Major Causes of Pollution in Ganga River
The dead animals, trees, plants and other organic material flow with the river and settle down in the reservoirs made by hydropower projects. They begin to ferment. Initially they use up the oxygen available in the water and emit carbon dioxide (CO2). But when the oxygen supply is finished, they decompose into Methane (CH4) gas which is more harmful than carbon dioxide.
A Study of Ganga River Pollution Project
The National Environment Engineering Research Institute based at Nagpur has studied the emissions from Tehri Reservoir. They say: “The greenhouse gases, viz. CO2 and CH4 emissions are expected to be more due to decomposition of submerged vegetation in the reservoir and incoming organic matters received through storm waters. The emission levels of carbon dioxide and methane from reservoir were 2550 and 24 milligram per meter square” per day respectively.” (NEERI report is available here Page 15, Para 5). It is clear that the water at the bottom of the Tehri Reservoir is dead. It does not have any oxygen. Fishes cannot thrive in this dead water, when it is released from the dam after generation of electricity
According to a report by the International Rivers Network, greenhouse gas emission from large Hydropower projects in Brazil, the total emissions of CO2 and CH4 are more than 2 kg per kWh of electricity generated (Report available here – table 1). On the other hand these emissions are only 0.95 kg from thermal plants (report attached for reference – page 8). Therefore, large hydro projects add more to carbon emissions than thermal plants. They are dirtier, not cleaner.
How Ganga cleaning will be fruitful when the Government is building large dams like Lakhwar, Vyasi and Pancheshwar on the tributaries of the Ganga?