A Systematic Review of Households’ Fecal Sludge Management Situation to Identify Gaps and Improve Services: A Case of Kigali City, Rwanda

Abstract

Background: Kigali, Rwanda’s rapidly growing capital, faces major challenges in household-level Fecal Sludge Management (FSM), with over 89% of households using pit latrines and only 48% accessing unshared sanitation. FSM services are limited, costly, and poorly executed, leading to frequent illegal dumping. Objective: This review analyzes the literature on sanitation in Kigali to identify key gaps, synergies, and recommendations for improvement. Methods: Following PRISMA 2020 guidelines, 73 relevant publications were selected from various scientific and governmental sources. Publications were included only if they were published from 2013 to 2024 and had information on sanitation in Kigali. NOS and JBI tools were utilized to assess the quality of included publications. Results: Data were categorized into four themes, (1) access to sanitation, (2) FSM services, (3) public health, and (4) sanitation governance, and analyzed using thematic, narrative, and descriptive methods. Findings reveal a dysfunctional FSM service chain, weak policy enforcement due to overlapping responsibilities, underfunding, and limited private sector participation. These issues contribute to poor sanitation, inadequate hygiene, and prevalence of diarrheal diseases and Tropical Neglected Diseases, especially among young children. Conclusions: The review recommends strengthening governance and clarifying roles, enforcing adaptable regulations, promoting public–private partnerships, and managing the full FSM service chain more effectively. Future research should focus on developing context-specific technologies and financing strategies to support sustainable FSM solutions in Kigali.

1. Introduction

According to SDG 6, the global population should have 100% access to Safely Managed Sanitation services by 2030, defined as the use of an improved facility not shared by other households and where excreta are safely disposed of in situ or removed and treated off-site [1]. The Joint Monitoring Group (JMP) reported that as of 2022, only 57% of the world’s population had access to this type of service, compared to 31% in Sub–Saharan Africa [2]. Approximately 2.7 billion people worldwide use Onsite Sanitation Technologies (OSTs) as a means of excreta management, with more than 439 million residing in Africa [2]. The use of OST is generally due to nonexistent or insufficient centralized sewer systems. OSTs are defined as facilities that collect and store excreta for land-based treatment or collection, followed by road-based conveyance to final treatment and end-use; —a service chain that is designated as Fecal Sludge Management (FSM) [3,4]. Simple pit latrines are the most commonly used type of OST by households in most African countries, with an average of 21% and above 80% in some countries [5,6,7].

Recent literature suggests that FSM services that enhance the functionality and operation of OST likely offer more inclusive and sustainable alternatives compared to conventional sewer systems, which are expensive and resource-intensive [1,3,6,8,9]. This is, however, contested as it depends on the scale of the system and whether the systems carry all domestic wastewater, including black, gray, and stormwater, or only a part of it, and other site-specific contexts [10,11]. Previous studies on sanitation in Africa have identified common challenges to improved sanitation, such as financial constraints, inadequate regulation, lack of technical capacity, and high urbanization rates; however, the difference in social settings and governance of each country often offers a unique context, despite some similarities [6,12,13,14,15].

Kigali; the capital of Rwanda; is a densely populated city with a sanitation system that mainly depends on OST with limited FSM services [16,17,18]. The population density is about 2400 inhabitants per km², and the annual growth rate for the past decade was 4.4% [7]. Pit latrines account for about 89% of the sanitation technologies used by households, with only 48% of the city population having access to unshared sanitation facilities [7]. Additionally, several studies and report indicate that the quality of pit latrines in the city is poor, sanitation infrastructure are inadequate and there is limited expertise in the matter [16,18,19,20,21]. As a general practice in Kigali, pit latrines are emptied when they fill up, after which the sludge is transported to a disposal site; generally, the Nduba Landfill [16,21]. However, containing, emptying, transporting, and disposing of the sludge are not always carried out properly, with the rate of professional latrine emptying currently ranging from 6 to 15% [17,22,23]. Instead, illegal emptying and dumping are common, mainly because proper sludge removal rarely is considered in latrine design and construction, is expensive, and is not normalized [16,17,20,22]. While construction of a centralized FS treatment plant is set to begin soon [18,24], low demand for emptying services and limited household sanitation access could impede its operation due to insufficient daily sludge delivery. These sanitary conditions increase the risks of outbreak and spread of poor sanitation-related diseases such as diarrhea, dysentery, typhoid, and respiratory infections, which have several negative health outcomes, including malnutrition among children under five years [1,25].

In addition, these conditions are exacerbated by increasing risks of floods and landslides in Kigali due to climate change and urbanization. While the majority of studies on sanitation in Kigali focus on unplanned settlements, there is limited literature addressing the citywide sanitation context and emanating developmental, environmental, and health risks. To address these issues, this study aims to evaluate FSM at the household level in Kigali to identify gaps and recommendations for improved services. Through a comprehensive literature review, recommendations were developed to assist city planners, service providers, and researchers in making informed decisions for enhanced services. In addition to being the most populated and rapidly growing city in Rwanda, Kigali shares similarities with other low-income and middle-income cities, such as inequitable settlements, absence of sewered and treatment systems, rapid growth, limited access to sanitation services, and climate change. While the focus is on Kigali, the recommendations for improved sanitation services and methodological development are also relevant to other cities in similar conditions in Rwanda and other countries.

2. Methodology

2.1. Literature Search and Screening

To comprehensively synthesize the situation of households’ FSM in Kigali, the literature treating similar subjects was reviewed in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) [26]. A literature search was conducted using Google, Google Scholar, ResearchGate, PubMed, and ScienceDirect. Keywords used in the search were onsite sanitation in Kigali, pit latrines and cesspits in Kigali, households‘ sanitation in Kigali, sanitation policy, and sanitation standards. The reviewed literature consisted of publications on sanitation in Kigali or Rwanda, focusing on the containment of fecal sludge, emptying services, treatment, sanitation access, and governance. The literature comprised scientific and government publications (policies, laws, regulations, standards, guidelines, and reports), including data about sanitation in Kigali and published in 2013–2024. The approach of reviewing both scientific and government publications was chosen to allow a broad understanding of the situation of household FSM in Kigali.

Government publications on Rwanda’s sanitation profile, laws, strategies, policies, standards, reports and guidelines were reviewed from websites of government institutions and international organizations, such as the National Institute of Statistics of Rwanda, Ministries, and the JMP WASH (Water, Sanitation, and Hygiene) data portal. Government publications published before 2013 were included if there were no amendments or updated publications.

