A living superorganism amongst us – Reimagining Wastewater Treatment Plants
The world we live in always has a liking towards fantasy. We have always attributed unexplained phenomenon through rich imagery and that led to flourishing of tales and folklore within our culture. Atheists may call religion as a result of vivid imagination too. Imagination and intuition has always led us, the mankind to unravel deeper secrets of the universe like Gravity.
If someone claims that City is a living being, how many of us would believe it. Many would out rightly reject such an idea and call it bizarre while some may philosophically attribute city to a body less-self that lives in every city dwellers heart. Though many of us can’t imagine city as a living being, we have no qualms calling a forest within a bustling city as the Lung of the city. Calling main roads as arterial roads is one such thing because main roads are compared to arteries that carry fresh oxygen rich blood to parts of our body. Such an attribute is quite apt because it is the roads which keep a city moving.
Can we ever imagine an American city without the criss-crossing Inter State highways, flyovers or Germany without its Autobahns? So such is the importance of roads to a city because of its function.
But there is one organ which is constantly overlooked in our body and is quite under-rated. That is Liver. We get reminded of liver only when there is a serious problem like Hepatitis or Cirrhosis and hence the awareness about liver is quite low. It is one organ which cannot be effectively replaced and is very essential for our survival. Interestingly it is the only organ which can regenerate itself when injured and that makes it resilient.
So why am I talking about liver here. Because liver plays a major role in detoxification of blood and there is one such utility in a city which does that. That is Waste Water Treatment Plants, a public utility which is seldom cared for and which does a major role in increasing the livable standards of any city in this world. This utility is constantly overlooked, sometimes even forgotten from the collective consciousness of the city that 90 % of the people wouldn’t know where the sewage from their homes gets treated.
So I call waste water treatment plants (WWTPs) as the liver of the city for it is essential for the very survival of the city itself. With the emergence of extreme weather events like Hurricane Sandy or Bay of Bengal cyclones that hit Bangladesh and India, WWTPs play a major role in resilience of the city to such events. In fact many major firms like IBM, Cisco, and Schneider are marketing their products for smarter cities for the very reason to improve the resilience of the city against such events and effective functioning of WWTP infrastructure is enlisted as one of the prime objective in all.
So what is meant by Smart management of a city? Imagine a room which is filled with dashboards that point to the every activity of the city just like an ICU where the patients vitals on shown on the screen. Smart management of the cities are increasingly going to depend on the data that we are going to harvest from every utility of the city say water supply and gas pipelines , electric lines , roads, storm water management , fresh water reservoir, sensors pointing to ambient air quality and so on. So that is the concept of Internet of Things (IoT) where data from various sensors are collected and analyzed to take remedial actions and the effect of such actions constitute the basis of smart city management.
So coming back, is WWTP an organ or a super organism by itself. The word Super Organism may sound intriguing and can arouse a sense of discomfort within our minds. So what is super organism? The concept of Super organism goes back to late 18th centuries and it means ‘an organism consisting of many organisms ‘. Even our human body is sometimes referred to as super organism for our vital functions are very much aided by billions of microorganisms that reside in our gut. So why is WWTP, considered a super organism? This question needs us to dwell into our past to know how the concept of waste water management and treatment has evolved.
Until last century, waste water treatment had always been considered as a civil engineering problem and the methods to deal with waste water was to pump it out of the city and release it in wetland or river after some treatment. But with burgeoning population, such practices could not be continued due to the resource constraint, that is land and with increased regulation of river water quality. So the problem was probed with a microbiological outlook and that led to introduction of Activated sludge process which uses microbes to reduce the biological and chemical oxygen demand of the water. So WWTPs of today are super-organisms by itself for they are composed of a range of microbes from bacteria to algae to fungi to bacteriophages to protozoans which perform various functions like removing carbonaceous matter, removing ammonia, volatilizing organic matter, denitrifying nitrogenous matter, killing and removing disease causing microbes. They are silently working all day and they have innumerable symbiotic associations, predation and every social association that is found in an ecosystem like forest.
Sewage as we know supports a multitude of organisms and it was found that by encouraging specific set of microbes in the sewage by providing necessary conditions, the pollutants in the sewage can be degraded and sometimes harmful microbes can also be removed. After all, waste water is 99 % water. So this understanding brought a quantum change in how this problem is addressed and made it a multi-disciplinary problem which involves civil engineering, microbiology of soil and water, ecology, control engineering and recently it included data sciences, for we need to make sense of the data that we are increasingly receiving through sensors across the cities through SCADA systems (Supervisory control and Data Acquisition).
