Saving Grace...

"What inspired you to do this?" That was the one question I had for him.

In response, he recounted his childhood in the water-deficient Coimbatore region of Tamil Nadu. When the water was in supply, he'd had to stand in line at 11 in the night to get water the next morning - a routine that spanned his teens and lasted till he turned 22, when he moved out to pursue a job after college. 

Today, he is an upwardly mobile middle-class Bangalorean, working – as is typical for the demographic –with a multinational technology company. He lives in a three-bedroom house in Mariyannapalya, a house that is a testament to his passion for, and his awareness of his obligation towards, sustaining the environment. 

The house is built with mud bricks, which, I faintly recall, are known to keep both the heat and cold outside from bothering the inhabitants as much as they do in ordinary constructions. The house also has a sky light that lessens dependency on artificial illumination, and when the latter is necessary, the low-power electric light sources are animated by a current generated by solar panels on the terrace. The flooring doesn't consist of the vitreous tiles in vogue or the grandiose granite, but tiles – I forget the specific material – that are highly-effective insulators and "let you walk barefoot in the coldest months."  If none of this impressed you, it is mostly because I am too ill-informed to channel my own awe into words.

Speaking of awe, it was what he did with water that made me ask the question at the beginning of this post. In the front yard, there are three sumps. The largest of them, holds the water supplied by the civic body – a supply that runs dry in the summer and makes cameo appearances through the rest of the year – as well as the rainwater runoff from the carefully sloped terrace, the water entering the sump via a sedimentation filter. The next sump, having a capacity of 2000 liters, is fed by the rainwater that strikes the ground area open to the skies, after passing through a sort of sieve that separates the leaves and other debris. The third is a 300-liter container for grey water.

A motor pumps water from the largest sump to an overhead tank as determined by an automatic water-level controller. The water from this tank flows out of the taps and is used for cleaning and washing, brushing and bathing – you get the idea, don't you? He pumps the water out of the second sump when needed, and uses it to wash his car.  

And now, it's finally time to treat the grey water. This is the water drained from the wash basins, the baths, and the laundry. The outlet of the kitchen sink has been left out of the grey water network because of the grease the dish wash is likely to have. This water from the smallest sump is pumped to a second overhead tank by another automatic water level controller. The water from this tank flows through a cascade of six concrete columns, each shorter than the one before, and finally, into another storage tank. The columns are arranged in two rows of three units to conserve space.

Water flows out of a column on rising to the point where the column has been tapped. It flows into the next column through a downward pipe, whose decline is due to the difference in heights between the columns. Each column is filled with gravel, and as the water rises through the gravel, it gets filtered. Atop the gravel is a reed bed, and the reeds absorb the nutrients in the water, purifying it further. After five rounds of filtration through the gravel and nutrient absorption by the reeds, the water is directed into the bottom of the last column, packed with layers of gravel – coarse gravel at the bottom, and finer and finer gravel towards the top. The water that rises to the top of this column is filtered through these gravel layers with diminishing gaps and let out into the storage tank. A network of pipes takes the water from this tank into toilet cisterns, and the water is used for flushing before finally being discarded as sewage. 

While it sounds and seems like child's play, the system, he says, comes with its own set of posers. Yet, it is hard to ignore his child-like enthusiasm for tinkering with the system to better its output, including switching to low-phosphate organic detergents he makes at home for washing the clothes to experimenting with a probiotic bacterial solution to raise the efficiency of the reed bed. 

He quantifies the gains, too. With the erratic water supply in his area, the ever-plunging underground water table, and the poor quality of the water drawn through borewells, houses and apartment buildings in his neighbourhood are largely reliant on water supplied in tankers, water whose origins are unknown and prices, steep. Most households dial a tanker of water every week. With his rainwater harvest system and the grey water treatment system, however, he has been successful in reducing his dependence on the tankers. In the last year, he says, he bought only eight tankers of water, predominantly in the summer months. And, interestingly, his gains derive from a few thousand rupees spent initially on building his water systems.

For those of us, who are indifferent to the water scarcity dogging Bangalore, have reservations about  the harmless reusing of the grey water, or spout principles of frugality to justify our reluctance to invest in such systems, he has two simple questions: "If not now, when? If not you – the educated and financially capable – then, who?"