Yamuna to be freed from polluted water

By Pramod Kumar

New Delhi, Aug. 6: The filthy Yamuna will now be spared from the "treated effluent water" also. The government is considering to divert the treated effluent water to major thermal power stations in New Delhi to cool the plant. Besides, all sewage treatment plants and common effluent treatment plants have also been asked for optimum utilisation of their facilities in the capital. The Centre for Science and Environment has been asked by the Delhi government to prepare comprehensive "action plan" in this regard.

The Delhi chief secretary S. Regunathan called a meeting of senior officials of all concerned departments on Friday and discussed the matter at length. The meeting was attended by representatives of the CSE also.

The chief secretary also instructed all concerned departments to ensure optimum utilisation of sewage treatment plants and sewage effluent treatment plants in the capital. According to sources, the government is also considering to stop the discharge of effluents from six major drains in the capital.

The Yamuna enters Delhi at Palla village 15 km upstream of Wazirabad barrage, which acts as a reservoir for Delhi. Delhi generates 1,900 million litre per day (mld) of sewage, against an installed waste water treatment capacity of 1,270 mld. Thus, 630 mld of untreated and a significant amount of partially treated sewage enters the river every day. Sources informed the Wazirabad barrage lets out very little water into the river. In summer months especially, the only flow downstream of Wazirabad is of industrial and sewage effluents. Lesser discharge means lesser river flow and thus greater levels of pollution. From the Okhla barrage, which is the exit point for the river in Delhi, the Agra canal branches out from Yamuna.

During the dry months, almost no water is released from this barrage to downstream Yamuna. Instead, discharges from the Shahadara drain join the river downstream of the barrage, bringing effluents from East Delhi and Noida into the river. This is the second largest polluter of the river after the Najafgarh drain.

Experts believe that the main problem lies in undetected and untreated pesticide residues. Waterworks officials in Delhi and Agra point out that pesticide traces cannot be removed with conventional treatment.

The river has a dilution requirement of 75 per cent, which implies that for every 100 litres of waste water, 75 litres of freshwater is required. Scientists state that with the flow of water, pollutants (especially organic pollutants) degrade to a large extent. But at every step, this purified water is abstracted, and larger loads of pollution make their way into the river