**2. Unearthing facts of On-Site Systems (OSS) in urban India**

The global sanitation agenda has mainstreamed the importance of on-site systems and FSM in achieving safely managed sanitation in urban and rural areas alike in the Global South. The newfound recognition of non-networked sanitation as a viable and necessary alternative to sewerage systems led the Ministry of Housing and Urban Affairs (MoHUA), Government of India, to issue the National Policy on Faecal Sludge and Septage Management, 2017. The Policy has created an imperative at the national level for the implementation of FSM and set out the necessary priorities and directions for the states. It introduces the sanitation service chain as a framework for understanding the issues of non-networked sanitation, and while it does go over the importance of ensuring that on-site systems are compliant, no governmental programme for their improvement has stemmed from it so far.

Without detailed data on the exact nature of deviations and what requirements households are trying to solve for in adopting certain preferences in design, a responsive and comprehensive strategy for improving the quality of on-site systems cannot emerge. The general view of non-compliance of on-site systems derives directly from the poor application of building regulations overall in Indian cities [8]. Building regulations despite their stringent provisions for enforcement are violated in India due to low awareness of households regarding their importance, a laggard upgradation of rules and systems when compared to the ever-evolving

*Managing Non-Sewered Sanitation for Achieving Sustainable Development Goal 6 in India DOI: http://dx.doi.org/10.5772/intechopen.98597*

ground realities, and perhaps most critically, the weak capacity of local authorities in enforcing the regulations.

The National Sample Survey 76th Round (administered by the Ministry of Statistics and Programme Implementation), 2018, asked households how often they desludge their on-site systems and for related details viz. service provider, place of disposal, service charges. It was the first time that recurring nation data collection efforts had articulated such questions, with the Census of India and the preceding rounds of the National Sample Survey only asking about which type of on-site system the toilet has. Still, the framing of these questions is rooted more in understanding the need for FSM than in defining the attributes of on-site systems in and of themselves. As the following sections will show, the timely desludging of faecal sludge and septage from these systems and its safe management downstream is critical, but it is a recurring event that does not inherently fix all the issues in the system's day-to-day and year-round performance.

To plug the gap in the data available on on-site systems and the agenda for their improvement, the authors' conducted a novel multi-state survey of 3,000 households across urban India. The survey focused its attention on cities and towns with a population of less than 1,000,000, given that these are the ones that, given the trajectory of sewerage system development, would continue to depend on nonnetworked sanitation in the medium to long term. Since typically hydrogeological factors such as the depth to the groundwater table, terrain, and soil type are contributing factors in determining the most suitable design of an on-site system, the 3,000 households were spread out over the four hydrogeologically diverse states of Madhya Pradesh (plains, moderate water table), Rajasthan (desert soils, low water table) Odisha (coastal, high water table), and Uttarakhand (hilly, moderate to low water table). The sampling design ultimately selected a total of ten cities in these four states as sites of enquiry. Structured interviews with masons, public health engineers/sanitation inspectors, and desludging service providers accompanied the household survey to allow for the triangulation and better contextualisation of the survey findings [9].

The following sub-sections discuss the main findings of the survey and their implications.

#### **2.1 Higher dependence on septic tanks compared to leaching pits**

As seen earlier, the need for the invention of the septic tank system was rooted in a desire for improving the cesspits, cesspools, and privies prevalent during the latter half of the nineteenth century. The leaching of contaminants to the subsurface in the high-density areas typical of burgeoning cities and a limited network of piped water supply combine to create disease outbreaks like the Broad Street Cholera Outbreak of 1854 in London [10]. While the unimproved systems of the time were eschewed for sewerage systems and septic tank systems in the Global North the discourse in the Global South stayed stagnated on (a) sewerage systems as the sanitation standard to aspire to and (b) twin pits as the government's preferred low-cost technological options in its absence, the latter as recently as the ongoing SBM Phase II.

Nonetheless, the data notes that nine out of ten toilet-owning households in these cities depend on a septic tank. It is important to note at this juncture that the authors' use of the phrase 'septic tank' is intentional since the majority of households construct the septic tank system only partially, i.e. construct the septic tank, which serves as the primary treatment unit, without constructing second component for secondary treatment or safe disposal of the tank effluent. The clear preference for septic tanks in urban areas is evinced by the fact that leaching pits are significantly associated (p < 0.01) with a lower standard of living, a lower monthly per capita expenditure, semi-permanent or temporary housing, and smaller plot sizes on average. In other words, between septic tanks and leaching pits, urban households view the former as the better option, and the construction of the latter is more a function of capital constraints than an informed preference. Another way the phenomenon manifests is when the prevalence of the two main types of on-site systems is disaggregated by whether the households constructed the toilet on their own ('privately constructed') or under a government programme ('subsidy led'). The share of leaching pits rises a little over three times among toilets constructed under the government programme (**Figure 2**).

The de facto and widespread preference for septic tanks, emerging without a governmental boost, already means that urban India is at an intermediate point in the trajectory towards mature ecosystems for non-networked sanitation. The relatively low prevalence of leaching pits at the city level may have staved off acute incidences of waterborne diseases, but as the following sections show, more ground needs covering before Indian cities have well-functioning sanitation service chains from the toilet to treatment.
