Infrastructure investments and operating costs for fecal sludge and sewage treatment systems in Kampala, Uganda

Figures & data

Figure 1. Maps of the study area: left-hand map shows the location of Kampala, Uganda in Africa (Google) and right-hand map shows the districts within Greater Kampala Metropolitan area, including demarcation of population levels and type of sanitation system. The central Division of Kampala is largely sewered (striped area), while parts of Rubaga, Makindye, Nakawa, and Kawempe Divisions are sewered although a majority still use on-site systems (dotted areas). The remaining areas are served by septic tanks and pit latrines, with a strong predominance for pit latrines. Data source: Uganda Bureau of Statistics (http://ubos.geo-solutions.it). Accessed 2019-09-10.

Figure 2. Simplified fecal flow diagram for the Greater Kampala region, based on data from Kampala Sanitation Master Plan (2015), and assessments made by Schoebitz, Niwagaba, and Strande (2016) and Niwagaba (n.d.).

Table 1. Annualized capital and operating costs for the centralized and on-site sanitation regimes in Greater Kampala, Uganda. Costs are broken down by stakeholder and service along the service chain.*

		Sewage Regime				Fecal Sludge Regime
		Household	NWSC	End-user	Total	Household	C&T company	NWSC	End-user	Total
Annualized Capital Costs (USD/pe*yr)
Household connection – capital	Household connection^a	−11.51	0.00	0.00		−12.17	0.00	0.00	0.00
Collection & conveyance – capital	Collection & conveyance^b	0.00	−154.45	0.00		0.00	−0.12	0.00	0.00
Treatment plant – capital	Treatment plant^c	0.00	−138.10	0.00		0.00	0.00	−0.66	0.00
Total	Total	−11.51	−292.55	0.00	−304.06	−12.17	−0.12	−0.66	0.00	−12.95
Annual Operating Costs (USD/pe*yr)
Collection & conveyance – operating	Collection & conveyance^d	0.00	0.00	0.00	0.00	−0.88	0.34	0.00	0.00	−0.55
Sanitation fee	Sanitation fee^e	−14.40	205.98	0.00	191.58	0.00	−0.11	0.11	0.00	0.00
Treatment plant – operating	Treatment plant^f	0.00	−73.64	0.00	−73.64	0.00	0.00	−0.19	0.00	−0.19
Valorization of end-products	Valorization of end-products^g	0.00	0.02	−0.02	0.00	0.00	0.00	0.01	−0.01	0.00
Total	Total	−14.40	132.35	−0.02	117.93	−0.88	0.23	−0.06	−0.01	−0.73
Total Annual Capital and Operating costs (USD per capita/year)		−25.91	−160.20	−0.02	−186.13	−13.05	0.11	−0.72	−0.01	−13.68

*Brief explanations are provided, and further details can be found in the Supporting Information (SI).

^aHousehold connection (capital) = household sewer connection & bathroom or on-site sanitation system (weighted average of three types of systems, latrines or septic tank), including superstructure.

^bCollection & conveyance (capital) = sewers and pumping stations or vacuum trucks.

^cTreatment plant (capital) = construction costs for wastewater or fecal sludge treatment plants.

^dCollection & conveyance (operating) = truck transportation and maintenance. NB: centralized regime operating costs for collection & conveyance are included in treatment O&M costs.

^eSanitation fee = sanitation tax paid for sewerage service or emptying fee paid for service of on-site systems.

^fTreatment plant (operating) = O&M costs for wastewater or fecal sludge treatment plant.

^gValorization of end-products (operating) = sale of sludge.

Table 2. Comparison of costs and households’ share of costs for the sewage and fecal sludge (FS) regimes, presented as the ratios of costs between regimes and percentage of costs paid by households (derived from values shown in Table 1).

	Sewage regime (USD cap.^−1 yr^−1)	FS regime (USD cap.^−1 yr^−1)	Sewage regime:FS regime cost ratio	% of costs paid by households in the sewage regime	% of costs paid by households in the FS regime
Total annualized capital costs	304	13	23	4%	94%
Total annualized operating costs, excluding revenues	74	0.73	101	20%	121%
Combined annualized capital and operating costs, including revenues	186	14	13	14%	95%

Figure 3. Annualized capital and operating costs for the (left) centralized sewage regime and (right) on-site fecal sludge regime in Greater Kampala, Uganda. Note that some cost items are too small to be shown in the diagram (see Table 1 for exact values).

Figure 4. Changes in total annualized capital and operating costs in the sewage regime based on increasing the number of people connected to the system to the maximum capacity of existing wastewater treatment plants (WWTPs), while keeping the ratio of domestic to non-domestic customers the same (i.e. 16% domestic).

Figure 5. Financial flows between stakeholders in the (top) centralized sewage regime and (bottom) on-site fecal sludge regime. The size of the arrows is proportionate to the financial flow in question. The dashed lines represent stakeholders not included in this study.

Schoebitz, L., C. Niwagaba, and L. Strande. 2016. SFD Promotion Initiative – Kampala, Uganda. Kampala, Uganda. https://www.susana.org/_resources/documents/default/3-2593-7-1478269444.pdf

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Niwagaba, C. B. n.d. Shit Flow Diagram (SFD) for Kampala City. Draft Report Prepared as Part of the Deliverables for AfWA on the Project Reinforcing African Sanitation Operators Partnerships (RASOP), under Review. Abidjan, Côte d'Ivoire: African Water Association.

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