Pit latrines are the most common household sanitation system in cities in Sub-Saharan Africa (1) particularly in informal settlements. (2) As cities become more densely populated, there is often no space to replace latrines when they are full. To protect public and environmental health, pits must be emptied and the sludge safely transported to an appropriate disposal or treatment site. (3) Growing urban populations and the improved access to household sanitations means that the amount of sludge requiring emptying is fast increasing. (4)

In many cities private sector service providers empty septic tanks and pit latrines using exhauster trucks, but exhauster trucks may be unable to access pits in dense settlements without roads, handle trash and to remove thick sludge. (5−7) Manual emptying (using either a manually operated pump such as the Gulper, or buckets and rope) (8) is therefore required, and is typically done informally and the sludge not safely disposed. (9) In response, several cities have formalized manual emptying service providers. Licenses from the relevant authorities (10) generally require the adoption of more hygienic technologies (such as the Gulper (11,12)) and the transport of sludge in barrels to a treatment or a safe disposal site. Formalisation incurs additional safety, licensing, and transportation costs; (13) manual emptying is slower; (14) and some systems cannot be emptied using methods accepted by licensing authorities. (5,7) Furthermore, the benefits are not private and it does not substantially increase willingness to pay, which increases the large funding gap. (15,16) Households paying for emptying services prefer to reduce individual payments to help manage budgets. (9) Service providers have responded by offering volumetric tariffs and removing smaller sludge volumes. (7,10,17) As sanitation is a public good, (18) market-based systems will not provide universal services without additional incentives (19) and since sanitation is also a merit good, (18) cities are increasingly revisiting how to increase coverage of formal services by adopting a public service approach. (20)

City authorities need more cost data and analysis to inform financial planning (21) to support both private sector participation and public service delivery e.g., cost underestimation has caused challenges for subsidy design. (22) Previous peer reviewed studies have found that costs could be lowered by clustering jobs at the neighborhood level, (23,24) the additional costs of formalization are significant, (13) and operating systems below design capacity increases average costs. (25) But these studies analyzed individual formal manual emptying service providers, not allowing for cross-comparison to improve the reliability and generalizability of findings.

In this study we analyze empirical operational and financial data from a household and a service provider survey in Blantyre, Malawi and Kampala, Uganda produced by Water For People (an international non-governmental organization headquartered in the USA). Data was produced from service providers who have previously received support from Water For People, either directly or indirectly through market-system development. (26) A whole-life cost accounting methodology developed specifically for urban sanitation and city authorities (8) is used to organize cost data to understand service providers’ unit costs and cost structures, and to calculate the Total Annualized Cost per Household (TACH). TACH was developed and is used in this study because it represents the full financial cost of delivering a component of the sanitation service chain (emptying and transport in this study) and is expressed in a unit (annualized cost per household) that is most useful to city authorities by aligning with annual budgeting, enabling comparison to other public services.