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Insights into Editorial: De-odourising sewage

Insights into Editorial: De-odourising sewage

Introduction: Present status of Water Pollution:

we all know water is crucial for life, we trash it anyway. Some 80 percent of the world’s wastewater is dumped largely untreated back into the environment, polluting rivers, lakes, and oceans.

This widespread problem of water pollution is jeopardizing our health.

  • Unsafe water kills more people each year than war and all other forms of violence combined.


  • Meanwhile, our drinkable water sources are finite: Less than 1 percent of the earth’s freshwater is actually accessible to us.


  • Without action, the challenges will only increase by 2050, when global demand for freshwater is expected to be one-third greater than it is now.


  • The World Bank estimates that more than a fifth of all communicable diseases in India (21%) are caused by contaminated water.
  • It attributes one in ten deaths in India to diseases or infections directly or indirectly transmitted through water.


  • Over 500 children die every day in India due to diarrhoeal diseases. Water pollution occurs when harmful substances often chemicals or microorganisms contaminate a stream, river, lake, ocean, aquifer, or other body of water, degrading water quality and rendering it toxic to humans or the environment.


Accessing water in Future implies Careful Usage of water in Present:

According to NITI Aayog’s composite water management index report released last year, 75% of households do not have access to drinking water on premises, 70% households lack piped water (potable or otherwise) and as many as 20 cities will effectively use up all available water resources by 2020.

Sewage and waste need to come centre stage in our policy debates.


Water Pollution: Reactive Nitrogen, a growing pollutant:

According to a study by the Indian Nitrogen Group, a task force of scientists tracking the issue, the amount of reactive nitrogen in a bulk of the water bodies in India is already twice the limit prescribed by WHO.

Nitrogen pollution from untreated sewage, the study found, now outstrips nitrogen pollution from the Indian farmer’s urea addiction. Now, add nitrogen pollution to the list.

The centre and state Government efforts has managed to make toilets top of the mind in our country, with its Swachh Bharat Abhiyan.

Toilets are being built in mission mode and there is enough anecdotal evidence to suggest that there has been a measurable reduction in the number of people defecating in the open, which stood at over 500 million or half the population a few years ago.


How is India’s nitrogen pollution different from that of the world?

  • Nitrogen pollution differs from country to country, depending on the sources of contribution, which can be anything from agriculture, domestic and municipal sewage to fossil fuel burning, vehicles, industries and residue burning.


  • The biggest human-made source of nitrogen pollution is unused fertiliser in the farms, whether chemical or biological in origin.


  • In India, due to the unaffordability of precision agriculture or labour costs for frequent application of fertilisers in small doses, farmers apply fertilisers in fewer but larger doses.


  • But since crops cannot use the fertilisers fully, they contribute to the reactive nitrogen pollution in India.
  • Most of it comes from cereal cultivation, whereas in other countries, it may come mainly from horticultural crops or cash crops as in China, or even from forage crops and livestock or animal farming as in Europe.


  • Africa has a negative balance of nitrogen, which means due to lack of sufficient fertiliser/manure, farmers in the continent are mining away whatever little nitrogen is left in the soil, causing soil degradation.


Clean India Missions- but scarcity of Waste and Sewage Treatment Missions:

  • India’s latest, largest and most significantly scaled attempt at cleanliness the Swachh Bharat Abhiyan is likely to add to this problem.


  • Under the mission, over nine crore toilets have been constructed. Of these, only 60 lakh are in urban areas, where one assumes they are connected to some sort of sewage system (even this assumption is a stretch.



  • A study done by the Centre for Science and Environment in 30 cities in Uttar Pradesh found that only 28% of toilets in these cities were connected to a sewage system). The rest will be generating fecal sludge, sewage and septage which has no place to go.


  • Which means that that too will simply get dumped, polluting land, surface and ground water and killing our rivers and ponds.


  • According to the Central Pollution Control Board (CPCB), 63% of urban sewage flowing into rivers is untreated.
  • All this, one would have presumed, prodded policymakers and governments into action.


  • Just like the nation is building toilets in mission mode, one would have thought civic administrations would be building drains and sewers and treatment plants with the same zeal.


  • Of the 99 cities in the ‘Smart Cities’ mission, which are collectively spending 2 lakh crore over five years (from 2015), only 2.4% of the money is going to be spent on waste management.


  • Other schemes like the Atal Mission for Rejuvenation and Urban Transformation (AMRUT) also fund such schemes. AMRUT covers a much larger spread 500 so-called ‘mission cities’ across the country. Of these, only 217 pitched for a sewage treatment plant as an AMRUT project.


Way Forward:

Can we maintain a balance between the use of fertilisers to achieve food security and limiting nitrogen pollution?

Yes. Firstly, India’s food grain production is not growing at par with the increase in fertiliser consumption. In fact, the role of nitrogen in cereal production has fallen sharply in the last two decades.

Continuous increase in fertiliser usage without addressing the limiting factors will only result in diminishing returns in terms of yield, besides imposing environmental costs.

We need to rationalise the unbalanced usage of nitrogen fertilisers in irrigated areas that grow multiple crops in a year and ensure need-based usage of nitrogen fertilisers in all areas, even if it means a slight increase in its usage in rain-fed areas.

But most importantly, we need to put the clamps on non-agricultural sources of nitrogen, which are spewing the pollution at a much faster rate.



we have all the scientific capacity needed to assess our reactive nitrogen loads, sources, sinks, flows and future scenarios, as well as identify possible interventions.

Reducing the use of nitrogen fertilisers and increasing that of recycled manures offers the prospect for Indian farmers to produce food more securely and profitably, while saving the government a huge amount of money.

Elections may be fought on ‘bijli, sadak, paani’ (power, roads, water) but no election is fought over naali (drain). Unless that happens, we run the real risk of eventually either choking or being poisoned by our own waste.

If only we leverage this scientific and environmental soft power to tweak our environmental diplomacy with the changing times, geopolitics and economics, we can easily demonstrate our potential for global environmental leadership.