Company Name : Nepra Environmental Solutions Pvt.Ltd-bansi Source : http://www.business-standard.com/india/news/mumbais-mithi-may-gasp-for-air-despite-oxygen/390710/

Mohit Vaz has been traveling in Mumbai’s local trains for over 20 years. He boards the train at Church gate and alights at Vasai. Regardless of whether he’s reading a newspaper or taking a nap, Vaz routinely whips out his handkerchief when the train approaches the Bandra station and covers his nose. “I can smell the Mahim creek from a distance. The stench can be unbearable at times,” rues Vaz.

The creek is where Mumbai’s little-known river, the Mithi, empties itself into the Arabian Sea, carrying millions of tones of waste. Little known to Vaz, the Mumbai Metropolitan Region Development Authority (MMRDA) has completed a pilot which attempts to breathe life once again into the Mithi. Since December 2009, oxygen is being pumped into water along a kilometer-long stretch of the river. The results of this experiment are expected within the next two weeks. “The National Environmental Engineering Research Institute is evaluating the results, after which MMRDA will decide on whether the pilot should be extended to other parts or not,” said MMRDA Joint Project Director Dilip Kawathkar. The 18-km river runs from Vihar, Powai to Mahim Causeway, and untreated waste is dumped into it through 43 drains along the stretch. This lowers the level of dissolved oxygen in the river.

Oxygen is essential for fish which eat mosquito larvae. The infusion of oxygen is also expected to reduce the stench emanating from the river. “Our aim is to make the 6-km stretch (part of the 18-km river which is with MMRDA; the rest is with the Bombay Municipal Corporation) an eco-friendly tourist spot,” said Kawathkar. MMRDA has engaged the services of US-based Environmental Consulting Technology Inc which has rented two units of an oxygen-infusion device called DynamOx. It oxidizes about 8 to 10 gallons of water per minute, and runs round the clock. The two units are estimated to cost around Rs 1.5 crore.

This is a part of the Rs 100-crore Mithi River Development Work which includes deepening and widening the river, and construction of a wall to protect the banks of the river from encroachment and waste disposal. “The Vakola nullah has been widened one-and-a-half times. The de-silting work is over, and a wall is being constructed as recommended by the Central Water Power Research Station (Pune) and Indian Institute of Technology Bombay,” said Kawathkar. The Mithi is also getting a facelift. The Rs 9.80-crore project is expected to offer facilities like jogging and walking tracks, meditation and acupressure therapy platforms on the banks of the river. It will have coconut, betel nut, ficus benjamina and plumeria Alba trees, according to MMRDA Metropolitan Commissioner Ratnakar Gaikwad. Environmental agencies and activists are not enthused.

For one, they said, that instead of such “cosmetic solutions”, the government should spend time tackling the sewage problem which is the real headache of most rivers. The Mithi is a confluence of tail water discharges of the Powai and Vihar lakes. It originates in Powai and flows through residential and industrial complexes of Powai, Saki Naka, Kurla and Mahim. It is treated like an open drain by Mumbaikars who discharge raw sewage, industrial waste and garbage unchecked. Besides this, illegal washing of oily drums and discharge of unauthorized hazardous waste are also carried out along the course of this river. This has choked the Mithi. Around 800 million liters of sewage in channeled in the Mithi daily, according to Girish Raut, an advocate and environmental activist from Mumbai.

“Authorities like MMRDA have not understood what a river means. It's an ecosystem which needs to be preserved and not misused under the garb of development,” he said. “Choking of the river over the years has resulted in floods in Mumbai city. We have not learnt any lesson." "The money the government is spending on pumping oxygen should rather be spent on managing the city's waste which not only harms rivers but also increases health costs," Centre for Science and Environment Associate Director Chandra Bhushan added. As a thumb rule, treatment of waste is around five times more expensive than getting water.

Cities are sourcing water from further and further away, and it costs them money to pump besides high losses in water transportation (roughly 20 to 50 per cent). Moreover, the untreated waste goes into water of other rivers and the sea. When cities can't clean their rivers, they look for new sources. For instance, Chennai which sources water from the Veeranam lake (235 km) is now planning to go further to 300 Km (Veeranam extension project) while Delhi is sourcing water from the Tehri dam which is almost 500 kilometers away. Mumbai, which sources water from the Bhatsa, Tansa and Vaitarna lakes (around 100 km distance), is also looking for new far-off sources.