Despite all the complexities, waste water treatment hasn’t caught the imagination of people as an interesting problem to be solved because it usually sounds more like a goodwill action to save the planet and does not make an immediate economic sense like creating a blockbuster mobile application which can make a developer, millionaire within a year.
But still, I would like to provide certain facts which might appeal you on why this is an interesting problem to be solved. A recent study shows that cities invest nearly 30 % of the investment in building and maintaining waste water treatment / management infrastructure but get no returns out of that. The treated water is let into the waterways and hence the expression of ‘money going down the drain ‘, is quite true in such a scenario. The major reason why waste water treatment is not taken up enthusiastically in spite of its perceived benefits is because it virtually gives no benefit to the investor other than meeting the regulatory limits of pollution control board. So the waste water treatment plants has to be re-imagined as resource recovery and resource recycling units where in the ‘break-even point’ of the investment should be achieved within a period of time just like how solar power plants are making sense with rising energy prices.
We, the nation of India actually have a humongous problem which needs to be fixed and that is saving rivers and water bodies from ourselves. The billion dollar Ganga Action Plan involved building numerous waste water plants along the river and the end result is Ganga is as polluted as it was. It is called as a failure of epic proportions for various reasons with one being the extreme variation in climate that is found in Gangetic plains. Two months of sweeping hot dry loo winds, months of torrential monsoon rains and two months of freezing cold actually results in microbes getting confused and hence reduced the efficiency of the plants, therein making it a difficult problem. We have to remind ourselves that Gangetic plain is one of the densely populated regions in the world and if we didn’t find a solution soon then we may lose the river itself and a human migration of epic proportion. Civilization around the world have always succumbed to water, be it scarcity or floods.
The famous temple of Angor Wat in Cambodia is actually a vestige of a much larger city which succumbed to acute water scarcity due to the faulty water management/Over engineering of water infrastructure of/by the rulers then. Even the Indus valley civilization is said to have failed due to the exploitation of trees and natural resources which in turn reduced the resilience of the cities due to shifting course of River Indus.
And the last point is the waste water treatment market is really huge and it would be up for grabs once the government privatizes the waste water treatment utilities in line with the global trends. In India, nearly 75 % of sewage in urban areas and 95% in rural areas are now entering our water bodies and rivers untreated for the prime reason that we don’t have the system built in place to treat them. Major foundations like Melinda Gates foundation are offering huge funds for cause like clean toilets for the third world, which is actually a waste management cum design problem to be solved. The world is increasingly moving towards decentralized systems in place of centralized infrastructure and it is said that decentralized systems improve the resilience characteristics of any infrastructure. Hence re-imagining waste water treatment as resource recovery units for individual homes and communities could be an ideal alternative to huge public utility projects which is saddled with inordinate delays and scaling up costs.
Here is a word of caution for all warriors who have risen up to the challenge of creating solutions that matter to billions. Waste water treatment plants are not just an engineering structure or construct which can be controlled. It needs to be managed for they are living ecosystems just like a forest and we need system-level thinking to understand them in order to derive benefits out of them in a sustainable way. They are non-linear systems partly due to the activities of the microbes and partly due to the fact that they are part of our human society, for we humans produce waste water in our homes not in a steady state fashion but in a cycles which peak at various parts of the day . Couple that with huge shocks these plants have to encounter during rains and the ever changing weather conditions due to changing seasons.
Here is a trivia, before I end this note. In terms of volume handled, no other industry handles more volume than waste water and water treatment industry, not even the gargantuan petro-chemical industry.
Friends, Warriors and citizens of the world, lend your ears to the profound statements of the genius. We have come here to solve the problems that the mankind has produced and not create new problems of different kinds by having faulty assumptions in first place.
We have risen up to solve them once for all. Hence, lend your ears to his profound words on solving problems once for all.
Looking forward to your comments and suggestion regarding this piece and objective which is ” Re-Imagining Wastewater Treatment Plants “.
Research Masters Student
National Institute of Technology, Trichy
24 Sep 2014
For further readings:
Bee Hives: A super organism by itself. Read more about super organism in the series by Wired magazine:
Slow Death of River Ganga:
Survival Lessons From an Ancient Failed City:
Performance evaluation of Sewage treatment plants in India:
Megawater-Replumbing the Modern World: Megawater:
(An extract from Dr. Mark Everard’s The Hydropolitics of Dams: Engineering or Ecosystem?)
Third Policy Switch: From Consuming to Building the Basis for Economic Growth: Third Policy Switch: