Swachh Bharat Mission 2: Why centralised sanitation will not address urban problems

SBM 2 introduces a one STP nalla-based waste water treatment system, without a town sewerage system for small and medium towns as another option 

By Depinder Kapur
Published: Monday 21 June 2021

India achieved ‘open-defecation-free’ status in 2019 under the Union government’s Swachh Bharat Mission (SBM); the second phase of the SBM is expected to address the problem of waste water treatment from the perspective of diversity of Indian towns representing a range of topographic, climatic and demography variations.

The crisis of urban sanitation in India is manifested by the predominant septic tanks-based sanitation systems that far exceed the coverage of households provided by centralised sewerage-based systems.

The SBM 2.0 has not been announced yet. It seems, from the informal news and information available as of now, that it has announced a one sewage treatment plant (STP) nullah-based waste water treatment system, without a town sewerage system for small- and medium-sized towns as another option. This would specifically reject sullage and septage treatment through independent decentralised faecal sludge treatment plants.

We hope this would not be the final version of SBM 2.0. If adopted, this approach may become the de-facto urban sanitation policy for India, which may reject the progress made in the last five years on promoting decentralised and networked sanitation systems as complimentary systems to the exclusive centralised sanitation systems.

This paper is an advocacy attempt in that direction.

A one STP per town, nullah-based treatment approach is not likely to address the problems Indian towns. There are several reasons behind this skepticism:

  • About two-thirds of India is semi-arid and arid. Small and medium towns having less than 100,000 people in these regions — that extend from large tracts of north west to central and southern India — will never generate sufficient waste water flows in nullahs that can be tapped and treated by STPs.
  • The minimum waste water strength (measured in terms of minimum biological oxygen demand) in places where rainfall is high or ground water is good — such as basin and eastern Indian states — may not be there and STPs will not work.

This approach risks the outcome of creating a massive dead capital expenditure (CAPEX) investments in nullah-based STP infrastructure. Land application of faecal sludge suggested as an option for septage treatment with no prior treatment may work in some instances (for example, non-food crops cultivation), but cannot be recommended as a solution for septage management urban sanitation under a national mission.

Centralised networked sanitation systems 

The imperative of addressing urban waste water and sanitation in India needs no introduction. The state of our contaminated ground water, surface water and water bodies and the ever increasing thirst of our towns and cities for clean water is a testimony to this.

We may run out of clean water, unless there is a concerted effort and a governance mandate to reduce the waste water footprint. The NITI Aayog raised an alarm in 2018 for Indian cities regarding this.

Centralised networked sanitation systems have been the standard recommended approach for addressing urban waste water management. Not even a single Indian city, however, has a 100 per cent sewerage-based system.

Intermediate solutions for the treatment of nullah waste water — using an STP through interceptor sewers — has been proposed for large metros and towns.

In the early days of the National Mission for Clean Ganga (NMCG), when engineers were invited to share their solutions for the mission, one engineer suggested to “construct a parallel interceptor waste water channel next to the river Ganga”. This channel, according to the engineer, a man-made large drain, will collect all the waste water flowing from the Ganga towns and take it for treatment to a location a few 100 kilometres away.

The suggestion was to have a series of such plants, which would help avoid getting into the difficult business of setting up several treatment plants for each town along Ganga.

Funny as it may look, this suggestion was offered as an innovative option for urban waste water treatment. Till someone pointed out that one would have needed to build a parallel Ganga river canal with the same, if not larger width, to carry all the waste water generated.  

This example is given as a contra factual to what is under active consideration today in SBM 2.0 guidelines as a solution for urban waste water management in India: A one-town, one-sewage treatment plant (based on nullah tapping, without a sewerage system) approach as the urban waste water management solution for small and medium towns in India.

Current status and priorities

What is the urban waste water management policy / priority for urban India?

The Central Public Health and Engineering Organization of India Urban Sanitation Manual of 2013, in its preamble, highlights the challenges of implementation of centralised waste water management solutions borrowed from post-World War II western world.

