Poor fecal sludge management (FSM) results in significant public health and environmental risk exposures. To understand the FSM patterns and future scenarios of Kombolcha town, qualitative and quantitative methods of data collection and the Shit Flow Diagram (SFD) data analyzing tool were used. The study showed that 75.7% of households rely on shared toilets with two and above households. Cistern flush toilets, pour/manual flush toilets, ventilated improved pit latrine, pit latrine with slab and pit latrine without slab are the main technologies practiced in the town as 2.1, 19.8, 11.1, 56.4 and 10.6 %, respectively. 98.5% of the toilet types were unlined or only partially lined. On the other hand, only 37% of households practice toilet pit or sludge tank filling up and emptying. It was also found that only 56% of fecal sludge was safely managed. The remaining 44% of excreta is disposed in a way that it poses environmental and public health risk. Thus, current fecal sludge management trend exposes the community’s health unless sanitation bye-laws and building code regulations are set to address the quality of toilet technologies that promote hygienic standards.
Research Article
Excreta Flow Mapping along the Sanitation Service Chain, A Case of Kombolcha Town, Ethiopia
https://doi.org/10.21203/rs.3.rs-2105336/v1
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Fecal Sludge Management
Onsite Sanitation
Risk Exposure
Sanitation Service Chain
Shit Flow Diagram
Worldwide, 1.1 billion people practice open defecation and many more do not have services that prevent fecal waste from contaminating the environment. About 2.3 billion people, who still required a basic sanitation service, either use unimproved services or practice open defecation. Similarly, millions use limited sanitation facilities that are shared or communal to households [1]. On the other hand, around one billion onsite sanitation technologies serve worldwide in urban areas [2]. However, the typical on-site management system is the accumulation of feces in heavy slime [3]. Fecal sludge without proper management is normally allowed to accumulate in improperly designed holes and drainage canals or dumped into waterways, and resulting in extensive environmental and public health risks[4].
A lack of safe sanitation systems leads to infection and disease, including diarrhea [5]. A leading cause of disease and death in children under five years in middle and low-income countries [6] are neglected tropical diseases such as soil-transmitted helminth infections, schistosomiasis, and trachoma that cause a significant burden globally [7]; and Vector-borne diseases such as West Nile Virus, lymphatic filariasis and Japanese Encephalitis [8] through poor sanitation facilitating the proliferation of Culex mosquitos.
One in three households in Ethiopia has no toilet facility; defecate to bush/fields (39% in rural areas and 7% in urban areas) [9]. As a result, diarrhea contributes to more than one in every ten child deaths in the country[10]. The situation in Kombolcha town is not diffrent. At present, overflow & leakage of pits, illegal pit/septic tank outlet connections to drainage canals, and water bodies are the main problems. These, together with other unsanitary circumstances such as open defecation practice, lead to extremely serious environmental and community health hazards. To overcome the fecal management limitations the study area, research on entire fecal sludge management gaps along the sanitation delivery chain from containment up to end disposal/reuse is paramount importance. Thus, this research was conducted to map excreta flows from containment up to end disposal to show the related management gaps at each stage of the service chain and to provide baseline data for future intervention stratagic planning.
2.1 Study Area
The study was conducted in Kombolcha town of Ethiopia, involving all the six administrative districts of the town. The urban center population was estimated at 110,654 with a total of 22,984 households [11]. The geographical location of the town is about 110 6' N latitude and 390 45' E longitude and it is found at about 377 km north of Addis Ababa, the capital city of Ethiopia. The altitude ranges from 1842–1915 m above sea level. The mean annual rainfall varies from 725.1 mm to 1361.6 mm and the mean annual temperature varies from 18.7 to 20.9°C [12].
2.2 Research Design
The onsite sanitation containment system is categorized into a containment system, where fecal sludge (FS) is contained, and a feacal sludge, which is not contained in a system. Fecal sludge is considered as not contained when the faecal sludge percolates into the ground and contaminates the high groundwater table or if the faecal sludge from the septic tank or pit latrine flows through open-drain/water body/open ground. Whereas the fecal sludge is considered as contained when the sanitation technology and/or system which ensures a safe level of protection from excreta [13].
The research design is primarily based on the Shit Flow Diagram (SFD) tool that already exists and processed by the Shit Flow Diagram Promotion Initiative (SFD-PI) which is found under the set of diagnostic tools developed by the World Bank [14]. Thus, the framework for data collection was based on the SFD methodology framework for FSM diagnostics [14]. This SFD methodology was selected because the study focused on fecal sludge management and SFD is a current worldwide advocated and systematic way of fecal sludge management assessment tool. The SFD tool helps to understand the current FS management patterns and future scenarios.
The study was based on household surveys, field observation, key informant interviews (KII), and focus group discussions (FGD) data collection instruments.The household survey was conducted to determine characteristics and faecal sludge management (FSM) arrangements of households. Questionnaires were developed with 58 questions and 25% of answers were gathered through observation by enumerators.
The quantitative data collection was carried out in three phases. The first phase involved in selecting a stratified sampling method to draw sample households. A list of forty (40) wards was collected from all the 6 urban districts together with their respective number of population and households. In cases where adjacent wards were found to be similar in terms of population density, land use composition, and built-form, they were merged to generate a cluster after reconnaissance survey. Thus, nine (9) clusters were identified for this study. In the second phase, the sample size was determined by considering financial constraints, time, the purpose of the study, and representativeness.
The sample size was estimated using the expression given by [15]:
Where, n = the required sample size; N = Total number of household units; Z = standard normal deviation; e = sampling error; P = the proportion of targeted population. The number of households was obtained from the Kombolcha town administration council and the total number of households was 22984. Therefore, with a 95% confidence level, ± 5% precision, and 80% proportion variability the drawn reliable minimum sample size of households was n = 243.
In the third phase, the total households sample size of 243 was distributed over the 9 clusters based on their population size as 17, 18, 37, 22, 12, 50, 51, 27 and 9 sample households. Finally, the sampling was drawn using a simple random sampling method after translation of the questionnaires into the local (Amharic) language and pilot tested for validity.
On the other hand, in a qualitative study, purposive sampling was conducted for stakeholder identification and key informant interview process. Appropriate checklists were established and 24 key informant interviews (KIIs) were conducted with different stakeholders from the government and non-government organizations. Those key informants were from vacuumed truck drivers, the water supply and sewerage service office, Kombolcha town municipal authority, Kombolcha town health department, sanitation and beautification department, Kombolcha town health extension workers, faecal sludge treatment plant supervisor, faecal sludge treatment plant (FSTP) attendants, septic tank or pit latrine installers/masons, and public toilet attendants.
Visual inspection and observations were embarked along each stage of the sanitation delivery/service chain, from household containment up to treatment or disposal of fecal sludge, to determine the technical requirements of siting sanitation facilities. Transect walks were made in the four selected zones of the study area as well as informal and informative interviews were carried out using a checklist with the respective zonal leaders. These were systematic walks aimed at observing the way and manner cesspit emptier discharge the sludge at the disposal site and also to check the frequency at which they go there, methods used for end-use/disposal of FS, location of water supply source from disposal sites, access for emptying services to pits, septic tanks, risk exposures along the service chain, and sanitation system technologies distribution over the town.
Besides these, overall, two focus group discussions (FGD) sessions were held and conducted at the end of the field-based research. The sessions were limited to two because of resources constraints. The quantitative data collected through a household survey concerning containment technologies were readjusted, especially illegal toilet outlet connections that cannot be addressed through the household survey. Likewise, the FGD topics were focused on to obtain data related to household practices, service levels, past interventions, risks, and other issues associated with fecal sludge management services. Those topics were based on fecal sludge management global study data collection instruments [16].
2.3 Data Analysis and Ethical Considerations
Data analysis was performed in two stages. First, a combination of quantitative and qualitative data was pre-analyzed, that is the collected quantitative data were analyzed using Statistical Package for Social Science (SPSS) and Micro Soft Excel for the preparation of data input. After completing data input, the data prepared as a tabular form were analyzed through the description, narrating, and contextual interpretation.
