Environmental Chicanery – Bangalore’s Sewage, Tamil Nadu’s Water

Bangalore TN Big Map

For a live Google Map, one that you can zoom in and journey the path of Bangalore’s sewage effluent’s travel through Tamil Nadu, see https://drive.google.com/open?id=1xUmQ-4eVglPGpKv50EntpdY6jSQ&usp=sharing

Google Maps has been a recent curiosity for me.  It’s lately turned into a minor obsession.  I can fly like an eagle, sitting on my computer and I can see the truth.  I don’t need the Government of India to tell me about the state of our rivers and its pollution.  I don’t need the media to give me an elevator pitch.  I want to see it with my own eyes.  You too can!

I’ll prove that all of our Bangalore sewage (shit, urine, soaps, household chemicals) is flushed into two major rivers, the Kaveri (Cauvery) and Thenpennai.  It travels through the whole width of Tamil Nadu, providing water for drinking and irrigation.  The people of Tamil Nadu have been hoodwinked by the Government of Karnataka.

Bangalore has a population of 12 million [1].  It is listed as the 18th most populous city in the world!  The Cauvery (Kaveri) river water project supplies 1350 MLD (million liters per day), which is augmented by water from other sources, including bore wells [3].  The BWSSB (Bangalore Water Supply and Sewerage Board) states that the personal consumption is 165 liters/day.  Based on this data, the people of Bangalore consume 1980 MLD.  This is also the amount of sewage discharge per day.

Let’s compute a few more things.  The average human feces, as per Britanica, is 100 to 250 grams/day [4].  A paper published in the National Institute of Health (US Department of Health and Human Services) lists the median fecal wet mass as 128 grams/day/person and urine at 1.42 liters/day [5].  Based on this data, I’ve estimated that Bangalore produces 1,536,000 Kg/day (1536 tones/day) of human feces (shit) and 17,040,000 Kg/day (17,040 tones/day) of urine.

We the people of Bangalore, just like others in the world, use soaps and shampoos for bathing, detergents for washing clothes and household chemicals (phenyls/phenols/acids/alkali/alcohols/ketones).  Let me go on the low side and consider that we consume a very small amount, say 10 grams/day.  This is 120,000 Kg/day (120 tones/day) of soaps, detergents and household chemicals.

In summary, the people of Bangalore are discharging 1980 MLD (1980,000,000 liters/day) of consumed water as waste, that is contaminated with 1,536,000 Kg/day (1536 tones/day) of human feces (shit), 17,040,000 Kg/day (17,040 tones/day) of urine and 120,000 Kg (120 tones/day) of soaps/detergents/household chemicals.  This is a total of about 2000 MLD (million liters per day) of sewage!

Just try to visualize it.  You have seen the large metal containers on trucks and on ships.  They are about 20 feet in length, 8 feet wide and 8.5 feet high.  In terms of trucks, the city discharges 52,105 trucks of sewage water, 40 trucks of shit, 448 trucks of urine and 3 trucks of soaps.  This is a total of 52,597 trucks of sewage!

The BWBSSB proudly lists on its web site that it has 14 STP’s (sewage treatment plants) in Bangalore, for a total processing capacity of 721 MLD.  The total sewage discharged is 2000 MLD.

This means 1279 MLD (1279,000,000 Kg) of sewage is discharged untreated.  The actual amount is more, since the Bangalore STP’s have been documented to be dysfunctional and not operating to rated capacities.  For simplicity, I will take the untreated sewage to discharge 1300 MLD.

This is a massive amount to let out and this is a real environmental disaster.  The real sad part is that it is let out into two major rivers, the Thenpennai and Kaveri, that traverse through the heart of the State of Tamil Nadu.

