Why does your drain smell so bad?

TNUSSP banner_02 may 2018

So, you have finished using the toilet. And, have flushed it down. But seriously, where does it all go?

When you ask this question, the answers you get will range from septic tanks to pits to the underground sewerage systems etc. But, is that the whole story? Now that is the difficult question, which begs a real hard look at the ground reality.

Let’s travel some years back in history. It is a well-known fact that ancient India had a fine network of storm water drains, which acted both as groundwater recharge systems, as well as flood control devices. In cities like Chennai, the network of storm water drains led to ponds (kulams) which acted as natural flood control devices. Thanks to unbridled ‘development’ and growth of unplanned settlements both these ‘kulams’ and the storm water drains are polluted and choked.

How have things come to this state? One of the major contributors of pollution in storm water drains (SWDs) are the people themselves. This happens in three ways:  Many of the households, which have no containment structures attached to their toilets, connect the toilets to the storm water drains.  Sometimes, even households, which have containment structures, connect the outlets the storm water drains. Thirdly, it is not unusual to see that the grey water from the kitchen and bathroom being connected to the storm water drain directly.

A study conducted by Tamil Nadu Urban Sanitation Support Programme (TNUSSP) on the state of the storm water drains showed that this kind of pollution was not only common in small towns but also in mega cities. When asked why toilets and containment structures were connected to storm water drains, most of the residents said that they used the storm water drains as an easy option because it was the “common practice in the area.” Some of them also mentioned the “lack of other options” as one of the reasons.

Letting grey water from the kitchen and bathroom into the open or closed drains is a very common practice all over the country. This is also because many of the people believe that storm water drains are meant to carry the grey water. It comes as a surprise to many people when they learn that storm water drains are meant only to carry storm water and urban runoff (surface runoff of rainwater) to the natural water bodies.  However, in reality, the storm water drains end up carrying all the wastewater from the cities (and towns) to the natural water bodies resulting in the grand scale pollution of the water bodies and leading to a colossal public health hazard.

How does dumping of solid waste affect drains?
Dumping of solid waste in the drains is another huge problem that affects the functioning of the drain itself. The drains are designed based on certain set of criteria like the amount of rainfall in the area, natural slope and type of soil etc., which helps to estimates the amount of storm water that will get collected in a particular area. Dumping of solid waste and wastewater into the drains affect their functioning, resulting in improper flow, siltation and stagnation of water which further leads to a whole range of problems like bad odour and serving as a breeding ground for diseases like malaria, dengue, etc.

Where does it end up?
The final destination for the wastewater, which is carried by the drains are the natural water bodies such as streams, rivers, canals etc. A research into how these waterbodies have transformed over a period of time into gutters carrying dirty water will help us understand how we are killing them slowly.  Not very long ago, people used to stop to look down bridges to enjoy the scenic beauty of clean, flowing water. Today, they cover their noses and try to get away as soon as possible.

To understand this problem better, the TNUSSP team conducted catchment level assessment of drains in selected locations. Watch this space for further insights into the study.

For Further Reference:

  1. (http://www.downtoearth.org.in/news/what-drains-mean-to-cities-44069, 2014)


sancy photo




Olassayil Sancy Sebastian
Junior Specialist, TNUSSP






Suneethi Sundar
Specialist, TNUSSP


A day out with the honeysuckers

Working in sanitation throws up many interesting possibilities and questions. One such question was about the ‘hidden taskforce’ of septage management – the desluding workers – who work behind the scene, who are hardly acknowledged, but who are the prime players in septage management. Theoretically, we know that unless the collected septage is carefully desludged and safely transported from the containment structures to the treatment plant, no amount of securing the rest of the links in the sanitation chain would ensure safe sanitation. However, we barely interact with the desludging operators and know far less about their work on a day-to-day basis.

