The 4S Project

The 4S Project: Evidence-Based Recommendations for Small-Scale Wastewater Treatment and Reuse Systems in India

By Christoph Lüthi and Lukas Ulrich

Wastewater sampling at a treatment plant in Tamil Nadu (Photo: IIT Madras).

The project Small-Scale Sanitation Scaling-Up (4S), funded by the Gates Foundation, was the first systematic assessment of small-scale sanitation (SSS) systems in South Asia. It aimed to provide policy recommendations for the successful implementation and operation of SSS systems at scale. India was the focus country, with more than 20’000 privately owned and operated units already installed. The three-year research was implemented by Eawag-Sandec in collaboration with IIT Madras, BORDA and other partners.

The study included the following main components:

  • Technology, implementation and operation: landscape study, basic assessment of more than 300 existing systems, and detailed performance analysis of 40 systems
  • Governance: analysis of policies, regulations, stakeholders and institutional arrangements for SSS
  • Financial sustainability: study of life cycle costs of systems as well as financial reasons for underperforming systems

The researchers analysed the factors critical for the success of SSS systems (see diagram), which is also a key research focus of Wings. Research methods included site inspection, wastewater sampling and stakeholder interviews.

Some of the key findings are:

  • Current policies in India have enabled the establishment of a capable private sector with technical solutions ready to be scaled up. In Bangalore, an estimated 10-20% of the wastewater is already treated and partly reused by SSS systems.
  • Any of the technologies studied have the potential to achieve quite stringent BOD, COD and TSS standards. However, systems generally fail to meet nutrient and microbial parameters.
  • Poor performance is commonly linked to unclear responsibilities, insufficient instruction and supervision of operators and intermittent operation, among other reasons.
  • The rapid scaling-up of SSS in India has not been accompanied by the development of the necessary governance framework. As a consequence, SSS systems often suffer from a lack of proper management, insufficient monitoring and weak enforcement.
  • Life cycle costs vary considerably between technologies, but choices are often made based on capital costs only, leading to high running costs.

Two resulting key recommendations are i) the creation of dedicated SSS management units at state and city level, and ii) the development of an online platform collating all databases, streamlining processes from establishment to monitoring, and allowing meaningful collaboration between stakeholders.

Key insights

  • Having been a relatively unmanaged process until now, it is evident that there are major challenges to the on-going scale-up of small-scale sanitation systems in India.
  • Taking control of the process and implementing targeted measures both at the sanitation system level and at the governance level can lead to tremendous benefits in terms of public health, environmental protection and water reuse.

Contact

Dr. Christoph Lüthi Dr. Eng. Infrastructure Planning Tel. +41 58 765 5614 Send Mail

Key publications

Technology, implementation and operation of small‐scale sanitation in India. Performance analysis and policy recommendations. Small‐scale sanitation scaling‐up (4S) - project report vol. I

Introduction – In addition to underground drainage and large‐scale sewage treatment plants (STPs) and the management of faecal sludge and septage from non‐sewered on‐site systems, small‐scale sanitation (SSS) systems are becoming increasingly important. Such systems consist of small‐scale sewerage networks and STPs, allowing for incremental, modular and flexible implementation. Therefore, they have significant potential for cost‐effective local wastewater treatment and reuse. In order to improve public health, relieve water stress and protect the environment in urban India, SSS systems have a key role to play.
Since a policy drive for small sewage treatment plants (SSTPs) in India beginning in 2006, there has been a remarkable growth in the number of installations in the country’s rapidly expanding urban areas, especially in big cities. However, it is known that many of the existing systems are underperforming or have failed for various reasons.
Thus far, SSS sector developments in India have not been informed by a systematic assessment of lessons learned, and there has been very little research on the enabling conditions and implications for the successful long‐term operation and management of SSS systems at scale. The main goal of the "Technology, Implementation and Operation" component of the 4S Project is to evaluate present experience with SSS systems and to develop evidence‐based policy recommendations for their successful design, implementation, operation and maintenance at scale.
Klinger, M.; Ulrich, L.; Ramprasad, C.; Wolf, A. T.; Reynaud, N.; Narayan, A. S.; Siemsen, P.; Lüthi, C.; Philip, L. (2020) Technology, implementation and operation of small‐scale sanitation in India. Performance analysis and policy recommendations. Small‐scale sanitation scaling‐up (4S) - project report vol. I, 127 p, Institutional Repository

Governance arrangements for the scaling up of small-scale wastewater treatment and reuse systems - lessons from India

Environmental pollution and increasing water scarcity are key features of the urban landscape of India today. The extension of centralized sewerage networks cannot keep up with city growth, and alternative sanitation systems are needed for citywide inclusive sanitation (CWIS). The government of India mandated larger buildings to be equipped with small-scale wastewater treatment plants (SSTP). This resulted in the emergence of a large number of technology and service providers, and in the implementation of thousands of private SSTPs. However, this quick scaling up was not accompanied by the development of appropriate governance arrangements. As a result, a significant proportion of SSTPs underperform and do not meet the effluent standards. Through a systematic analysis of governance arrangements around SSTPs, this contribution analyses the scaling up process of small-scale wastewater management and reuse at building level in India, in particular in the state of Karnataka and the city of Bengaluru. This paper identifies the gaps in this multi-level, polycentric governance framework and investigates which arrangements are needed to enable the performance of SSTPs on the ground and to create the necessary synergies between the relevant governmental agencies, the private sector and civil society. The scaling up of SSTPs in India mainly followed a market governance approach within a governance environment that is traditionally very hierarchical. The authors argue that hybrid governance arrangements, blending hierarchical, market and network governance are needed to foster market regulation and stakeholder coordination, and increase the performance of the sector. They conclude that an efficient governance of SSS requires the creation of dedicated SSS units at state and city level, and the development of an online platform collating all databases, streamlining and supporting processes from establishment to monitoring, and allowing meaningful collaboration between stakeholders. Through the case study of India, this paper contributes to understand the governance arrangements necessary for the successful scaling up of decentralized sanitation systems, and how to fulfill the potential of alternative solutions for sustainable urban water management. It contributes to governance studies by substantiating the concept of hybrid governance approach and proposing concrete measures to make it work for such distributed systems.
Reymond, P.; Chandragiri, R.; Ulrich, L. (2020) Governance arrangements for the scaling up of small-scale wastewater treatment and reuse systems - lessons from India, Frontiers in Environmental Science, 8, 72 (16 pp.), doi:10.3389/fenvs.2020.00072, Institutional Repository

Project Website

4S is assessing small-scale sanitation systems in South Asia to provide policy recommendations for improved sanitation system design, implementation and O&M.

4S: Small-Scale Sanitation Scaling-Up