A three-step data screening and extraction process was used to extract data from the reviewed publications. The first step consisted of identifying relevant publications based on the search keywords. The second step consisted of screening the titles and abstracts of the identified publications against the inclusion criteria. The third step was to read the included publications to extract and synthesize information related to sanitation in Kigali.

Using the Prisma 2020 screening process, a total of 270 publications were screened by two reviewers based on the set inclusion and exclusion criteria, and 73 were retained for the review (Figure 1). Excluded publications are those not meeting inclusion criteria, while those not retrieved are publications for which the full text could not be located or reached. All included publications are available in Supplementary Materials.

2.2. Information Extraction and Analysis

The information extracted from the retained publications consisted of qualitative and quantitative data. A combination of thematic, descriptive, and narrative methods was used to analyze data [27,28], as illustrated in Figure 2. Information from the included publications was first extracted and categorized into four main themes: (1) access to sanitation, (2) Fecal Sludge Management service, (3) public health, and (4) sanitation governance. The four themes were selected because they were recurring and provided broad coverage of the mentioned features of FSM in the publications. Whereas access to sanitation refers to the access coverage in terms of proportion, type, and quality of facilities used by households, Fecal Sludge Management services refer to the service chain, including containment, emptying service, transport, treatment, and disposal of FS. The theme of public health primarily focuses on diseases and health outcomes related to sanitation in Kigali. Sanitation governance refers to institutional and regulatory frameworks in the sanitation sector, which are key pillars of a well-functioning enabling environment of sanitation [16]. While the institutional framework identifies key institutions and assigns roles to play in advancing sanitation, the regulatory framework paves the way to ensuring compliance and accountability of different stakeholders, including public institutions, the private sector, non-profits, and end users. However, some significant themes were not covered, such as sanitation financing and markets, climate change, fecal sludge treatment technologies, and environmental pollution, due to the scarcity of studies covering these topics meeting the inclusion criteria.

For each of the four selected themes, information was gathered on three key aspects: status, issues, and recommendations. The purpose of these key aspects was to compile all information relevant to understanding current conditions, together with suggested recommendations from the included publications. This included a narrative analysis and triangulation of data to build an in-depth understanding of contextual conditions. For each theme, tables and figures were utilized to present and aggregate summaries of data. Last, potential strengths and recommendations were synthesized from the included publications under the selected themes to develop priority actions and synergies to improve FSM.

2.3. Quality and Bias Assessment

To prevent bias and ensure the relevance of included publications, a bias and quality assessment was performed on the seventy-three (73) included publications. Of these, 40 publications were evaluated using the adapted Newcastle Ottawa Scale [29] and JBI [30] quality assessment tools (see Appendix A, Table A1, for the List of included scientific publications, and Appendix B, Table A2 and Table A3, for evaluation results per publication). Among those, 17 publications were rated as high quality, 19 as good quality, and 1 as satisfactory, primarily due to insufficient description of sampling methods and statistical tests. 3 publications were rated as poor quality, due to poorly described methods of sampling, analysis, and referencing to previous studies. However, these publications were not excluded as their findings aligned with high-quality studies.

33 government publications did not meet the evaluation criteria of the quality assessment tools, and were instead evaluated by verifying their authenticity by checking if they were approved by the responsible authorities and uploaded on the official website.

3. Results

3.1. Access to Sanitation in Kigali

Indicators used in monitoring access to sanitation in Kigali are presented in

Table 1. Sanitation coverage in Kigali City by type of facility, from 2014 to 2022.

	Source	EICV4 * 4 2014 (%)	EICV5 * 5 2017 (%)	RPHC ** 2022 (%)
Facility
Improved flush toilet/WC system	Flush toilet/WC system	8.5	8.5	15
	Pit latrine with constructed floor slab	84.7	85.2	81.7
Unimproved pit latrine without a constructed floor slab	Pit latrine without a constructed floor slab	5.8	3.6	2
	Other or no toilet	1.0	1.9	1.2
Total		100	100	100
Improved facility not shared with other households (Flush toilet or Pit latrine)		42.2	41.7	48

* 4^ème and 5^ème Enquête Intégrale sur les Conditions de Vie des Ménages, [31,32] ** Rwanda Population and Housing Census [7].

and

Table 2. Percentage of households by type of toilets and districts in Kigali city [7].

	District	Nyarugenge	Gasabo	Kicukiro	Total
Feature
Flush toilet or WC system – Not shared (%)		9.1	11	20.5	13.2
Flush toilet or WC system – Shared (%)		1.8	1.6	2.1	1.8
Pit latrine with constructed floor slab – Not shared (%)		30.4	39.8	29	34.8
Pit Latrine with constructed floor slab – Shared (%)		55.5	44	45.5	46.9
Pit latrine without constructed floor slab —Not shared (%)		1.5	1.8	0.7	1.4
Pit latrine without a constructed slab – Shared (%)		0.8	0.6	0.6	0.6
Others/no toilet (%)		1	1.2	1.6	1.2
Total (%)		100	100	100	100
Population		374,319	879,505	491,731	3,002,699

, including information on the type of toilet used by a household and whether it is shared with other households. The number of households sharing one toilet is not monitored, nor is the number of people with access to safely managed sanitation services.

Table 1 shows that, from 2014 to 2016, some achievements were made in sanitation in Kigali. Access to improved facilities not shared with other households increased by 5.8% from 2014 to 2022, while the share of people without toilets has been stable around 1–2%, with slight variations between censuses potentially due to differences in sampling coverage. The figures in Table 1 and Table 2 also suggest a high prevalence of shared toilets in Kigali, of which over 80% are pit latrines. The improvement in sanitation access registered in this period might be related to the implementation of the 7-year NST 1, which aimed at 100% access to basic sanitation, growth of the city in estates, and implementation of the Kigali Masterplan. However, the indicators show that the progress is slow compared to the set goals, which suggests that government inputs, in terms of governance, enforcement, and financing, are low [33,34,35]. The slow progress could also reflect social disparities in access to sanitation; for example, poor quality toilets are prevalent in unplanned settlements of Kigali. Moreover, some initiatives denounce pro-poor sanitation policies [16,17,33].

The indicators show that Kigali has widespread access to toilets; however, most facilities are shared and are reported to be unsanitary and, in most cases, not available when required in dense settlements of Kigali city [15,17]. This happens when the pit latrines are located far from the house, are shared by more than one household, or are full. When pit latrines become full, there is a practice of open defecation on the streets, behind houses, in the stormwater channels, especially during the night and in locations with more toilet sharing in dense settlements [16]. These issues are particularly severe in informal settlements, where high population and housing density, and mindsets leave little space for proper sanitation infrastructure.