Secondly, the pre-analyzed quantitative data with Micro Soft Excel and SPSS tools were prepared for further analysis with the Shit Flow Diagram (SFD) analyzing tool. As detailed by Scott, [16], SFD is an advocating tool that signifies where the faecal waste ends up, what proportion is efficiently managed, and where the unmanaged portion is delivered. Furthermore, SFD provides a convincing visual summary by highlighting at which stages the fecal waste becomes ineffectively and effectively managed flows for a given population [17]. Thus, the excreta flow was mapped/analyzed from point of defecation to end-use or disposal using the SFD tool with color representation outputs, in which red and green were used to represent unsafely and safely managed excreta, respectively.
For the research ethics, a, written research permit with BiT academic council BiT Senate No 10/2012 on Feb. 27/2020, was granted by Bahr Dar University of Ethiopia. At the residential house level, the aim of the study was enlightened and oral consent was sought after explaining the aim of the study. Interviewees were free to withdraw or terminate the interview at any time they want and able to choose any questions to answer.
3.1 House and Toilet Occupancy
Out of the 243 representative sample households, 69.1% had their own house. This result was not obtained by asking the respondents randomly from multiple housing compounds, rather than landlords were the primary choice in the household survey aiming to gather reliable and strong information concerning fecal sludge management arrangements. Besides, 11.9% of tenants were interviewed where the landlord didn’t avail him/her self during the survey. In total, 81% of residential houses were engaged by landlords but most of them have a rental classroom within their compound. The remaining 19% of residential houses were occupied by tenants of government-owned houses, out of which 46% were shared house owners.
In contrast, the household survey outcome showed that 24.3% of the respondents had access to private household toilets and 75.7% of Kombolcha town inhabitants rely on shared toilets between 2 or more households. This is because of the increase in the construction of rental rooms tightened with living house with common toilets to generate income, following the need for housing in the town. So, out of 75.7% of shared toilet user households, 60.1% was shared between landlords and their rented house households (tenants). The remaining 15.6% of households used communal toilets shared between tenants of government-owned houses and/or sharehouse owners. Public toilet user households and households without toilet facilities were neither observed nor reported during the household survey.
3.2 On-site Sanitation Technologies
The household survey results showed that there are five main types of household toilets technologies in Kombolcha town; namely, cistern flush toilets, pour/manual flush toilets, Ventilated Improved Pit latrine (VIP), pit latrine with and without slab (Error! Reference source not found.). 56.4% of the residents use simple pit latrine with a slab; where as, cistern flush toilet, pour/manual flush toilet, VIP latrine, pit latrine with slab and pit latrine without slab technologies were used as 2.1, 19.8, 11.1 and 10.6%, respectively.
There was no currently existing data on the Kombolcha town’s toilet technology type basis, except the data from central statistical authority, CSA, [18]housing units and their respective types of toilet facility, which showed of all the Kombolcha town housing units, 23% have no toilet facility; whereas, 5.6, 11.6 and 59.8 of them have shared or private flush toilets, VIP latrines, and pit latrine technologies. Thus, the present findings are not in agreement with the CSA report, spectially for the no toilet facility and flush toilets categories. However, the study result of the study is almost the same as that of the CSA report for the housing units with VIP latrine.
As shown in Error! Reference source not found., 71.1%, which is about three-fourth of Kombolcha town inhabitants, use pit latrine technologies including VIP latrine. However, septic tank users were significantly low, at 21.9%, compared with pit latrine users.
According to WHO and UNICEF [1] Sustainable Development Goal (SDG), improved sanitation facilities are categorized as safely managed, basic, and limited facilities. Improved facilities that are not shared count as either basic or safely managed services. The estimated study result is presented in Error! Reference source not found..
| Type of facilities | Categories | Percentage |
|---|---|---|
| Improved facilities Unimproved facilities | Basic facilities (not shared with other households) | 17.3 |
| Limited facilities (shared between two or more households) Use of pit latrines without a slab | 72 10.7 |
On the other hand, open defection is time and again encountered in Kombolcha town and it has been practiced mainly by the homeless, as they do nothave sanitation facilities. Discussion with community members together with observations during field survey showed that open defecation is practiced in almost all parts of the town, especially the older districts: either by newcomers from remote areas for a work opportunity or market exchange purpose. Even though the current open defecation practice is expected to even ger worse, the extent could not be determined due to lack of census data or a reasonable estimated number of people who practice open defecation. For the tenacities of this study, it is considered to be 7% which was estimated by WHO & UNICEF [1] as a country level for Ethiopian urban areas.
