Grey water in India

[martin.laf]

#853

The context:
Increasingly dense urban environment with shortage of water;
The client:
Middle class household;
The space:
1 Meter between the house and the compound wall;
The water:
Only grey water, no kitchen washing water but kitchen vegetable washing sink. And of course plus washing machine and showers/ sink;
The intended usage:
Flushing toilet and watering garden;
Outcome desired:
Non smelly water and as much as possible, color less;

The solutions we have done:
– Simple small baffle tank to seperate solid and so reduce oxygen demand;
– Slow sand filter: 1 foot free board + 1 foot 1mm sand + gravel and drain pipe.
Sizing:
Water remains in contact with the sand approx 6 hours

Result after one month:
– Water is fairly clear, down to one foot we can see through. Smell, still very little.

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Anybody would have inputs on to improve this system or quideline in sizing?

Thank you