Kigali has few Decentralized Wastewater Systems (DWWSs), which in turn mainly serve people living in high-income estates, accounting for less than 7% of Kigali’s population. These decentralized systems have further been reported as dysfunctional, producing substandard quality effluent and discharging into ponds that leak into the environment, mainly due to poor operation and maintenance [36,37,38]. Moreover, this level of service is not monitored; instead, it is merged with people using flush toilets.

Another contributing factor to the lack of access to sanitation is the market, which only offers limited choices meeting the needs and affordability of different household categories. While innovative products like SATO are entering the markets as alternatives to traditional pit latrines and gaining popularity, their adoption remains low [39]. These products are considered effective in mitigating some of the adverse health and esthetic impacts associated with traditional pit latrines, even though they do not solve the issue of containment.

In addition to the need for access to improved facilities, poor hygiene practices–such as dirty toilets and not washing hands after using the toilet–were reported as contributing to contaminated water at the point of use and potentially causing poor sanitation-related diseases and dislike of toilets among users [40].

Additionally, a lack of data on containment hinders the development of effective FSM, especially by limiting business planning and leading to unsafe FS emptying and disposal. Research by Ross and Pinfold revealed that most pit latrines in Kigali are deep and unlined [17]. However, the proportional use of such pit latrines is not monitored, as indicated in Table 2. Concerning flush toilets, it is not clear whether they discharge into cesspits, septic tanks, or DWWSs. However, the 7% from DWWS were reported not to be functioning well [36,37,38]. While safely managed sanitation services are not officially monitored, [18] highlights plans to increase access to sanitation from 2024 to 2029, including construction of fecal and sewage treatment plants in Kigali, as well as sensitizing households to adopt safe and modern sanitation and hygiene practices.

Lastly, a comparison between monitored sanitation indicators by the Rwandan government and the SDG 6 Ladder for sanitation services (

Table 3. A comparison of indicators used for sanitation access in Kigali and the SDG 6 Ladder for sanitation services.

Sanitation Indicators in Rwanda	SDG 6 Ladder for Sanitation Services
No data	Safely managed	Use of an improved facility that is exclusive to a single household, where excreta is either safely handled on-site or transported and treated elsewhere.
Use of a flush toilet/WC system not shared with other households	Basic	Use of an improved facility that is exclusive to a single household
Use of a pit latrine with a constructed floor slab, not shared with other households
Use of a flush toilet/WC system shared with other households	Limited	Use of an improved facility that is shared with other households
Use of a pit latrine with a constructed floor slab, shared with other households
Use of a pit latrine without a constructed floor slab, not shared with other households	Unimproved	Use of a pit latrine without a slab or platform, hanging latrine, or bucket latrine
Use of a pit latrine without a constructed slab, shared with other households	Open Defecation	Defecating in fields, forests, bushes, open bodies of water, beaches, or other open places, or with solid wastes
Others/no toilet

) shows that are limitations to the monitoring of SDG-related features in Rwanda, which can generate misalignment between objectives of the SDGs and related national strategies, including NT1, NST2, and Vision 2050. In addition, as over 50% of households in Kigali share toilets with other households [17,18,21,41], this means that over half of households in Kigali have limited access to sanitation as per the SDG 6 indicators.

Recommendations from the reviewed publications for improved access to sanitation in Kigali are synthesized in

Table 4. Synthesis of recommendations from the reviewed publications to improve sanitation access coverage in Kigali.

Recommendation	Source
Increase awareness of proper fecal disposal by educating communities on sanitation behavior change	[15,18,19,41,42]
Promote a diversified customer-centered supply chain for household sanitation facilities and financing mechanisms	[12,18,41,43]
Increase investment in sanitation infrastructure and promote decentralized sanitation technologies	[21,42,44]
Promote contextualized, low-cost, and easy-to-maintain and empty sanitation technologies, particularly in informal settlements	[15,17]
Enhance urban housing development that facilitates sustainable wastewater management	[21]
Develop sustainable legal instruments for planning, development, monitoring, and management of wastewater treatment systems	[36]
Develop self-enforcing mechanisms for implementation of legal instruments	[17]
Improve governance on the development and implementation of quality sanitation facilities to increase the quality of access coverage	[14,18]

.

3.2. Fecal Sludge Management Service in Kigali

The reviewed publications indicate that Kigali faces challenges of FSM due to the absence of an enabling environment. This results in low-quality, hard-to-maintain facilities, a significant number of underserved areas, especially densely populated settlements, insufficient integration of water, sanitation, and hygiene services, unfavorable working conditions for sanitation workers, expensive services, limited demand, and harmful practices, such as the improper disposal of FS into stormwater systems.

Information gathered from the reviewed publications was used to describe the current FSM service chain in Kigali and develop recommendations. Figure 3 illustrates the FSM service chain in Kigali; compiled from [16,17,19,20,23,45]; and the recommended service chain for safely managed sanitation; compiled from [1,3,46]. In Figure 3, safely managed FS is reached when all the components in gray and green colors are available and properly operated by the different entities in blue, depending on the local regulatory framework.

As defined by the WHO, the FSM service chain can lead to safely managed sanitation if it is well-planned, implemented, and monitored [47]. In Kigali, the FSM service chain has several missing components (Figure 3), such as treatment, safe end-use, and disposal [18,21,36]. In the absence of sewered systems, onsite sanitation systems (about 91%) and DWWS (about 7%) are used. The collection consists of pit latrines and flushing toilets discharging into septic tanks and soak pits. Households are responsible for the construction of collection facilities of their choice, subject to approval from local government authorities and regular monitoring by the Ministry of Health. However, in practice, such monitoring and approval are seldom implemented (Figure 3). The containment, emptying, and transport of FS are also not functioning efficiently [17,22]. While conveyance and transport involve professional desludging of filled containments and safe transport to treatment facilities, in the case of Kigali, practices often diverge from this standard. Common practices include sealing full containment and digging new ones, using illegal desludging and dumping (Figure 3). In addition to being of poor quality, most pit latrines are deep, unlined, and contain solid waste, thus requiring advanced manual emptying techniques, more time for servicing and increased risk of occupational exposure for workers [22,23,48]. Professional emptying services are used for a small fraction of containment, estimated between 2% and 7%. The treatment is currently limited to disposal at Nduba Landfill; a licensed dumping site managed by the utility. The landfill lacks a lined bottom and is subject to leachate, posing a high potential for contaminating neighboring communities and underground water [2,19,49,50]. This lack of a centralized treatment facility can partly explain the low proportion of safely managed fecal sludge. However, construction of a centralized treatment plant is set to begin soon [18], and some private companies have piloted small-scale solutions, such as the transformation of FS into briquettes [51] and a waste-to-resource project at a site for solid and hazardous waste [52].