The right half of Bangalore (see the interactive Google Map, mustard circles) lets out approximately half the sewage, which is 1000 MLD and which contains about 650 MLD of untreated sewage.  This stream first collects in the Bellandur Lake and overflows into the Varthur Lake.  From here, it meanders south for about 40 Km to Kelavarapelli Reservoir.  The outflow from here is designated as the “Then Pennai River”, which is also known as the “Ponnaiyar River”.  It then flows to the Krishnagiri Dam, further south, which is about 60 Km from the Keleavarapelli Reservoir.  It journey’s on for another 106 Km south-east to the Sathanur Reservoir, in the heart of Tamil Nadu.  It then follows the south-easterly gradient for another 116 Km and drains into the Bay of Bengal at Cuddalore, in Tamil Nadu.  This part of the sewage from Bangalore thus traverses a path of about 322 Km.

The left half of Bangalore (see the interactive Google Map, purple circles) again discharges about 1000 MLD of sewage and 650 MLD of untreated sewage.  The birth place is near the Sankey Tank in Bangalore, which is in the uber-rich part of the city and the stream gets the privilege of being called the “Vrishabhavathi River.”  It travels south-west, along parts of the Bangalore-Mysore highway, for 34 Km and flows into the Vrishabhavathi Reservoir.  When you exit Bangalore, en route to Mysore, you get a nasty stench from this river.   It’s common knowledge that this is because of untreated sewage water.  It continues from the Reservoir and travels 19 Km and joins the Arkavathi River (orange circles).  From this point, it travers another 41 Km southwards and meets the great Kaveri (Cauvery) River, near the Mugguru Forest and Mekedatu.  It journeys on, in a south-westerly direction, into Tamil Nadu and flows into the Stanley Reservoir (Mettur Dam).  From here, the Kaveri River travels a long distance of about 220 Km and forks off at Tiruchirapalli.  One stream splits to the top as the Kollidam River and drains into the Bay of Bengal at Chidambaram, after traveling 104 Km.  The other splits to the bottom, still as the famed Kaveri River, and travels about 107 Km and ends in the Bay of Bengal at Kaveripattanam.  This part of the Bangalore sewage traverses about 421 Km.

I really hope that the above details will help you zoom into the Google Map and traverse the wondrous paths of the Bangalore sewage.

This is a national disaster.  I just hope the people of Tamil Nadu can forgive the negligence of the city of Bangalore and the State of Karnataka.  It is irresponsible for the State of Karnataka to discharge its sewage water, with no regard to the welfare of the people of India.

What will happen now?  Should the State of Tamil Nadu sue the State of Karnataka and the city of Bangalore in the National Green Tribunal (NGT)?  Will the NGT, without application of mind, ask the people of Bangalore to stop defecating (shit, urine), stop taking bath (soaps), stop washing clothes (detergents) and stop cleaning their homes (household chemicals)?  Should the people of Bangalore stop living?

My answer is a resounding NO!  We need to solve this environmental catastrophe.  The simple solution is to ensure that every drop of sewage is treated in STP’s using the latest technology, before discharging it.  I have computed earlier that Bangalore has an immediate need for additional STP’s to process 1300 MLD of untreated sewage waste.  These types of problems have been solved, both in India and in other countries.  The technology is well known and well proven.  What is needed is the will of the Government of Karnataka to be honest and do the right thing.  They should stop using shoddy third rate stupid science and use its power to provide the best solutions for a stable and sustainable environment.

I can’t help but think of Uncle Ben telling Spiderman – “With great power comes great responsibility!”


[1] Population of Bangalore – http://indiapopulation2017.in/population-of-bengaluru-2017.html

[2] http://worldpopulationreview.com/world-cities/bangalore-population/

[3] BWSSB – https://bwssb.gov.in/content/about-bwssb-2

[4] Britanica feces – https://www.britannica.com/science/feces

[5] NIH feces paper – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4500995/


For a visual journey of this article please see my next post:



3 thoughts on “Environmental Chicanery – Bangalore’s Sewage, Tamil Nadu’s Water

  1. Dear Prakash,
    A brilliant structured case for the authorities to take cognizance and action immediately. I shudder to think what the environmental engineers working in these government agencies are actually doing. “Scratching their crotches” as we say in Kannada..!


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