Septic Tank Baffle System – An Effluent Filtering Device

Name : T.R. Rajeshinnv_rajeshtr

District & State :  Thrissur, Kerala

Category : Utility

Award :   National

Award Function :   3rd National Grassroots Innovation Awards

Award Year : 2005

Innovation Description

55398df3872bc762c717a605018f7dec-971_340x180Rajesh (30) hails from Panancheri panchayat in Thrissur district,Kerala but in the span of his 30 years has wandered and worked in most of India with the exception of Manipur and Kashmir. The eldest of a family of three sons, he left home to fend for himself and did everything from working in a lathe workshop to marketing various products from machinery to liquor. He is presently involved in construction work. He is married and lives with his mother and two younger brothers who are goldsmiths.

The Genesis

While working in the construction business, Rajesh felt that the present design of making baffles in septic tanks was too expensive and that he could come up with something simpler. He backed it up with research and borrowed books on Engineering from the public library in Thrissur, of which he is a member. He could, however, lay his hands on only one book on Sanitary Engineering. After reading everything he could on the subject, he thought about it for about two weeks and developed a prototype, to which he made a few modifications. He then installed it in a neighbour’s house, where he had been entrusted with the job of constructing the septic tank. Five years since the installation, no problems have been reported

The ingenuity behind the innovation holds the listener’s attention. The septic tank is a combined sedimentation cum digestion tank where household sewage is treated. The lighter solids including grease and fat rise to the surface to form “scum” and the heavier solids settle down in the tank to form “sludge” which is gradually decomposed by bacteria. The liquid waste or effluent goes into the drain field and undergoes oxidation. The baffle helps to reduce the disturbance of the settled sludge and keep the solids and scum in the tank. In the conventional septic tank, two baffles made of concrete are used. However, in Rajesh’s innovation, only one baffle made of PVC pipes is necessary. This circular baffle which consists of three chambers works as a divider and filter.


The system is cost effective, because, instead of a normal septic tank measuring 2.6m by 9m by 1.8 metres costing Rs.10, 000, by using this unit inside, the size of the can be reduced to1.8m by 9m by 1.8 metres. This results in a saving of Rs.3500. Other advantages include a greater capacity for settling, digestion and storage of sludge, the clearer effluent that is relatively free from stench and particles of excreta, and above all the sheer simplicity of the idea.

The future of STBS

Though friends and family believe in his ability and have supported him in his endeavours, Rajesh laments the lack of institutional support for his ideas. He had initially approached a premier research institute in his area with his idea for the baffle system, but did not get a satisfactory response from them. He later saw an advertisement of the contest sponsored by National Innovation Foundation in The Hindu and applied. NIF has applied for a patent on his behalf and the number is 806/CHE/2004, August 17, 2004. Rajesh hopes that NIF will be successful in finding someone who is willing to invest in it and commercialise it. He has not received any support from the Panchayat or government authorities. He did not approach them with his idea as he did not want to give undue publicity to his innovation, since it is still in the process of being patented. On being asked whether he would like to set up his own business by commercialising this innovation, he firmly declined as he has already tried his hand at running a couple of businesses which made huge losses and had to be shut down. NIF has sanctioned him Rs.62,500 from the Micro Venture Innovation Fund for making the prototype to conduct market survey of the innovation.

On Research, Education, Religion…

Rajesh’s strong and passionate opinions often extend to myriad subjects. He laments that the present system of research is just an extension of a master’s degree and MPhil and hence the student feels obliged to take a Ph.D. There is no genuine interest in finding something new or devoting oneself to it as in the Western approach. His comments on the current system of education are scathing- it stifles independent thinking and children end up mindlessly mugging up details that make no permanent impression on them. They do it as a means to an end- getting the certificate or degree but not for learning. Belief in God has not been a part of his life since he was 12 years old, but at the same time he does not impose his views on his wife and family. He believes in certain universal truths and the fact that the power is within oneself. He holds the belief that one can find that peace within oneself, and need not seek it in places of worship.


As a child, he wanted to become an engineer, but now his greatest dream is to get sufficient income so that he can devote his life to what he likes best- research. But rooted in reality, he admits that the exigencies of eking out a living have reduced his time for reading and keeping himself updated with the latest developments in the world of science. He foresees that if this state continues, in a number of years his mind would become stagnant and ideas might no longer flourish in it as they do now.

A stoic view on life…

He states unhesitatingly that he has seen all sides of life – there have been times when he slept hungry on a pavement and times when he has been flush with funds. He has been through the crucible of life and is able to view most things with equanimity. With time he has also begun to understand what makes him tick- the fact that routine, mundane work does not interest him and that he needs something challenging and difficult to work at his peak. When one subject captures his attention, he focuses on it to the exclusion of everything else. His ideas and their development give him satisfaction.

An asset to his community

Rajesh has proved invaluable to his community in solving various problems- be it of a technical or social nature. He often finds himself counselling friends and advising them on all matters- professional as well as personal, helping school children with difficult maths and science problems and volunteering for various social causes. According to Mr. Chandrasekhar, a school teacher whom Rajesh often consults, “he has a brilliant mind and needs to be encouraged”. Mr. Vinayan, a community leader, who has constantly offered encouragement for his endeavours, concurs and hastens to add “what makes Rajesh stand out is his humility and ‘open-heart’- he treats everyone equally”.—An_Effluent_Filtering_-Device/296

Leave a Reply

Name *
Email *