In Kigali, there are about seven licensed exhauster trucks and many unlicensed manual emptying companies [16,45]. In various areas of Kigali, wastewater is directly discharged into open stormwater drainage channels and rivers [44] suggesting a high prevalence of illegal emptying and low demand for professional emptying. This phenomenon is also believed to be fueled by voluminous pits that take a long time to fill [17,53] and the high cost of services, from USD 61 to USD 96 [22]. The unwillingness of landlords to maintain a pit latrine used by many tenants, and the refusal of tenants to maintain a toilet that does not belong to them [12,54] are also barriers to services. Households that cannot afford professional services prefer to do it themselves or hire informal emptying services [22]. Additionally, factors such as transport of sludge long distances to the disposal site, sharing toilets between several households, and preferring volumetric pricing over a flat fee, play a significant role in creating a huge gap between willingness to pay for professional emptying services and the price, which often make customers opt for unprofessional emptying [55].

In an attempt to understand how emptying costs can be alleviated, a study conducted by [56] found that internal cross-subsidy for shared costs is a viable funding mechanism when serving corporations, high-income households, and households without access to formal roads. However, to make it possible, it requires more mechanical jobs to subsidy semi-mechanical jobs, hence requiring a revision of related regulations [56]. Limited advancement of the sanitation sector can also be attributed to limited sector funding. The water and sanitation sector, being implemented by one department, is given a budget as a sector; however, about 80% of its funds are for water, whereas a small portion is given to sanitation. This discrepancy can be explained by a lack of prioritization and evidence-based budgeting for sanitation [13,35].

To address gaps identified in the FSM service chain in Kigali, recommendations from the reviewed publications are synthesized in

Table 5. Synthesis of recommendations from reviewed publications to improve fecal sludge management service in Kigali.

Recommendation	Source
Review emptying services regulations to make services affordable and facilitate adaptations of emptying techniques, by supporting the development of equitable tariffs, including cross subsidies and flexible payment schemes, and implementation of occupational safety and health protection for sanitation workers	[22,45,48,51,53,55,56,57]
Develop citywide wastewater treatment options and accelerate the construction of planned centralized wastewater treatment facilities	[18,21,49,50,51]
Improve solid waste management services in densely populated settlements, and enhance community awareness	[21,23,44,45,51]
Enhance data collection to support a citywide cross-subsidy framework, through assessments to understand customer demography and barriers and motivations to adopt alternative sanitation solutions,	[13,43,45,53,58]
Improve the operation and management of ponds and other decentralized wastewater systems, with permanent skilled staff and sustainable service payment schemes	[37,38,55]
Promote and facilitate stakeholder engagement, including practitioners and the private sector, to enhance their capacity for a collective effort to improve FSM services	[18,53,58]
Advocate for increased funding for the sanitation sector	[13,21,58]
Establish an enabling environment that facilitates sustainable service and equitable delivery at each stage of the FSM chain	[16,17,20]
Improve the quality of containment and diversify sanitation solutions that are affordable, sustainable, and serviceable	[41,43]
Integrate environmental protection in FSM	[51]

.

3.3. Public Health Related to Sanitation in Kigali

Access to adequate sanitation is among the major prevention and elimination measures of Neglected Tropical Diseases (NTDs), diarrhea, and other diseases related to poor sanitation, and significantly reduces negative health outcomes such as stunting [25,59]. WHO defines these diseases as a diverse group of conditions caused by pathogens and related to environmental conditions [59,60]. The pathogens that primarily pose health issues in Rwanda are bacteria (E. coli, Salmonella, Shigella, Vibrio cholerae, etc.), viruses (Adenoviruses, Hepatitis, Polioviruses, Rotaviruses, etc.), Protozoa (cryptosporidium, Entamoeba histolytica, Giardia intestinalis, Cyclospora cayetanensis), and helminths (Hymenolepis, Schistosoma, Taenia, etc.). These pathogens are transmitted through different routes, including direct contact, vectors, polluted water, and contaminated soil [1,25].

In Rwanda, although other types of NTDs are present, intestinal worms or soil-transmitted helminthiasis (STH) is the most prevalent, with rates of 65.8%, 45.3%, and 41% nationally among school-aged children in 2008, 2014, and 2020; compared to less than 20%, 20%, and 10% in Kigali [61]. In 2010, 2014, and 2019, Kigali recorded 11%, 8%, and 12% of diarrhea among children under five years old against national rates of 13%, 12.1%, and 14%. In the same period, the recorded proportions of stunted children were 23.5%, 22.7%, and 21% in Kigali, while at the national level it was 44.2%, 38%, and 33% [62,63,64]. A review of this data in 2024 showed that there were no clear relationships between Water, Sanitation, and Hygiene (WASH) behaviors and diarrhea trends among children under 5 years old but also emphasized that there has been limited progress in access to WASH services during the same period [65]. Similarly, in a study on diarrhea cases on a group of 794 children in 2021, [66] it was found that there was a significant decrease in diarrhea cases due to vaccination against Rotavirus (from 41% pre-vaccination to 6.5% post-vaccination). However, they found that Shigella and Escherichia coli had replaced rotavirus and diarrhea as causative agents with 11% and 12% proportions, respectively. However, the authors suggested that this decline may also be linked to restricted movement during COVID-19 and improved access to WASH. Nonetheless, they emphasized that a general a trend of increasing variant cases requires more efforts to enhance WASH in addition to vaccination [66].

A review in a related study sought to understand the determinants of childhood stunting in Rwanda and confirmed that factors such as inadequate sanitation and related infections among children heightened the likelihood of stunting, including in Kigali [67]. This is also confirmed by other studies that have linked stunting in children to recurrent diarrheal diseases caused by poor sanitation [68,69,70].

Another study aimed to understand the prevalence of Intestinal Helminthiasis and Schistosomiasis among preschool children in Kigali [71]. The infection rate among tested children was 26.3% and this was associated with using contaminated water or exposure to a potentially polluted environment by pit latrines, such as wet and low temperature soil, which are ideal conditions for helminth survival.

In another study conducted by [72] in a district of Kigali, caregivers acknowledged the role of poor sanitation in intestinal parasite infections (IPIs) among children. Specifically, 57.7% of caregivers identified a lack of knowledge as a challenge to implementing preventive practices against IPIs, while 25.6% recognized inadequate sanitation as another challenge. Additionally, 62.6% of caregivers believed that proper sanitation and waste disposal are important for preventing IPIs. According to a working paper published in 2018 on critical WASH challenges in Rwanda, integrated WASH services were found to enhance sanitation outcomes [34]. Water shortage and inequitable distribution in Kigali have also been found to negatively impact sanitation practices and increase the likelihood of waterborne diseases [73].