The FGD and KII showed that government owened individual rental house communal toilet users of slum areas share one seat for 25–30 households whereas households sharing the rental houses one seat for three households. The transect walk in vulnerable areas and observation during HHs survey showed poor management of the facilities, such as infrequent cleaning and desludging of the facility, and poor maintenance practices related to the dense population settlements that make the management difficult. Commonly frequent filling of tanks and pits together with long waiting time to get emptying service results in a health risk exposure.
3.3 Risk of Groundwater Contamination
Due to the lack of available groundwater maps or recorded statistics concerning the actual groundwater levels of the town, the estimations were made based on, HH survey, literature review, and key informant interviews. The risk of groundwater pollution was calculated using the SFD graphic generator groundwater assessment helper tool. The risk of groundwater pollution was estimated from data on drinking water from private groundwater sources, vulnerability of the aquifer, and the distance between groundwater sources and sanitation facilities. Among the 243 sampled households 3.7% of them own groundwater sources for multiple purposes except for drinking as tap water is available from the municipality and identified as a low risk of groundwater pollution. However, 3.2% of the population live in areas with a significant risk of groundwater pollution.
3.4 Containment System Estimations
Analysis of the interview statements, FGD, household survey, and visual inspection during the HHs survey result leads to the following quantitative estimations for onsite sanitation technologies and their respective containment systems except, 7% country-level open defecation practice based on WHO and UNICEF [1] estimation. Those estimations were gathered by taking into account the official survey report's underestimation and the household’s intolerance to admit their illegal practices. Thus, more weight was given to interview statements, especially for illegal toilet outlet connections and related issues. However, the estimations were challenging, as a lot of different systems exist in the town that differ from SFD system terminology for both tanks and pits. As a result, there was a need for grouping of similar technologies into SFD system terminology categories, for both tank and pit latrine systems, as shown in Error! Reference source not found..
| Containment technologies | Estimations (%) |
|---|---|
| Fully lined tank, no outlet or overflow | 1.5 |
| lined tank with impermeable walls and open bottom, no outlet | 10.0 |
| Lined/partially lined tank discharged to open drain/water body | 9.5 |
| Lined pit/tank with semi-permeable walls and open bottom, no outlet | 46.0 |
| Unlined pit with no outlet or overflow | 11.0 |
| Pit latrines abandoned when full and covered with soil, no outlet | 8.0 |
| Pit latrines abandoned when full and covered with soil, no outlet or overflow in significant GW risk areas | 3.2 |
| Containment failed, damaged, collapsed, or flooded - no overflow | 3.8 |
| Open defecation | 7.0 |
The study findings show that 98.5% of the on-site sanitation technologies effluents are discharged to partially lined or compeletly unlined containment systems (Error! Reference source not found.). Out of these, 11.2% and 3.8% were fully abandoned and damaged/collapsed pits, respectively. 3.2% of containments were likely the major causes of groundwater pollution through which the faecal sludge infiltrates into the ground.
3.5 Faecal Sludge Emptying
The municipality has one vacuum truck of 8 m3 capacity and the governmental university campus in the town, Wollo University, has also one vacuum truck, which provids service for the University itself only. Neither the municipality can provide sufficient emptying services with the single truck nor are there any private trucks in the town to give the service. Instead, private vacuumed trucks come from a nearby town called Dessie, which is located at about 23 km fro Kombolcha, on request with a capacity ranging from 6 to 10 m3. Based on the emptying service provider's interview and household survey results, it costs approximately $ 13 per trip to get the emptying services with the municipality vacuum truck, whereas private emptying service charge varies from $ 31 to 57, including to Kombolicha travel cost. However, the private company vacuumed truck operators pay only $ 5 per truck to empty the contents at the fecal sludge treatment plant.
