A wastewater treatment system in a residence

Ravi Iyer’s home is surrounded by a bright green garden and lawn even at the peak of summer. Plantains and other trees, flowering plants and creepers thrive here. Located along Sarjapur road, Iyer’s layout gets no municipal water supply at all. For years, he had used tanker water for all purposes, including gardening. Then around 2014 he installed a greywater treatment system; the treated water from the system feeds the garden now.

The reed bed-based treatment system here gets wastewater from the household’s kitchen and washing machine. Treated water is stored in a 750 litre Sintex tank underground. Additionally, separate pipes carry RO reject water into this storage tank directly, without treatment. Iyer says that the tank gets full in a week usually, though it could vary depending on use of washing machine. The water is pumped up and used for gardening every alternate day. Thus even in the parching summer, the garden and lawn gets water that would otherwise have wasted away in the city’s drains. Iyer says that no freshwater is used for gardening here anymore.

He says that when the system was first installed, the odour of treated water was a concern. “Then we realised it was because of treated water stagnating. If we let it out routinely, there is no issue. So we let water into the garden even during rainy season though the garden does not need it then.” He says the system is hassle-free since it is zero maintenance. “Only the storage tank has to be cleaned every couple of years. We have got it done once – water is put into the tank and then sucked out, that’s all,” he says.

Capacity for treatment 200-300 litres daily
  • Pipes to carry greywater from kitchen and washing machine
  • Baffle filter with two chambers – settlement chamber and grease trap – of dimension 3’X2’X2’
  • Reed bed of dimension 6’X2.5’X3’. It is a concrete structure filled with jelly, in which reeds grow
  • A settling chamber for treated water
  • Storage tank of 750 litre capacity
  • Pipes to carry RO reject water
  • A settling chamber for RO reject water
Description of implementation Pipes are connected to carry wastewater from kitchen and washing machine into the underground baffle filter, and from here into the reed bed/planted gravel filter. Filtered water then flows into a small settling chamber where sediments settle, and then into the Sintex storage tank lowered underground. Separate from the treatment system, pipes carry RO reject water into another small settling chamber, and then directly into the storage tank. Water in storage tank is pumped up using a ½ HP motor into a tap, from which water can be taken for gardening.
Treated water available About 750 litres per week
Cost of implementation Rs 50,000
Time taken Less than a month
Any issues at present None
Contact water@biome-solutions.com

Urban Waters, Bengaluru