With dry toilets being declared illegal, and more and more houses moving towards toilets with septic tanks, a set of budding entrepreneurs are appearing in the market with their vacuum trucks known as honeysuckers to empty the septic tanks for a small fee.  We also read regular articles in the media about illegal dumping of septage into water sources and open grounds, which creates a huge health as well as environmental hazard.

Given all this myriad information, we decided to find out more.  So one fine morning, my colleague Suresh and I decided to get on to a desludging truck and find out what one day in the life of a desluding operator looked like. We got on to a desludging truck….

Before he turns in the ignition key, let me introduce you to Kumar, our lorry driver. A resident of Sathyamangalam, Kumar travels around 70 kms each day to reach his workplace in Coimbatore. Around 8:30 am, each morning, Kumar teams up with another one or two people and sets out on that day’s business. Today, he has one assistant, Muthu with him, but since the two of us are also around, he has asked Muthu to go and sit on top of the vacuum tank, while the two of us take our place next to the driver.  Once we are comfortable, Kumar informs us that we are going to a poultry farm near Kaattampatti for the first desludging operation of the day.

Two hours along the Pollachi Highway brings us to Kaattampatti. We make our way to one of the largest poultry farms in the district. As soon as we enter the premises, a couple of workers come our way with cans of phenyl, which they pour on the lorry to disinfect it.  The ease with which the entire exercise is carried out makes us realise that the farm is among Kumar’s regular clients.  After the ‘disinfecting’, the lorry proceeds to the place where the septic tanks are situated.

20170722_142120Once the ignition is switched off, we watch in amazement at Kumar’s metamorphosis. He is no longer the chatty person who was sitting beside us behind the wheel. He jumps down from the driver’s cabin, reaches the septic tank and breaks open the sealed manhole with a crowbar. In an equally well-coordinated move, Muthu pulls down the extension hose from the top of the truck, connects it to the valve embedded on the tanker, and pushes the other end into the septic tank. Thanks to the vacuum suction technology, the vacuum tank is filled with 5000 litres of septage in a few minutes.  Throughout the entire process, Kumar has kept a careful watch on the volume gauge mounted on the tanker.


While this entire exercise is taking place, Suresh and I introduce ourselves to the staff of the poultry farm.   After some initial hesitation, some of the workers began speaking to us. We get to know that close to 90 workers work and live on the poultry farm. They share common sanitary facilities, which are spread around the farm, and on an average around 15 lorry loads of septage was being generated by the farm every month. Our jaws drop on hearing this number. “Where do they take so much septage? What is the disposal mechanism,” was the question on our minds. We keep a straight face and ask Kumar where the nearest dumping location was. “Oh, I have an arrangement with the nearby farmland,’’ he says confidently. “We will go there in a while,” he adds.

20170722_171938Surely enough, half an hour later we are at a large coconut grove. With the farmer’s wife supervising the unloading, Kumar and Muthu empty the entire tanker into the groove. We take the opportunity to speak to the farmer’s wife. She tells us that her farm receives around 20 loads of septage every couple of months. “It is not only from the poultry farm, we have an arrangement with a couple of other places for regular supply of septage,” she says with a smile. Her husband who had joined her tells us that the septage is very important during dry spells when the farm faces acute water scarcity.

Soon it is time for lunch. The owners of the farm invite Suresh and me to join them for lunch. Kumar and Muthu have brought their lunch along with them. They go to a nearby tap and begin washing up.  I watch as Muthu fumbles around in the driver’s cabin and pulls out a used detergent soap wrapped in a newspaper, which he and Kumar use to clean their hands and feet. The sight is a kind of relief for us, as we had observed the two carry the hosepipe from one septic tank to another on their shoulder, wiping the spillage with their bare hands!

Once lunch is done, the work continues. Kumar and Muthu take turns building mud bunds around the coconut trees, with their bare hands, to prevent spillage and overflow. The farm owners’ small children continued to play in the vicinity. One toddler keeps coming to Kumar and Muthu and the duo keep embracing him, carrying him, playing with him throughout the time they are working.

