant determinants of WTP, which can be leveraged when developing or improving manual and mechanical emptying services to attract more customers. Future research should consider services that adopt flexible pricing or mobile money payment and optimize their emptying operations to increase WTP. Validating the effectiveness of such services in solving the WTP-market price imbalance is a significant knowledge gap.

The role of emptying services in provision of safely managed sanitation: A classification and quantification of the needs of LMICs

Classifications for onsite sanitation in terms of facility type (septic tanks, pit latrines) exist, but connecting these facilities to the wider sanitation value chain via improved containment, emptying, and collection has not been well explored. Using existing Joint Monitoring Programme facility classifications and secondary data on piped water access, a Service Typology was developed to classify and quantify the primary emptying service needs of household level onsite sanitation facilities. Facilities in six Sustainable Development Goal (SDG) regions were classified as Emptiable (faecal sludge can be removed either via Mechanized or Non-Mechanized means) or Unemptiable. Of the 722 million household level sanitation facilities assessed in these regions, 32% were found to be emptiable via Mechanized means, 50% via Non-Mechanized means and 18% were found to be Unemptiable pits. The volume (by number of facilities) and density (as a proportion of the full population) of each service type were estimated by SDG region and by country. Results from this study provide background data on the role of emptying sanitation facilities in achieving SDG6, and can be incorporated into investment priorities, policy framing, technology development, infrastructure development, and targeted behaviour change strategies.

Patterns and Drivers of Household Sanitation Access and Sustainability in Kwale County, Kenya

Many sanitation interventions suffer from poor sustainability. Failure to maintain or replace toilet facilities risks exposing communities to environmental pathogens, yet little is known about the factors that drive sustained access beyond project life spans. Using data from a cohort of 1666 households in Kwale County, Kenya, we investigated the factors associated with changes in sanitation access between 2015 and 2017. Sanitation access is defined as access to an improved or unimproved facility within the household compound that is functional and in use. A range of contextual, psychosocial, and technological covariates were included in logistic regression models to estimate their associations with (1) the odds of sustaining sanitation access and (2) the odds of gaining sanitation access. Over two years, 28.3% households sustained sanitation access, 4.7% lost access, 17.7% gained access, and 49.2% remained without access. Factors associated with increased odds of households sustaining sanitation access included not sharing the facility and presence of a solid washable slab. Factors associated with increased odds of households gaining sanitation access included a head with at least secondary school education, level of coarse soil fragments, and higher local sanitation coverage. Results from this study can be used by sanitation programs to improve the rates of initial and sustained adoption of sanitation.

Will Households Invest in Safe Sanitation? Results from an Experimental Demand Trial in Nakuru, Kenya

Unsafe sanitation is an increasing public health concern for rapidly expanding cities in low-income countries. Understanding household demand for improved sanitation infrastructure is critical for planning effective sanitation investments. In this study, we compared the stated and revealed willingness to pay (WTP) for high-quality, pour-flush latrines among households in low-income areas in the city of Nakuru, Kenya. We found that stated WTP for high-quality, pour-flush latrines was much lower than market prices: less than 5% of households were willing to pay the full costs, which we estimated between 87,100–82,900 Kenyan Shillings (KES), or 871–829 USD. In addition, we found large discrepancies between stated and revealed WTP. For example, 90% of households stated that they would be willing to pay a discounted amount of 10,000 KES (100 USD) for a high-quality, pour-flush latrine, but only 10% of households redeemed vouchers at this price point (paid via six installment payments). Households reported that financial constraints (i.e., lack of cash, other spending priorities) were the main barriers to voucher redemption, even at highly discounted prices. Our results emphasize the importance of financial interventions that address the sizable gaps between the costs of sanitation products and customer demand among low-income populations.

How Much Will Safe Sanitation for all Cost? Evidence from Five Cities

Global sustainable development goals call for universal access to safely managed sanitation by 2030. Here, we demonstrate methods to estimate the financial requirements for meeting this commitment in urban settings of low-income countries. Our methods considered two financial requirements: (i) the subsidies needed to bridge the gap between the willingness-to-pay of low-income households and actual market prices of toilets and emptying services and (ii) the amounts needed to expand the municipal waste management infrastructure for unserved populations. We applied our methods in five cities- Kisumu, Malindi, Nakuru in Kenya; Kumasi in Ghana; and Rangpur in Bangladesh and compared three to five sanitation approaches in each city. We collected detailed cost data on the sanitation infrastructure, products, and services from 76 key informants across the five cities, and we surveyed a total of 2381 low-income households to estimate willingness-to-pay. We found that the total financial requirements for achieving universal sanitation in the next 10 years and their breakdown between household subsidies and municipal infrastructure varied greatly between sanitation approaches. Across our study cities, sewerage was the costliest approach (total financial requirements of 16-24 USD/person/year), followed by container-based sanitation (10-17 USD/person/year), onsite sanitation (2-14 USD/person/year), and mini-sewers connecting several toilets to communal septic tanks (3-5 USD/person/year). Further applications of our methods can guide sanitation planning in other cities.