G O B A R S P E A K
K M E
What is meant by Dry composting toilet? How does it work? How are the separated excretes,
urine and faeces disposed? What happens to ablution water? Can this system be used in
Dr. Girish Udapudi,
Dry composting toilets are ecologically sound methods of sanitation. It minimises water
use, recycles nutrients from human excreta and prevents water pollution. Ecological
sanitation can save upto 25-30 per cent of household water consumption.
In most ecological sanitations, the urine and the faecal matter are diverted at the
source and treated separately. Separating at the source helps in recycling wastewater
efficiently. The faecal matter is used for improving soil conditions. The urine is used as
a liquid fertiliser, which can be connected to a plant bed or a field.
Using blackwater (a mixture of faeces and urine) as a fertiliser can be best achieved
by blending in organic household waste or farm manure and composting.
Paul Calvert of Ecosolutions
has designed a compact system, to suit urban as well as rural locales. To know more on
ecological sanitation, and contact experts who could guide you, visit the following
I find that the water in my area is hard. Can you tell me methods to decrease the
There are simple home-made methods to soften or reduce the hardness in water. The hardness
in water is caused by a high content of minerals or metal ions, mainly calcium and
magnesium in the form of carbonates and sulphates. To remove the hardness, the ions are
exchanged for sodium or potassium ions.
Temporary hardness, caused by carbonate ions, can be removed by boiling. In the
process, a scale forms on the inside of the vessel. This is made of insoluble calcium
The most economical way to soften household water is with an ion exchange water
softner, by using sodium chloride or common salt. The principle is the same, where the
ions of hardness-causing minerals are exchanged for sodium. The hardwater passes through
an ion exchange resin made of beads (artificial or natural zeolites). Ion exchange resins
do not remove chlorine or organic contaminants in water. This is done by using charcoal,
usually not done in homes.
I was quite excited to read your story on urban birds. I have lived in Bangalore on and
off for most of my life. The common saprrow was one bird which was in abundance in eariler
years. Today, I cannot see a single sparrow. What could be the reason? What have we done
to make this bird disappear? What can we do to get it back? Sometimes I travel to smaller
towns in Punjab and am delighted to see hundreds of sparrows there...The only birds I now
see in Bangalore are the crows and in the mango season, the koels and parrots.