When we use freshwater in our home it is typically divided into — sewage water and greywater. “Sewage water comes from flushing toilets, while greywater originates from all other activities, such as taking baths, washing clothes, washing utensils, mopping the floor, and any other activities that do not involve sewage or urine,” he says.

Unlike black water, which contains sewage and toilet waste, greywater is relatively clean and can be recycled for various non-potable uses, such as irrigation, flushing toilets, and landscape watering.

There are many cost-effective filtration methods with a 1,000-litre capacity that can help a family to reuse water, the activist says. Recycled greywater is safe for use as it does not involve direct contact with the human body nor is it used for consumption, hence not affecting our physical health.

Setting up such filtration methods are relatively easy and cost-effective, contrary to popular belief, points out Subhajit. “A basic home setup for recycling 1,000 litres of greywater can be established with an initial investment of approximately Rs 10,000. Moreover, larger facilities like housing complexes or educational institutions can implement extensive recycling systems, with costs not exceeding Rs 20,000,” he says.

These systems not only recycle water but also allow for percolation into the ground, aiding groundwater recharge and helping mitigate urban heat island effects.

If you want to use recycled greywater for flushing a simple sand filter would work.

“However, if we want to use it for mopping floors or washing cars, then we use a 5 Micron filter which will filter out all the detergent and harmful oil from the water.”