Urbanization is taking a place at an alarming pace in India with the Urban population burgeoning to 33.6% in the past decade. The result is an increasing demand for clean and safe water in population-rich urban hubs. Many cities are unable to keep up with the demand as the majority of readily available sources have been exploited. Lack of adequate wastewater treatment infrastructure and the discharge of wastewater directly into surface water-bodies has aggravated the problem.
Currently, there is a large deficit in the wastewater being generated in India and the water that is being treated to make it safe and potable again. According to CPCB report – Status of Sewage Treatment in India, Municipal wastewater generated in the 35 metropolitan cities of India collectively amount to 15,644 Million Litres per Day (MLD) of sewage. However, the sewage treatment capacity is half this number at 8040 MLD (51%). This leads to a precarious surplus of sewage waste being flushed into our water bodies with little to no waste water treatment.
A major crisis can be averted by Decentralized Wastewater Management
Decentralized wastewater management systems in which large volumes of wastewater is treated for different purposes by different community initiatives and public-private partnerships are the only effective way to deal with the potable water crisis. This also reduces the strain on government agencies to take up the entire burden of sewage and water treatment and the only way to resolve the major capacity crisis being faced by Indian cities.
Decentralized wastewater management treats the wastewater of individual houses, apartment blocks or small communities close to their origin instead of at the outlet point. This helps reduce the polluted water flowing through the city and into water bodies. This also prevents contamination due to water seepage that may occur at various points. Several countries such as Japan, Australia, and China have begun to make decentralized wastewater treatment and reuse mandatory.
In India, decentralized wastewater treatment and reuse system have been successfully adopted at Bangalore. The city’s centralized wastewater treatment system has not kept pace with the rampant industrialization and population growth. The total installed sewage treatment capacity was only 58% of the total wastewater being generated and much of the wastewater was dumped into lakes leading to health and environmental crisis.
In 2004, the Karnataka State Pollution Control Board mandated buildings with 50 or more residential units or built-up area more than 5000 m2 to install on-site sewage treatment plans (decentralized wastewater management systems) and reuse most of the treated water.
Nearly 2,000 buildings in Bangalore have installed decentralized sewage treatment plans with an estimated total installed capacity around 110 MLD or 10% of the total wastewater generated in the city. The initiative has helped vastly in reduced wastewater discharge into lakes and the recycled water is being used for toilet flushing, landscaping and gardening reducing the overall water burden on the municipal board.
Effective government policy and public-private partnerships in decentralized water management seem to be the most feasible solution to help fight the urban water crisis in India. Community initiatives can help reverse the harm done by years of exploiting the groundwater table and reduce the water woes being faced in the country.
Advantages of Decentralized Wastewater Management: