Safe disposal of waste

The U.N. has declared November 19 as World Toilet Day to focus attention on the much needed aspect of sanitation and its lack in many parts of the world. While a toilet is essential to provide the much needed privacy and dignity, the disposal of waste by itself is not enough. We need systems which safely transport and treat the waste so that it does not end up spreading disease or polluting our rivers, lakes and groundwater.

Since it is caveat emptor in the real estate market, before buying a flat or a home ask and assure yourself about the sustainability and long-term availability of the water source. Also ask where the sewage is going and whether a sewage treatment plant has been set up with adequate technology to treat the waste-water generated up-to reuse standard. Buyer pressure will eventually force builders who may be recalcitrant to invest in safe, adequate and low-maintenance base sewage treatment plants.

Design matters

In individual homes make sure that the architect or the engineer designs systems for the safe containment and evacuation of waste from the toilet. If an area is not served by sewerage and has no sewage treatment plant it will be served by on-plot sanitation systems. These must be robustly designed, not pollute groundwater, be able to be easily cleaned and the pit must be designed to be evacuated mechanically and easily.

Twin leach pits are a very good alternative to serve your toilet. Only toilet waste goes into one pit and when that is full it is diverted to the second pit. While the second fills up the first will have safely decomposed and can be removed and used as manure.

Correctly designed septic tanks are a must but even better are systems that further treat the liquid effluent using planted gravel beds or the newly designed vortex system.

Here the liquid effluent from the septic tank or a baffled reactor is spun through a vortex which increases the dissolved oxygen level and helps eliminate bacteria as well as reduce BOD.

Vertical soil- and filter-based systems are also available to treat waste-water using biological means. This cleaned water can then be used for gardening or toilet flushing.

In poorer areas, the steeply sloping pan can be used with the twin leach pit. These Indian style squatting pans demand as low as 1.5 litres of water for a flush, thus considerably reducing the need for precious water.

In the rush to build toilets one should not forget the end place where all the waste ends up. A systems thinking approach will help manage waste scientifically and recover precious water and nutrients.

In the city on the same day as the World Toilet Day a ‘Krishi Mela’ or farmers fair was going on.

Here on display were crops such as soya-bean, chillies and millet showing highly productive growth using sludge from pit toilets. A clear demonstration of closing the nutrient cycle.

What is waste for us is food for the plants and what is food for us produces the waste as nutrients for the plants.

Correctly designed septic tanks are a must, but even better are systems that further treat the liquid effluent using planted gravel beds