India faces the dual problems of inadequate potable water supply and pollution from untreated used water. This is mainly due to the colonial legacy of centralised water management that ignores the economically and ecologically sustainable household and community level circular water management, which is schematically depicted in the accompanying graphic.
The key to circular used water treatment and reuse is the separation of grey water (from kitchens and bathrooms) and black water (from toilets):· Grey water accounts for nearly 85% of total used water and is easier and cheaper to treat.· Low-cost methods such as filters filled with 25 mm brick pieces and with canna plant roots can clean grey water to prescribed standards.
· Black water treatment is costly due to the faecal matter in it. When grey and black water are mixed, as in centralized systems, costs rise significantly due to transportation, treatment in Sewage Treatment Plants (STP), sludge management, and infrastructure for reuse of treated water. Sewers need a greater water flow to prevent deposition of the faeces in transit and so it is imperative to mix grey and black water in centralised systems.
A very good example of circular grey water management, in this sordid context of its overall neglect in this country resulting in polluted water bodies, is the newly commissioned grey water treatment and reuse system at the Swami Vivekananda Vidyapeeth campus in Sehore district of Madhya Pradesh (https://lnkd.in/dw6NGFEE) run by the NGO Parivaar shown in the picture below.
· Three treatment chambers with 25mm brick pieces hosting beneficial microorganisms.
· Canna plants in the second chamber absorb nutrients and enhance purification.
· Hydraulic retention time of 3–5 days ensures that for the treated water collecting in the fourth chamber, all the important parameters such as ph, Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Dissolved Oxygen (DO), Total Suspended Solids (TSS), Total Nitrogen (TN), Phosphorus (P) an d Faecal Coliform (FC) are as per the standards prescribed by the Central Pollution Control Board as shown in the table.
· Automated disinfection with bleaching powder (5g per kilolitre) before reuse.
· Treated water reused for toilet flushing and gardening, replacing costly potable water.
The installation cost of this system is only ₹30000 per kilolitre and the operating cost is ₹3 per kilolitre without the need for any electricity. Whereas, centralised used water transportation through sewers and treatment in STPs has a combined installation cost of ₹100000 per kilolitre and a combined operating cost of ₹25 per kilolitre. The cost of reusing the treated water in this localised circular system is low as the point of reuse is near to the treatment plant. Thus, Parivaar has set an example that should be replicated widely.









The Subedar or Governor of Burhanpur Abdul Rahim Khankhana commissioned a Persian geologist Tabukul Arj to devise a system that would be able to harvest the rain water falling on the Satpura ranges and bring them by gravity to the town in 1615. A very ingenious plan was drawn up wherein a few large tanks were constructed to harvest the rain water and recharge it into the ground. Finally a 3.5 km long tunnel about thirty feet below the ground level, lined with marble, was constructed just uphill of the town into which the water from the t Bhandaras seeped in through the ground.
There are 103 round wells that reach this tunnel from the top at intervals and provide access to it for cleaning it of any debris and sediments that might have accumulated. The water in the tunnel flows by gravity from the first well to the last well at the end of which there is a tank from which pipelines take the water to the town below. The wells are called kundis whereas the tunnel is called Khooni Bhandara possibly because of the slightly reddish colour of the water in it.
Currently about 0.15 million litres of water per day flows out of the tunnel.
What struck me most was the ingenuity of the Mughals in devising a system that first tapped the rain water by harvesting it and then used an underground tunnel to extract it and take it by gravity to the town. This was a necessity at the time because there were no mechanised pumps to do lift water from the underground aquifer at that time. This tunnel was dug by human labour obviously as there were no machines then and this adds to the uniqueness of the system. Water harvesting is the most sustainable means of water supply. The Asirgarh fort on a high hill nearby too has excellent water harvesting systems for its water supply.