The study finds out that, 37% of households were experienced in a pit/tank filling up. They emptied their facility and reuse it again. Among households that experienced with emptying practices, 5.8% responded to the occasions of pit overflow due to lack of emptying service when needed. On the other hand, 51% of those households reported that their pit/ tank emptying frequency was less than one year and 12.2% of the household’s emptying frequency was 4 and above years (8.9% in 4 to 6 years and 3.3% above 6 years). The remaining 63% of pits or tanks were determined as emptiable facilities that have never been emptied before, technologies that unable to empty, and emptiable technologies with illegal outlet connections. However, 78% of onsite technologies were emptiable (except open defecation, damaged/collapse, and fully abandoned pits) as shown in Error! Reference source not found.. Out of 78% of emptiable toilet facilities, 41% (78%-37%) was emptiable but not emptied before. Out of 41% of emptiable but unemptied technologies, 9.5% illegally connect their outlet into an open drain/water body. The remain 31.5% is contained and emptiable but not yet emptied technologies.
| Containment technologies | Estimations (%) |
|---|---|
| Fully lined tank, no outlet or overflow | 1.5 |
| lined tank with impermeable walls and open bottom, no outlet | 10.0 |
| Lined/partially lined tank discharged to open drain/water body | 9.5 |
| Lined pit/tank with semi-permeable walls and open bottom, no outlet | 46.0 |
| Unlined pit with no outlet or overflow | 11.0 |
| Pit latrines abandoned when full and covered with soil, no outlet | 8.0 |
| Pit latrines abandoned when full and covered with soil, no outlet or overflow in significant GW risk areas | 3.2 |
| Containment failed, damaged, collapsed, or flooded - no overflow | 3.8 |
| Open defecation | 7.0 |
3.6 Faecal Sludge Transport
There was limited evidence of vacuumed trucks dumping FS to land or parts of the town environment before reaching the treatment plant and fecal sludge being removed informally by households themselves. Also, it was observed that the FSTP was located only at 3 to 3.5 km from the center of the town, and its access road was suitable for haulage of FS during rainy seasons. Similarly, the municipality has a restricted measure for those discharging the FS into the environment instead of FSTP. Thus, by taking into consideration the above enabling situations, the whole FS removed from pits and tanks was considered as delivered to the fecal sludge drying beds but 90% was considered rather than taking 100% the perfect figure.
3.7 Faecal Sludge Treatment
Currently, Kombolcha has a liquid waste treatment plant with four main components; unplanted drying beds, maturation ponds, storage lagoons, and sanitary landfills. The plant is located in the lowland area, at about 3.5 km away from the town center and uphill of the Borkena River about 70 m away. According to Kombolcha town water supply and sewerage service authority [19], with a total of 12,733 17,822 and 21,602 m3 of fecal sludge have been transported from Kombolcha and its neighboring towns, for 3 successive years of 2017, 2018, and 2019, respectively.
Poor and damaged retaining and common walls, plant growth on the drying beds at rest, non-functional screening unit, and loss of periodic cake or dry fecal sludge removal are the current problematic situation of the treatment system. Furthermore, the vacuumed trucks empty the sludge onto the drying bed with dried sludge/cake. This situation results in the accumulation of rubble and trash, which clog the pore spaces within the sludge from draining the liquid, rewetting of the sludge and thus resulting in prolonged drying period.
Likewise, the efficiency of treatment at the fecal sludge drying beds was not determined and also the plant is not operating optimally. Thus, a figure of 50% treatment efficiency was used to produce SFD. This estimation was drawn based on SFD-PI [13] methodology for unknown data on the efficiency of the plant and limited evidence on an operation, self-judgments after repeated field visits as well as referring to previous SFD preparations [14].
Error! Reference source not found. presents the overall FS emptying of on-site sanitation technologies. The percentage values of emptying for each containment technologies were determined from containment types and their respective emptying practices. The evacuated containment technologies, their emptying practices and 50% treatment efficiency together with the percentage of the population using each on-site sanitation systems were employed to develop the shit flow diagram shown in Error! Reference source not found..
| Onsite sanitation technologies | % of all containments | Emptied faecal sludge (%) | faecal sludge delivered to FSTP (%) | |||
|---|---|---|---|---|---|---|
| Fully lined tank, no outlet | 1.5 | 1.50 | 1.30 | |||
| Lined tank with impermeable walls and open bottom, no outlet | 10.0 | 6.86 | 6.20 | |||
| Lined pit/tank with semi-permeable walls and open bottom, no outlet or overflow | 46.0 | 25.90 | 23.40 | |||
| Unlined pit with no outlet | 11.0 | 2.75 | 2.50 | |||
| Total emptied FS | 37.10 | 33.40 | ||||
As indicated in Error! Reference source not found., there is 93% coverage of on-site sanitation and 7% open defecation. The excreta flow diagram highlights that, 77% of fecal sludge contained onsite, which can be considered as safely managed at present, the situation is intended for change over time. Besides, there is an increase in levels of groundwater contamination risk due to increased reliance on poorly constructed unlined pits, resulting in soil saturation and groundwater table contamination. All these situations will contribute to a greater quantity of the unmanageable fecal sludge, with possibly increasing risk to the environment and public health. The study also found out 16% uncontained on-site sanitation technologies, in which FS infiltrates into the ground and pollutes the groundwater or FS from the technologies flow through open-drain/water body/open ground and potentially cause serious health and environmental hazards.
What is clear from the SFD is also that almost half, about 56%, of fecal sludge in the town is safely managed, that is effectively managed. Within 56% of effectively managed faecal sludge, only 17% of it passes through the sanitation service chain and thus considered as safely/effectively managed. Whereas the 39% of the fecal sludge that remains unemptied and remains within onsite sanitation technologies without risk to public health or environmental contamination through groundwater pollution or direct exposure was considered as effectively managed. Likewise, 44% faecal sludge, which is the unsafely managed portion, poses environmental and health risk exposures directly or by contaminating the groundwater sources. It is also shown that the households with a containment facility that could be emptied are only less than half, at 38%. Of these, only 17% of the emptied sludge reached the unplanted drying bed and thus safely treated.
In conclusion, three fourth of the households in Kombolcha town depend on shared toilets and the dominant toilet technology is a pit toilet with and without slab, which accounted for 67.1%. This is an unsustainable way of fecal sludge management that revealed the key principle of safe toilet management, design, construction, and use via separate households from excreta for both active and passive contact [5]. This situation deteriorates the environment and public health unless sanitation bye-laws and building code regulations are enforced. Standards of latrine construction and management must be set to address the required quality of service and to promote hygienic conditions.
In the containment and emptying stage, most of the onsite sanitation technologies facilities were partially lined or compeletely unlined. The actual faecal sludge management within the containment facility is highly influenced by the poor construction quality and the surrounding soil conditions, resulting in those tanks and pits functioning for several years without the need to be evacuated. As the town becomes more densely populated, related to the introduction of new industries, this practice will become progressively unsustainable as the soil’s absorption capacity is exceeded.
Furthermore, the developed Shit Flow Diagram (SFD) indicated 56% of fecal sludge is effectively managed of which only 17% of fecal sludge passes through the sanitation service chain and considered as safely/effectively managed. Unlike, the remaining 44% of faecal sludge is unsafely managed i.e. poses environmental and health risk exposures directly or by contaminating the groundwater sources. Lastly, insights from this study can inform to identify priority areas for the introduction of a range of sewerage options and the need to consider the use of well-designed septic tanks, anaerobic baffled reactors, or other amended on-site containment systems supported by more responsive faecal sludge management services. As well as future studies in service delivery assessment in conjunction with a public health risk assessment for intervention option planning is needed.