The recommendations by the reviewed publications to improve public health related to sanitation in Kigali are synthesized in

Table 6. Synthesis of recommendations from the reviewed publications to improve public health related to sanitation in Kigali.

Recommendation	Source
Increase educational and behavioral change interventions that extend beyond infrastructure availability, especially in areas with poor sanitation and hygiene, to mitigate negative health outcomes	[65,71,72,73]
Improve access to WASH services to mitigate infections from variant pathogens causing diarrhea, and enforce protection of wetlands from human pollutant activities	[66,71]
Develop and promote holistic approaches to WASH services and environmental health that consider the broad impact on households beyond water availability	[34,73]
Invest in improved environmental health and improved policies for factors underlying stunting; including sanitation; to reduce the burden of diarrhea-causing pathogens	[67]
Invest in understanding the inhibitors of sustainable household WASH services and practices, as well as other moderating factors that affect household WASH behavior change and childhood diarrhea	[65]

.

3.4. Sanitation Governance in Rwanda and Kigali

3.4.1. Institutional Framework

In the new National Water and Sanitation Policy of 2023 [74], new institutions were added to the institutional frameworks, such as the Ministry of Environment and the Rwanda Development Board. Slight changes were made from the previous policy regarding the institution’s responsibilities; for example, in the previous policy, households were responsible for capital expenditure, operation, and maintenance of onsite facilities, while in the new policy, they will only be involved in planning, commissioning, and representing consumer interests. In addition, whereas WHO recommends regular sanitary inspections to ensure sanitation safety planning [45], the previous policy proposed inspections but did not assign them to any institution.

Figure 4 presents the assigned responsibilities for the main stakeholders according to the new policy, together with associated policy actions. This shows that, while each institution is assigned a specific responsibility, the responsibility for a particular action is shared among many institutions. For example, the policy action of Prioritizing waterless excreta disposal solutions in households without water connections is assigned to MINALOC, WASAC Group, MININFRA, CoK, Districts, and DPs (Figure 4). The current policy does not include sanitary inspections, which is a critical gap in sanitation safety planning. Some similarities are also identified in the responsibilities assigned to each institution; for example, the Ministry of Infrastructure coordinates the legal and regulatory framework and sector performance monitoring and is also responsible for monitoring and evaluation of sanitation infrastructure, while the Ministry of Finance and Economic Planning is responsible for monitoring and evaluation, and Rwanda Utility Regulatory Agency is accountable for sector regulation.

Planning and decision-making processes are heavily centralized, with responsibilities assigned to multiple agencies, each having a stake in some aspects of service delivery, while the City of Kigali lacks the autonomy to enact [50]. Previous studies have raised concerns about the overlapping and scattered responsibilities, as well as centralized decision-making outlined in the previous policy; issues that persist in the new policy. This carries the risk of causing confusion among stakeholders, reducing accountability, and hindering effective coordination during policy implementation [13,33,50,75].

Some institutions, such as the Ministry of Education, Rwanda Environment Management Authority, Rwanda Utility Regulatory Agency, Rwanda Standard Board, and Rwanda Development Board, are part of the institutional framework but, as Figure 4 shows, they have not to be assigned any active role in the policy actions related to household sanitation. For example, the Ministry of Education is part of a group of institutions assigned to the construction of toilets at schools, raising awareness of e-waste management, and supporting research and innovation on industrial waste and pollution, while leaving out research on household wastewater management. On the other hand, the Rwanda Standard Board, together with other institutions, is assigned to enforce the industrial effluent discharge standards and the establishment of industrial waste treatment facilities, leaving the responsibility of practical solutions to households. Additionally, households were not assigned to any policy actions, thus creating ambiguity around their role in improving sanitation at their own homes.

The Ministry of Infrastructure, Kigali City Council, and Development Partners play a crucial role in policy implementation due to their responsibility for numerous policy actions. However, when policy actions are assigned to institutions whose primary focus is not sanitation, they will likely be deprioritized. Additionally, unclear role boundaries make it challenging for these institutions to allocate budgets for such actions.

3.4.2. Regulatory Framework

Twenty-three government publications related to the regulatory framework for sanitation were reviewed, covering laws, policies, regulations, national and sectoral strategies, standards, and guidelines. The key features of these publications related to sanitation in Rwanda and Kigali are summarized in

Table 7. Key features of regulatory framework for sanitation in Rwanda.

