May 11, 2008

Landfills of Mumbai

New people moving into Mumbai will do well to keep track of the landfills. It is not clear how clean the soil over the landfills would be for some time to come. The same caution applies to residences as well as workplaces. Mumbaikars spent more time at work that at home anyway.

There is a science to the landfills.
Landfills are usually lined with several feet of dense clay and then sealed with thick layers of plastic to prevent leaks of hazardous chemicals. The garbage is dumped in rows or piles from 10 to 20 feet high. Bulldozers are used push the garbage into rows and squash large objects. Compactors with 5 foot wide studded rollers are also used to squash the garbage. Squashed garbage takes up less space extending the life of the landfill. Each day, soil, glass, or plastic foam pellets is spread over a landfill to reduce odors and pests. The soil covering also reduces the amount of rainwater that seeps in. Invading rainwater carries water-soluble chemicals out of the garbage to form liquids called leachates. When leachates pool in the bottom of the landfill, they are pumped out, collected and treated. The treated leachate is handled like sewage. The particles, called sludge, are separated from the liquid and burned, or used as fertilizer, or dumped in the ocean or back into the landfill. If the sludge is considered hazardous, it is shipped to a hazardous waste disposal site.


Here are the current large landfills.

Deonar

132 hectare plot is the oldest dumping ground and it receives 4000 tonnes of refuse every day.

Mulund

25 hectares of landfill accepts 600 tonnes of waste each day.

Gorai

1200 tonnes of waste is dumped here each day.

Kanjur Village

141 hectare plot is the newest of the landfills.

Kolshet and Shilphata

These landfills get 1000 tonnes of garbage from Thane civic authority.

Aadharwadi and Telkoswadi

These landfills get 2300 tonnes daily.

Turbhe

Gets the garbage from navi mumbai.