Park may come up at Gorai dumpyard

Anil Singh I TNN

Mumbai: The BMC hopes that it will earn a total of Rs 73 crore from the closure of Gorai dumping ground and Rs 26 crore earned from carbon credit is essentially for the capture and combustion of methane gas emanating from the dump which results in a substantial reduction of greenhouse emissions.

As heartening as the cashfrom-trash bargain, however, is the transformation of the 50-acre dumping ground, more than twice the size of the Oval Maidan, from a stinking mountain of garbage into a contoured, landscaped hill. The initial plan for a golf course here seems too optimistic but it can surely serve as a public park after three to fours years, by which time the dump will have reached its final shape.

Garbage was being dumped at this plot adjoining the Gorai creek since 1972. Thirty-five years later when the dump was closed in December 2007, it was receiving 2,200 tonnes of refuse a day, and the 2.3 million tonnes of accumulated waste had stacked up to 32 metres, as high as an 11-storey building. By this time, the urban sprawl had reached the edges of the dump and pressure from local residents in the form of agitations and lawsuits played its part in expediting its closure.

The consultants appointed by the municipal corporation, Infrastructure Leasing and Financial Services Ltd (IL & FS), recommended scientific closure of the dump as it had reached saturation point. The cost of the project, the first of its kind in the country, is Rs 62 crore, which includes post-closure maintenance of 15 years.

“The Gorai experiment succeeded because of proper project development and structuring coupled with unstinted support from the civic authorities,’’ said Chetan Zaveri, vice-president of the environment division of IL & FS, which worked out the carbon advance transaction.

Today, not only is the dumping ground unrecognisable from what it was two years ago, the stench from it has also vanished. In fact, standing atop the 26-metre high plateau on the mound, this correspondent got a breathtaking view of the lazily flowing creek, the lush green mangroves and the soaring Vipassana pagoda in the backdrop.

The contractors, United Phosphorus Ltd (UPL) and their joint-venture partners, Vanderwiel Strotgas BV, basically flattened the top of the garbage mound and created gentler slopes after which it was sealed in three layers of dense plastic at varying depths. The plastic sheets prevent the seepage of rainwater and the formation of leachate, a cocktail of highly toxic compounds.

Over the topmost plastic sheet is a two-feet layer of construction rubble topped by one feet of earth which supports foliage in the form of grass, shrubs and small trees with shallow roots.

“An intricate subterranean network of pipes collect the gases, 70% of which is methane, from the rotting garbage and relays it through 40 wells to a chimney where it is flared,’’ explained Sundar Balasubramanian, UPL’s vicepresident, Environment Business. One tonne of methane is equivalent to 21 tonnes of carbon dioxide in terms of global warming potential.

To prevent the leachate from seeping into the creek, a seven-metre deep concrete wall has been built into the edges of the dump. Whatever leachate is formed because of the existing moisture is channelised into a processing tank to neutralise its toxicity.

“Earlier, the mangroves ringing the dump had turned brown because of the water pollution but now they have regenerated,’’ said P S Awate, executive engineer of the civic corporation’s solid waste department, pointing to the dark green foliage on the fringes of the dump.

What are carbon credits
Emissions of carbon dioxide and other greenhouse gases from industrial processes have contributed in a big way to global warming. To counter this and get countries to reduce emissions, the Clean Development Mechanism (CDM), provided for by the Kyoto Protocol, allows a developed country to take up a greenhouse gas reduction project activity in a developing country where the cost of such projects is usually much lower. The developed country will get carbon credits for meeting its emission reduction targets, while the developing country will receive the capital and clean technology to implement the project. One carbon credit equals one tonne of carbon, and these credits are bought and sold on international carbon credit exchanges.