Name of Publication (Year)/Leading Institution	Key Features Related to Sanitation
Laws
Constitution of the Republic of Rwanda (2023)/Prime Ministry	Law that gives citizens the right to a clean environment and a duty to protect, safeguard, and promote the environment
Law N° 48/2018 of 13 August 2018 on Environment (2018)/Prime Ministry	Law that determines the procedures for the conservation and promotion of the environment, including liquid and solid waste management
Law N° 10/2012 Government urban planning and building in Rwanda (2012)/Prime Ministry	Law that seeks to protect the physical environment, improve water drainage across roads, and protect water resources from pollution. Stipulates that sewage must be collected in treatment factories for purification
National Strategies
Rwanda Vision 2050 (2020)/Ministry of Finance and Economic Planning	Strategy to achieve high-quality standards of living and safely managed sanitation services; 80% by 2035 and 100% by 2050
National Strategy for Transformation I (2017–2024) (2017)/Ministry of Finance and Economic Planning	Strategy to raise improved sanitation access to 100% (by 2024), by investments in standards for household toilets, centralized sewerage and sludge treatment in Kigali, semi-centralized systems in settlements, upgrading sewerage in estates, and modern landfills for waste management.
Transformation II (2024-2029) (2024)/Ministry of Finance and Economic Planning	The Kigali Centralized sewerage system will be completed. Households and communities will be mobilized to continuously adopt safe and modern sanitation practices; tailor-made sanitation solutions for different households will be promoted.
Regulations
Regulations on Decentralized Wastewater Treatment Systems (2016)/Rwanda Utilities Regulatory Authority	Regulates the operational components of decentralized wastewater treatment systems, including licensing for service providers, pre-design and design criteria, system location, sewage installation standards, acceptance of work, discharge levels, and O&M requirements.
Policies
National Water and Sanitation Policy (2023)/Ministry of Infrastructure	Policy on ensuring sustainable, reliable, and affordable access to safe sanitation for all, by promoting basic household sanitation, capacity of the private sector, mixed use of financing, enabling environment for sewered and non-sewered sanitation, and sanitation facilities for wastewater and fecal sludge.
National Policy on Environment and Climate Change (2019)/Ministry of Environment	Policy on creation of a clean and resilient environment, by circular economy, private sector investment in sanitation technologies and infrastructure, and resource recovery.
Health Sector Policy (2015)/Ministry of Health	Policy on improving disease control, by hygiene promotion, enhanced health determinants, and decentralized hygiene inspection.
National Urbanization Policy (2015)/Ministry of Infrastructure	Policy on improving urban infrastructure for quality of life and equity, by liquid waste removal and treatment, solid waste management, technology use, hygiene promotion, and protection of environmentally sensitive areas.
Decentralization policy (2012)/Ministry of Local Government	Policy on promoting transparency and accountability for local service delivery through citizen participation in planning.
Sectoral strategies
Sustainable Water, Sanitation and Hygiene Finance Strategy (2022)/Ministry of Infrastructure	Strategy supporting stakeholders in the WASH sector to finance activities to reach Vision 2025, NST1, and SDG sanitation targets, including options to reduce costs and mobilize additional funding.
City Development Strategy (2018) and Kigali Master plan (2020)/Kigali City	Strategy for construction of sewage treatment plants; a centralized sewerage system in Kigali (starting in 2025) and a fecal sludge treatment plant to replace the current dumping site (started in 2023).
Urbanization and Rural Settlement Sector Strategic Plan (2018)/Ministry of Infrastructure	Strategy to achieve human settlements with access to infrastructure, utility services, upgraded and prevented informal settlement, high quality of water, good sanitary conditions, and proper waste management.
Standards
Rwanda Standards (RS) ISO 24521: Guidelines for management of basic on-site domestic wastewater services [76]	Standards on onsite domestic services related to public safety, occupational health and safety, environment protection, and sustainable development. Covers components, planning and construction, management, O&M, and sustainability.
Rwanda Standards ISO 30500: Non-sewered sanitation systems- prefabricated integrated treatment units- General safety and performance requirement for design and testing [77]	Standards for non-sewered sanitation systems, including user requirements, design capacity and lifetime, performance and operational conditions, sanitation system components, operation and management, and technical and mechanical requirements.
Guidelines
Practical guidelines on the construction of emptiable latrines for low-income communities in the city of Kigali (2023)/City of Kigali	Guidelines for technical and financial details on types of latrines, to guide households in choosing emptiable and cost-effective latrines.
Guidelines for Inclusive Urban Sanitation Service Provision (Incorporating Non-Sewered Sanitation Services) (2020)/Eastern and Southern Africa Water and Sanitation Regulators Association	Guidelines outlining sanitation technologies regarding applicability, design criteria, and O&M requirements, including proposal of minimum standards and indicators for operational components.
Guidelines for Fecal Sludge Management (FSM) (2020)/Rwanda Utilities Regulatory Authority	Guidelines for stakeholder responsibilities, minimum design criteria, and O&M, as well as guidance on administrative components and minimum standards for operational components.
Instruction for Latrine Construction 2018 (2018)/Ministry of Health	Guidelines for the construction of a solid latrine slab, including instructions on the construction and use of a basic latrine.
Booklet of latrines and hygiene technologies (2018)/Ministry of Infrastructure	Guidelines for selecting criteria for toilets and technical standards for latrines and septic tanks, including construction materials and estimated costs.

.

The reviewed government publications in Table 7 shows that the national sanitation sector in Rwanda is guided by four leading strategies: Rwanda Vision 2050, SDG 6 2030, National Strategy for Transformation I and II (NST I and II) [78,79]. The same strategies guide sanitation in provinces, including Kigali. There is no specific sanitation law in Rwanda; however, the constitution provides essential facets that can allow the realization of the right to sanitation [80]. The constitution, together with laws on the environment, urban planning, and building, sets a protected environment and wastewater treatment as fundamentals to citizens’ welfare. This is furthermore translated into the national and sectoral strategies, which set long and short-term goals, paving the way to sanitation rights.

However, a comparison with status of access to sanitation (Table 1 and Table 2) and the current FSM service chain situation (Figure 3), shows that progress is slow. For example, Vision 2050 targets achieving 80% safely managed sanitation; however, this indicator is not being monitored as such (Table 2 and Table 3). Additionally, NST1 aimed at achieving 100% coverage of improved sanitation services, but in five years in Kigali the progress was only from 41.7% to 48% for improved, not shared facilities. In line with NST1, there was a plan to construct a centralized FS treatment plant, which was accomplished. NST2 plans to continue this progress without setting a clear paradigm shift, by driving sustainable and faster achievement compared to NST1 [78,79]. The overlapping responsibilities seen in Figure 4, together with limited sector funding, could be potential explanations for the slow achievements.

The five policies related to sanitation presented in Table 7 provide directives ranging from household infrastructure to services, including treatment and environmental protection. The national water and sanitation policy of 2023 outlines key actions that seek to improve access and services. However, it is not significantly different from the policy actions of the previous policy. Moreover, the policy seeks to raise basic and safe sanitation facilities, which in the context of Kigali may be contradictory to the city master plan, mainly because basic sanitation does not provide safely managed FS by either definition. Furthermore, other policies have similar objectives, and this may create collusion, duplicate planning, and impede implementation. For example, the policies for water and sanitation and urbanization both aim at ensuring wastewater management. Similarly, hygiene promotion is addressed in the policies for both water and sanitation, urbanization, and the health sector.

In terms of sectoral strategies, the urbanization and rural settlement strategy includes robust measures to upgrade informal urban settlements, which numerous studies highlight as facing severe sanitation challenges, particularly in Kigali [15,16,17,80]. This sectoral strategy and the Kigali Master Plan strategy are aligned with the national strategies and policies, which all have ambitious targets compared to the achievements, as about 93% of the WASH budget is invested in water supply and the remaining 7% is distributed to sanitation, hygiene, and water resource management [35]. For example, both policies and strategies mention constructing FS treatment facilities and increasing sewers; however, neither were reported as completed, and the FS treatment has only started.

In 2019, the Rwanda Standard Board (RBS), intending to standardize onsite sanitation systems, adopted the two [76] and [77]. However, these standards are not referred to in any of the policies and no related guidelines have been developed after they were adopted. Additionally, four guidelines for sanitation facilities were developed from 2018 to 2023. The guidelines for Fecal Sludge Management published by the Rwanda Utilities Regulatory Authority (RURA) in 2020 are similar to the Guidelines for Inclusive Urban Sanitation Service Provision published in 2020 by the Eastern and Southern Africa Water and Sanitation Regulators Association (ESAWAS), such as in proposals for types of onsite technologies, operation, and maintenance, treatment and disposal, licensing service providers. This resemblance suggests that there is potential for regional collaboration in addressing urban sanitation issues. The practical guidelines on the construction of emptiable latrines for low-income communities in Kigali, published in 2023 by the City of Kigali, and the Booklet of Latrines and Hygiene Technologies, published by the Ministry of Infrastructure, also have similar content on proposed onsite technologies, and they are both in line with the guidelines published by RURA. The publication of similar content by different institutions suggests a duplication of efforts and responsibilities, identified by different studies as a result of inefficient assignment of responsibilities and duplicated objectives in policies and strategies (Figure 4).

