Waste water makes a turnaround

MADURAI

For many residents of Madurai, waste water is usually an afterthought that is ignored. Stigma associated with waste water presents itself in the most unlikely ways as it is largely considered unhygienic and unfit for any use.

According to S. Praveen Kumar, Project Executive, Water Knowledge Centre, Tata-Dhan Academy, about 80% of the set 135 litres (per person per day) still goes waste. This standard has been set by the Bureau of Indian Standards 1172: 1993, reaffirmed in 1998. “With reinforcement, some industries in Madurai are making the shift and treating their waste water. In households, people still consider that waste water must be thrown away,” says architect RM. Valliappan.

Some residents however, are paving the way and forging a path towards change. S. Rajendran, a resident of Ram Nagar and a Professor of Botany, has created a water pipe with a biosand filter to sort his waste water from the bathroom and kitchen. This filter has gravels of various sizes – ranging from pebbles to charcoal – in order to clear any and all contamination. This biosand filter can be made or purchased from foundations like DHAN Foundation for about ₹3,500.

While high density elements (like sand) settle to the ground, the ones with low density (like detergent waste) float up. To further purify particles with medium density, a bio-coagulant is added. This bio-coagulant sticks to the particles and settles to the ground, adds the professor. His sprawling terrace garden has over seven varieties of spinach, radish, mint leaves, pumpkins and drumsticks too. He has a vast number of ‘oxygen bombs’ or evergreen succulents like aloe vera. “We also use waste water for a biogas plant I have created,” he adds.

Others like A. Rathinaprakash Ashley, a resident of S.S. Colony, have simpler solutions. This retired teacher says that though his house has an underground drainage system (UGD), he prefers to divert water from the bath area and kitchen to a mango tree in his front yard. “The water we use for washing clothes and vessels goes to the yard to wet the soil where we have a kitchen garden. We also recycle the water used for washing cars, brushing and washing our face,” he says.

Mr. Ashley says that his family has been practising waste water management for over 15 years now. A simple diversion from the bathroom pipe by laying a connecting pipe has made all the difference, he says. It hardly cost him anything and the soil is refreshed during summer months.

Similarly, R. Yoganathan, a resident of K.K. Nagar, says that he too uses water from the kitchen to water his small garden. Excess waste from the bathroom is diverted to the ground for recharge.

In Madurai, waste water from UGD is usually treated at Sakkimangalam and Avaniapuram waste water treatment plants which have the capacity to treat 125 mld (million litres per day) and 45 mld respectively. “The system is well designed and is set to last for more than 20 years but is not optimally used,” says Mr. Praveen Kumar. Only 25 mld of waste water is treated due to poor underground drainage system connectivity. Residents in most of the added wards of Madurai Corporation do not have a UDG system.

With the introduction of simple and affordable water management techniques, residents are looking to process and reap the benefits of waste water.

Founder of Rainstock K. Sakthivel says that basic treatment can be done for waste water from the bath and kitchen areas. “Plants like Canna indica can be planted in a garden-like set up to ingest the biological waste whereas gravel and sand filtration can be used to clear physical contamination,” he says. Waste water has a low level of totally dissolved solids that can be treated easily, he says.

People are still resistant to the idea of treating waste water but the general enthusiasm is picking up, he adds.