Author Contributions: Seid Endris conceived and developed the research framework. Tewodros Desale and Almayehu Ali undertook the data processing and analysis. Eshetu Assefa Wrote and revised the manuscript. Seid Endris and Andinet Kebede supervised and revised the manuscript. All authors have read and agreed to the published version of the manuscript.
Conflicts of Interest: The author declares no conflict of interest.
Availability of Data and Material
All data generated and analyzed during this study are included in this published article.
Funding Statement: -There is no funding Agency
Acknowledgments: The research was implemented under a collaborative partnership with the Bahir Dar University so the authors are would like to thank to these organizations for the financial and other support during this work. We also acknowledge the anonymous reviewers, whose comments greatly improved the paper.
- WHO & UNICEF, “Progress on Drinking Water, Sanitation and Hygiene: 2017 Update and SDG Baseline,” 2017. doi: 10.1016/j.pnpbp.2017.06.016.
- L. Strande and D. Brdjanovic, Faecal Sludge Management Systems. 2014. doi: 10.26530/oapen_578132.
- L. Strande, “Faecal Sludge Management – Systems Approach for Implementation and Operation,” Water Intell. Online, 2014, doi: 10.2166/9781780404738.
- A. Peal, B. Evans, I. Blackett, P. Hawkins, and C. Heymans, “A Review of Fecal Sludge Management in 12 Cities,” Water Sanit. Progr., no. June, p. 563, 2015.
- WHO., “Guidelines on sanitation and health.,” 2018.
- C. Troeger et al., “Estimates of global, regional, and national morbidity, mortality, and aetiologies of diarrhoeal diseases: a systematic analysis for the Global Burden of Disease Study 2015,” Lancet Infect. Dis., 2017, doi: 10.1016/S1473-3099(17)30276-1.
- WHO, “Investing to overcome the global impact of neglected tropical diseases: third WHO report on neglected diseases 2015.,” Invest. to overcome Glob. impact neglected Trop. Dis. third WHO Rep. neglected Dis., 2015.
- A. H. Hailu, K. Kibret, and H. Gebrekidan, “Characterization and classification of soils of Kabe Subwatershed in South Wollo Zone , Northeastern Ethiopia,” no. August, 2015.
- CSA & ICF, Central Statistical Agency (CSA) [Ethiopia] and ICF. 2016. Ethiopia Demographic and Health Survey 2016. Addis Ababa, Ethiopia, and Rockville, Maryland, USA: CSA and ICF. 2016.
- WHO, “CHERG-WHO Methods and Data Sources for Child Causes of Death 2000-2012. Global Health Estimates Technical Paper. WHO/HIS/HSI/GHE,” 2014.
- Kombolcha Town administration, “Annual magazine:Summerized reports of Health, education, demography and Housing.,” 2019.
- W. B. Abegaz and E. A. Abera, “Climatology & Weather Forecasting Temperature and Rainfall Trends in North Eastern Ethiopia,” pp. 1–6, 2020, doi: 10.35248/2332-2594.2020.8.262.
- SFD-PI, “Promotion Initiative. . SFD Manual (Version 2.0) (Vol. 1 and 2).,” 2017.
- C. Furlong, A. Mensah, J. Donkor, and R. . Scott, “Learnings from implementing the excreta flow diagram (SFD) process in Kumasi,” 39th WEDC Int. Conf. Ensuring availablility Sustain. Manag. water Sanit. all, no. Figure 1, pp. 1–6, 2016.
- G. D. Israel, “Determining Sample Size 1 The Level of Precision,” Univ. Florida, 1992.
- R. Scott, I. Ross, and I. Blackett, “Fecal Sludge Management: Diagnostics for Service Delivery in Urban Areas Case Study in Balikpapan, Indonesia,” 2016.
- WSP, “A Review of Fecal Sludge Management in 12 Cities, DRAFT for Internal Review. Prepared by Andy Peal and Barbara Evans. Washington, DC: World Bank Water and Sanitation Program (WSP) Urban Global Practice Team,” 2016.
- CSA, “The 2007 Population and Housing Census of Ethiopia,” 2007.
- Kombolcha town water supply and sewerage service authority, “Annual report,” 2019.
No competing interests reported.