SEWAGE MANAGEMENT IN DELHI

The population growth and rapid urbanisation has led to immense pressure on basic amenities such as water supply, wastewater collection and treatment. The potable water generation by concerned agency in the city is 2621.85 MLD, which is supplied to the city after accomodating 20.5% of distribution losses.

The Conventional method for estimation of generated wastewater is, derived at 80% of the water supplied. However, this may not be realistic in the areas like Delhi, where huge amount of ground water is simultaneously extracted and utilised. Therefore, all the major drains, sewage treatment plants have been monitored to derive the actual wastewater generation in the National Capital Territory - Delhi. This study reveals that 2546.88 MLD of sewage is generated in Delhi and of which, only 885.3 MLD of sewage is collected through sewerage network for treatment and rest 1661.84 MLD of sewage flow in storm water drains, thus, making these open sewers, and in turn causes foul smell and ground water contamination all along the drain and ultimately polluting disposal sink i.e. sacred river Yamuna. The Delhi has 1153.16 MLD of sewage treatment capacity, whereas, only 885.3 MLD is collected through sewerage network and treated in treatment plants.

Within this backdrop, it is to estimated that at about 1030 MLD of water is extracted in addition to ground water extraction of 306 MLD by the Delhi Jal Board. This huge extraction of ground water may be the sole cause for increased salinity and contamination of aquifer. The effort have been made to find the cumulative pollution load addition to river Yamuna (23 kms stretch from Wazirabad Barrage to Okhla Barrage) at various points by the major drains carrying wastewater from National Capital Territory of Delhi.