The challenges in the FSM at households can be attributed to the duplication of regulations from different institutions, a lack of enforcement, and limited coordination of efforts from institutions [13,15,16,17,33,41,43,58]. In addition, efforts are scattered among different stakeholders, and regulation enforcement is limited, potentially leading to limited impact. Moreover, a general feature that can be seen regarding emptying services regulation, is that, like in many other African countries, authorities prioritize sanctions over regulatory mechanisms. In Kigali, rules, monitoring, and evaluation have been found to be extensive; while sanctions are partially in place and implemented, support and incentives are limited, pro-poor mechanisms do not exist, and the accreditation process of service providers is long [81]. In their study conducted in Rwanda, including Kigali, [82] found that poorer and less educated families are less likely to gain admittance to sanitation facilities than wealthier and more educated families, thereby highlighting socioeconomic disparities in access to sanitation and promoting pro-poor strategies. Lastly, the review of regulations shows that the role of households and landlords remains unclear. For example, while households make up the majority of sanitation services end-users, their contribution remains unclear in both regulatory and institutional frameworks, and they are often left to their own to decide how to manage the FS they generate.

The recommendations by the reviewed publications to improve sanitation governance in Rwanda are synthesized in

Table 8. Synthesis of recommendations from the reviewed publications to improve sanitation governance in Rwanda.

Recommendations	Source
Enhance the enforcement of regulations and laws to accelerate improved services	[13,15,16,17,33,41,43,55]
Set clearly defined responsibilities and roles for institutions to improve coordination and efficiency while promoting autonomy in decision-making for institutions and reducing fragmentation of responsibilities	[13,16,17,33,50]
Improve the integration of WASH in strategy development, implementation, and service delivery	[21,35,55,82]
Prioritize sanitation and improve sector funding mechanisms to match the ambitious policy actions	[16,54,75]
Enhance regulation to attract private funding by incorporating supportive incentives and pro-poor mechanisms	[80,81,82]
Improve governance on the development and implementation of quality sanitation facilities to improve the quality of access coverage	[14,41]
Develop, invest in, and regulate a supply chain to generate innovative pathways that are economically, socially, and environmentally sustainable, promoting safe treatment and disposal, as well as waste minimization and recycling	[12,50]

.

4. Discussion

4.1. Key Challenges

This study aimed to review scientific and government publications from 2013 to 2024 on household sanitation in Kigali to identify gaps and improve services. The review of the 68 included publications, including 36 scientific and 32 government publications, revealed that the FSM at households in Kigali has critical challenges but also opportunities, which are discussed in this section.

Findings indicate that most onsite sanitation facilities used in households are of poor quality, unsustainable, inconvenient for users, and difficult to service. Proper containment and interface are important parts of the first stage of a sustainable FSM service chain [1,3], but in Kigali, the majority are of poor quality and shared with other households. This is critical as they are difficult to empty and can be a source of diseases and infections for households and sanitation workers [25,48,57,83]. Moreover, when toilets do not prevent contact between humans and excreta, or when the containers leak into the environment or are at high risk of collapsing, they pollute the environment and can transmit diseases and cause accidents. In the case of Kigali, such containment could potentially contribute to saturating the soil, which, once exacerbated by climate events such as heavy rain, could lead to deadly landslide disasters and contamination events, which are common in Kigali.

In Rwanda, transmitted diseases include diarrheal infections and NTDs, which commonly are known as among causes of malnutrition among young children [59,67,71,72]. Limited access to sanitation is among the primary causes of NTDs [60,84] and has been linked to Antimicrobial Resistance [25,85]. The pathogens that pose health issues are different types of bacteria, viruses, Protozoa, and helminths, which are transmitted through different routes, including direct contact, vectors, polluted water, and contaminated soil [1].

The sanitation market is driven more by suppliers than by clients’ needs, resulting in a limited set of solutions which leads people to choose inconvenient but easy solutions. For example, in dense settlements, people use the only type of toilet they know; traditional latrines; even though they are found uncomfortable, without privacy, difficult to clean, with high risks of accidents, and unsafe for women, children, and people with limited mobility. In addition, the poor quality of onsite facilities and the location of current disposal at Nduba landfill play an important role in the high cost of professional emptying services. Much time is spent trying to access pits, being cautious to avoid pits collapsing, removing solid trash mixed with FS, and transporting it long distances to the dumping site [23]. Moreover, high standards and regulations for emptying services compared to ground situations are a barrier to inclusive service delivery for both service providers and households [45]. In comparison to solid waste management services, emptying pits is not a scaled-up service in Kigali [17,53]. The missing or non-functioning stages of the FSM service chain in Kigali (Figure 2) are critical for a viable sanitation service, environmental protection, and public health-related outcomes. Although the Nduba landfill is a licensed site, it does not safely treat or dispose of the sludge. No significant operational capital is invested there; therefore, the currently limited demand for emptying does not affect its operations, which may not be the case for centralized treatment plants under construction.

When adequately treated to meet standards for pathogens and other chemicals, FS can be a valuable resource for agriculture and cooking energy production. However, when treatment standards are not met, using FS as fertilizer poses health risks to farmers and consumers. It can also pollute soil and water sources through the transmission of pathogens and harmful chemicals [84]. For example, in Nyamagabe, Rwanda, treated and dried fecal sludge from a decentralized FS treatment plant is used as an income-generating resource in the production of briquettes and bio-fertilizers, which are said to meet standards and are socially accepted [86]. However, this practice is disputed in Sweden, where some stakeholders see the resource recovery of FS in agriculture as beneficial, while others raise social acceptance and safety concerns about harmful substances contained in FS, such as microplastics and heavy metals, which are difficult to remove and monitor [84,87]. Additional coordination is needed at the policy level to address the non-functional stages of the FSM chain in Kigali, including the acceleration of the construction of the treatment plant, potential for reuse, and the development of sustainable business plans.