It is late in the evening, when the work is done. It is time to head home. On our way back, we find out that both Kumar and Muthu had dropped out of school and taken up this profession. Kumar earns close to Rs 17,000/- per month, while Muthu earns Rs 12,000/- .
As we near Coimbatore, we stop at a roadside teashop. “Take that smelly truck away,” someone shouts from inside.  We look at Kumar. He has a defiant look on his face, but his voice trembles as he says, “There is no point in getting into a brawl. This is our profession and we are proud of it.

Vinitha Murukesan
Environment and Sanitation Analyst, TNUSSP
Suresh Kumar
Community Coordinator, TNUSSP

Linking Information Technology to Fecal Sludge Management

Fecal Sludge Management (FSM) is a management system that safely collects, transports, and treats fecal sludge (also called septage) from pit latrines, septic tanks or other onsite sanitation facilities (OSSF). One of the key components of fecal sludge management is the safe transportation of fecal sludge from the onsite sanitation facility to the point of treatment. There is no doubt that safe disposal of fecal sludge is the primary objective of any FSM project, and the fecal sludge transporters play a key role in this process.

In fecal sludge transportation, different stakeholders are involved in the successful transfer of sludge from containment to the treatment facility. These stakeholders include households, service providers, sanitary workers, septage truck owners and officers from the Urban Local Body (ULB). However, it is commonly seen that these different stakeholders do not work in a co-ordinated fashion when it comes to transporting fecal sludge from households to a treatment facility.  It is in this case that technology can come to the rescue.

At present, the existing system is not fully equipped for holding, retrieving and maintaining information on sanitation facilities including service provision. For example, no authorised body in the ULB has complete information on Households (HHs) sanitation facility, fecal sludge containment and fecal sludge flow. This lack of information and communication will, in the long run, account for badly managed sanitation systems. In this scenario, it would be interesting if fecal sludge transportation followed a system like Uber or Ola cabs using an application.

Let us examine this idea a little more closely. What do the residents want from any service? 1. Reliability, 2. Efficiency 3. Cost effectiveness. All these three are available in the Uber and Ola Apps. These transport services are using mobile web-based GIS technology to provide real-time information about the vehicle, vehicle number, contact number and approximate cost (based on travel distance, total travel time and base fare). Once the service is complete, the customer is asked to rate the service for efficiency.

While this system can be easily adopted by the ULBs to reach customer locations as well as keep track of the septage trucks, the ULBs are wary about its misuse because once the mobile has been turned off or the app has been uninstalled, it is difficult to track the vehicle. However, if we keep in mind that the core aim is to provide customers with better services, and not just prevent illegal dumping of fecal sludge, these small lapses can be set right.

FSM projects in countries like Senegal have established the world’s first innovative call centre system to enable the customer to receive the best and most economical service for desludging. This system operates on request-based desludging not schedule-based desludging. The clients send their request for desludging to the call center, and the call center contacts the operators near the said client’s location for quotations. The call center, then sends the lowest quotation to the client based on which the client asks the call center to send a particular desluding vehicle. Once the desludging is completed, the call centre calls the client to check for customer satisfaction.  This system works well, but requires transparency at all levels to be sustainable in the long run.



The integration of GPS, GIS, GPRS and the mobile-based web application for Urban Local Body, service providers and residents will improve the quality of service, are easy to monitor and ensure safe environment. GPS will provide the current position, GIS will provide route directions and how to get there (simple algorithm for path finding using different aspects shortest path, regulated path and travel time), while GPRS will provide real time data, through the mobile towers.

If the FSM project needs to be successful, it should follow the improved service orientation approach not just monitoring approach. If the sludge transport system has to run successfully for long periods, the process has to be transparent, and it should benefit both clients, as well as the service providers. Towards this end, all stakeholders have to sit together and discuss the possibility of an improved service-oriented approach to create a better environment for everyone to live in, and this approach should be facilitated by the Urban Local Bodies.


Navamani Ramasamy
Specialist, TNUSSP