The precious ground water, which is utilised for washing utensils, clothes, bathing and ablution purposes in each household, finally ends up as sewage inside Bengaluru’s sewerage lines. With the risk of acute water shortage at our doorstep, can we afford to waste so much water? How much of this water can be reused? Are there ways to reduce and redirect our waste water for better purposes?
Plants such as Papaya grown using human waste compost Pic: Kedar Nadella
Ecological Sanitation, or Eco-San, is a relatively new philosophy that refers to low and high tech processes of an economically sustainable waste water management system, keeping in mind not only the population at large, but also the individual’s needs.
“Ecological sanitation covers three broad aspects – Conserving water by using the minimum quantity required, safe and hygienic methods of waste management, ensuring recovery and reuse of nutrients and organic matter,” says K Vishwanath, eco-activist and founder of Rainwaterclub.org in Bangalore.
The ecological sanitation graph of a city is determined by the treatment of waste matter of the city, from its origin to its dispersal into the environment. Eco-San goes beyond the conventional and often fallible methods of disposing wastes prevalent in the city’s waste management system.
The grey water waste (water generated from domestic activities such as laundry, dishwashing and bathing) and human excreta from communities, industries and other institutions is collected and recycled for human use through various means. This is better than dumping it invariably into urban water bodies which can lead to contamination of potable underground water.
Not enough water in sewerage lines
Bangalore faces many problems in disposing sewerage waste. Conventional drainage systems demand 150 litres per head per day for sewage to flow through it. Otherwise it causes blockage in the lines. With Bengaluru’s population heavily dependent on the Cauvery water, and the potential of rainwater harvesting not yet fully realised by the city’s residents, 150 litres per capita per day of water to fill the drainage system is a luxury that Bangalore cannot afford.
When there is not so much water present in the system, the waste dries up and leads to blockages. Though the BWSSB removes the blockages with jetting machines, a long term solution is required to prevent blockages and resultant leaking of sewage onto the streets and houses.
Honeysucker machines – a long-term solution
Eco-sanitation methods advocate the use of Honey-suckers or septic tank cleaners, for disposing human waste. They are transport vehicles which collect human wastes from Individual houses and small Sewage Treatment Plants (STP) in large storage tanks and dump the waste on farmlands. A case study has been done on the business of Honey-suckers in Bengaluru by IRC International Water and Sanitation Centre, The Hague, The Netherlands and the International Water Management Institute, Colombo, Sri Lanka in 2012.
Honey-sucker machines collect human wastes from the septic tanks of houses all over Bangalore. Pic: Priya Desai
The study found out that with the absence of a city-wide sewerage network for about 63% of population in Bengaluru, Honey-suckers can provide relief to the residents by efficiently collecting and dumping their wastes on the fringes of the city. The three-fold benefits of this process include
- The residents getting a hassle free riddance of their wastes without any extra effort.
- The honey-sucker tanker owners earn money for the transport of wastes from the cities to farmers in the outskirts.
- The farmers save money by avoiding the purchase of chemical fertilisers for their fields.
There is no legal framework yet that regulates these honey-suckers and their activities. K. Vishwanath cautions that if government regulation is imposed, it is likely to hamper their growth and long term sustainability. Currently Honey-sucker machines are operational in some parts of the city like Richmond street; they have not yet got wide acceptance from the public.
An Eco San separating pan Pic: Kedar Nadella
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Eco-sanitation toilets
Eco-sanitation toilet systems use least amount of water and collect the solid and liquid wastes separately for further use. The construction of an eco-sanitation toilet is relatively simple and the toilet is easy to use. K Vishwanath has been an advocator of eco-san toilets since many years and has written many articles on its advantages.
Bangalore is not a stranger to this alternate method of waste disposal. Acharya in IISc (Indian Institute of Science, Bangalore) in 1939 had developed the Bangalore method of composting which uses the single pit method of collection of human waste. After alternate application of aerobic and anaerobic method of composting, the waste is converted to plant fertilizer.
Tin drum for faeces and barrel for urine collection. Pic: Kedar Nadella
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“The drawback of eco-san toilets lies in its implementation in the urban areas,” says Priya Desai who is a Project Manager at Arghyam, an NGO working on water-related issues. “People in the cities who are used to the conventional flushing type of toilets will find it tough to adapt to eco-san type of toilets.” she adds.
Pilot projects in eco-sanitation
Though not implemented in large numbers, many pilot projects have been conducted by a handful or organisations and individuals who have brought forth the benefits of eco-san.
Dr G Sridevi, guided by Professor C A Srinivasa Murthy of GKVK College of Agriculture (Department of Soil Science and Agricultural Chemistry) and funded by Arghyam, was the first one to obtain her PhD on Eco-san in 2009. Her research includes a comparison of maize, banana and radish plants that were fertilized using human urine (Anthropogenic Liquid Waste, ALW) to the same group of plants fertilized using chemical fertilizers, providing the same nutrients. Results pointed that plants grown using ALW were of better quality than those grown using chemical fertilizers. There were considerable improvements in parameters such as grain yields in maize and yields of banana. For farmers, this not only gives better produce but also avoids the initial expenditure for chemical fertilizers.
Another pilot project was implemented by ACTS, an NGO working for the environment, which constructed an eco friendly toilet centre in Rajendra Nagar, Bangalore, in 2001. Their objective was to build a hygienic waste management system that would divert the human wastes for the production of biogas which could then be used as a substitute for LPG. The eco-san toilets were used from August 2001 till the project’s expiry in January 2006. The results indicated that with a strong local organisational embedding and a good long term management, ecological sanitation will foster community health and the consumption of bio-friendly fuels.
A urban sanitation workshop conducted by UNICEF in Bangalore in 2008 enumerated the positive features of waterless urinals and the implementation of eco-san toilets all over the world.
With government’s aim to eradicate open defecation by 2017 through Nirmal Bharat Abhiyan, they should also consider promoting Ecological Sanitation which can make up for the drawbacks of conventional sewerage systems and safeguard the health of the environment and people. Bangalore needs to wake up to the reality and welcome the new methods of waste disposal, for a sustainable urban waste management system.⊕
human waste as fertilizer U say? What about things like Ascariasis and trichuriasis which may caused by the agriculture produce which is grown from infected waste?