It categorically questions the blind adoption of centralised waste water and management systems and their applicability for India.

CPHEEO manual, Part A, Preamble, Page 1-2, say:

“It is also necessary to recognise that the practice of piped sewer collection is an inheritance from advanced countries with high water usages, which permit adequate slushing velocities. Due to their high per capita water supply rates, the night-soil does not settle in pipes and hence no choking and no sulphide gas generation. Whereas, in the Indian scenario, the per capita water supply is low and inequitable in many cities and that too intermittent and this results in settling down of night-soil in the sewers, choking, gasification, etc., which necessitates very often extreme remedies of cutting open roads to access and break open the pipes for rectification and so on.”

The National Urban Sanitation Policy, 2008, had rightly identified the need for state sanitation strategies and city sanitation planning as key instruments to address the urban sanitation and waste water management challenge.

Each state was expected to come up with a long-terms vision, strategy and action plan including funding requirement for their urban sanitation and waste water management. This is yet to materialise in any meaningful manner.

States like Odisha, Andhra Pradesh, Tamil Nadu, Maharashtra and Telengana in the last five years have come out with their state-specific urban sanitation priorities that have identified non-networked sanitation systems and septage management as a priority.

SBM 2.0: The considerations

Out of the 7,935 towns, according to the 2011 census (4,041 statutory towns with their urban governance infrastructure and another 3,894 census towns without this), only 465 towns had a population above 100,000. These numbers will increase in 2021.

The 2021 Swachh Bharat Mission 2.0, which is now in its draft final stage, has rightly prioritised waste water management in small and medium towns. However, what is proposed has not been put out for public consultation or feedback.

It is feared that the SBM 2.0 may prioritise nullah-based STP as a short cut solution to the crisis of urban waste water management, without town-level sewerage systems. Land application of faecal sludge from septic tanks give rise to similar concerns.

Both the options may not address the urban sanitation challenge of Indian towns. Land application of faecal sludge without any treatment may lead to spreading of faecal contamination into crops and food system if not regulated for non-food crops only.

And a creation of nullah-based STPs may end up as a massive dead infrastructure investment.

Massive investments have been made in centralised sanitation systems development for Indian cities in the last five decades. However, these have been very expensive to build, operate and maintain.

Often resulting in the STP infrastructure being unutilised or underutilised for reasons of failure of operation and maintenance (O&M) contracts leading to non-operation of STPs, and the general apathy towards O&M works while more and more funding is allocated for new sanitation infrastructure CAPEX works.

Decentralised, small STPs and non-sewered sanitation systems for large towns have been initiated in the last five years and by states such as Odisha fully adopting non-sewer sanitation systems as solutions for urban sanitation.

In terms of today’s cost, centralised sewage treatment systems (consisting of underground network of sewerage pipes linked to an STP) will cost between Rs 15,000 and Rs 25,000 per capita, as is evident from the budgeting of water supply under Jal Jivan Mission.

The Jal Jivan Mission (2019) has comparable range of per capita cost for providing piped drinking water supply for single village schemes and a much higher figure for multi village piped water schemes.

For a small town of say 50,000 people, the CAPEX investment for centralised sewage systems will be at least Rs 100 crore per town (assuming an average of Rs 20,000 per capita investment). The annual O&M costs will be in addition to this, and would be usually higher in account of electricity and pumping charges.

Only a few of the 7,500 small and medium towns in India (2011 census) can afford to invest Rs 100 crore for a sewerage-based sanitation system, given that currently most towns of India are depend on the Central Finance Commission to recover 30-80 per cent of their annual operational budgets.

Therefore, not a single large or small town in India has 100 per cent networked sewage system connectivity so far.

Sewerage based STPs for 7,500 towns will require a massive Rs 750,000 crore investment at today’s price.

SBM 1.0 had an allocation of Rs 18,000 crore over a five-year-long period from 2015 to 2020. Funding requirement for all small and medium towns will, therefore, take at least 40 to 50 years to materialise.

This is part one of the three-part series on urban sanition policy under Swachh Bharat Mission 2

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