The distribution of responsibilities to different institutions and assigning policy actions to multiple entities suggests that there might be opportunities in adopting a hybrid policy implementation, which can be the best approach if well-developed [38,88]. Overlapping policy responsibilities can result in inconsistent coordination, a lack of accountability in enforcement, and obstruct the advocacy for or implementation of a multifaceted funding mechanism [74,80]. This will complicate both funding initiatives and enforcement and can lead to low prioritization and limited technical capacity [16]. For example, the WASH sector experiences approximately an annual financial gap of USD 316 million (320 billion Rwandan francs) to achieve Vision 2050, NST1, and SGD 6, and annually only about 7% of WASH budget is assigned to sanitation, hygiene and water resource management, with the remaining 93% going to water supply [35].

The strategies in the sanitation sector provide general guidance and ambitious targets in sanitation but fail to contextualize those targets, especially in dense settlements and middle-class households that comprise Kigali’s population. Not addressing the diverse settlement issues contributes to a restrained sanitation market. Properly assigning policy responsibilities and contextualizing sanitation solutions can contribute to addressing unsustainable policy implementation and market issues. For example, the new Water and Sanitation Policy of 2023 has included Gender Equality and Social Inclusion (GESI) among cross-cutting issues and provides incentives for some materials targeting poor and vulnerable households to accelerate access to improved sanitation [7,18]. In addition, the review of indicators showed that there are inconsistencies between targets in strategies and indicators, which can contribute to unsustainable urban sanitation services [9]. For example, the use of a flush toilet in Kigali is considered an improved facility regardless of where it discharges and the number of people sharing it.

The overlapping responsibilities also cause institutions to publish similar guidelines, which in turn do not lead to widespread adoption due to insufficient dissemination and enforcement. For example, setting high standards for emptying services without addressing the issue of containment and their location does not contribute to enhanced services. Consequently, the gaps in the institutional framework negatively influence the functionality of the regulation framework. With such gas in both frameworks, the likelihood of households having access to quality sanitation facilities and enhanced FSM services is limited. As these services are vital in people’s daily lives, they tend to find solutions on their own, which does not always lead to good outcomes.

4.2. Comparison with Other Studies in African Cities

The use of OST is quite common globally and especially popular in Sub-Saharan African countries, where more than 439 million people depend on them [2]. The situation of poor quality and a non-functioning FSM chain is not an isolated case for Kigali [89,90]. In some cities, such as Lusaka and Cape Town, FSM-related regulations are not implemented due to various factors, including knowledge, resources, and motivation among stakeholders [6]. Duplication of responsibilities among institutions also appears to be a shared issue in East Africa and a contributor to sector-limited funding [14,74]. However, Rwanda stands out for making progress, albeit mainly in rural areas, due to the government’s high political will. For example, Rwanda has been among the countries that have quickly eradicated open defecation [12,13,80]. Translating policies into practical actions, assigning responsibilities to institutions, and investing in the entire FSM service chain; rather than focusing solely on constructing a sewer or treatment plant and neglecting toilets, containment, and behavior changes; can improve urban sanitation, especially in Kigali, which already has a regulatory framework, strong institutions, and political will in place [74,88,91]. These strengths, combined with effective sanitation marketing, could enhance safely managed sanitation in Kigali. For example, other developing countries in East Africa, such as Uganda and Kenya, have demonstrated significant progress in developing contextualized sanitation markets and businesses for OST [80,92], which can serve as good examples for Rwanda. As with many countries, there is a need to think beyond business as usual while planning urban sanitation.

4.3. Recommendations for FSM in Kigali

The analysis of the findings and comparison with conditions in other cities shows that there are synergies that can be leveraged to enhance the effectiveness of FSM in Kigali to provide better services. Figure 5 highlights prioritized recommendations for enhancing households’ FSM services, based on the identified issues, initiatives, and synergies. Key components include ensuring the availability of an institutional and regulatory framework, short and long-term strategies, and the capacity of households to pay for affordable services. Addressing the gaps found in the institutional and regulatory framework can pave the way for a well-coordinated sector, integrating key stakeholders and increased funding. Such strategic reform can contribute to adaptive regulations, enforcement, and sanitation services delivery that encompasses the current and future needs of households.

The priority recommendations can be catalyzed by implementing a strategic and purposeful awareness campaign across communities, policymakers, implementers, civil society, the private sector, and academic circles about the importance of proper design, construction, and operation of domestic sanitation facilities and treatment plants. Such awareness should promote public health, environmental protection, and sustainable access to safely managed sanitation in Kigali.

4.4. Limitations and Future Research

One limitation with this study was that, due to limited literature, it focused on the citywide situation in Kigali and did not evaluate conditions in different settlements in any detail. For the same reasons, the status of guidelines and standards implementation, the FS containment type, and detailed analysis of DWWSs use were not reviewed. Still, limited information on DWWSs has allowed a general analysis. Furthermore, the data in the literature were not consistently aligned from study to study, which prevented a comparison between some of the findings; instead, simple descriptive statistics were used to analyze the changes to indicators, instead of a thorough causal analysis. Quality assessment of included sources was conducted to minimize bias. However, potential for bias may arise from the exclusion of data published outside the period set for this review, which could have provided additional insight or perspectives. Considering the results and these limitations, future studies should focus on the impact of poor sanitation on health, currently used technologies in different settlements, adapted onsite and decentralized sanitation technologies, and sanitation financing solutions.

5. Conclusions

This study reviewed 68 publications that contained information on households’ FSM in Kigali. Results from the consulted publications were aggregated in the following four main themes: (1) access to sanitation, (2) Fecal Sludge Management service, (3) public health, and (4) sanitation Governance.

The findings indicate that households’ FSM situation in Kigali faces challenges related to poor quality sanitation facilities, dysfunctional FSM, duplication of responsibilities among institutions for policy implementation, limited sector funding and private sector involvement, and sanitation-related public health issues. Common issues highlighted in this literature include the high cost of emptying services, inaccessibility of pits by exhaust trucks, and poor hygienic conditions of toilets, such as dirtiness, fullness, bad smells, and lack of privacy. Additionally, challenges such as the unsustainability of toilets and sharing facilities between households, along with non-client-centered market dynamics, were found to be critical. The results reveal that the FSM situation of households in Kigali is a multifaceted issue that, if left untreated, could lead to increased public health and environmental pollution challenges over time. Based on the identified issues, initiative, and recommendations from the reviewed publications, five components were identified as key drivers for enhanced and sustainable household FSM: (1) enhanced governance and role clarity, (2) coordinated planning and policy integration, (3) regulation adaptability and standards enforcement, (4) public–private collaboration and investment, and (5) enhanced holistic FSM service chain management. Through synergies with these components, recommendations were identified and assigned to specific authorities. Further studies to advance the knowledge of FSM in African cities facings similar conditions as Kigali should focus on the impact of poor sanitation on health, currently used technologies in different settlements, adapted onsite and decentralized sanitation technologies, and sanitation financing solutions.