New Delhi: In some areas of Delhi, groundwater was found "unfit" for human consumption, the Economic Survey Report of Delhi 2014-15 has said while raising "serious concern" over depleting groundwater level.
"The quality of underground water is deteriorating in several places. It has been found to be unfit for human consumption. The salinity of ground water is increasing in South-West and North-West Delhi. In some areas of Shahdara and Kanjhawala, nitrate content has been found to be more than 1000 mg/litre.
"Fluoride and chemical concentrations, more than prescribed limits, have also been found in ground water at various locations in Delhi," According to the Economic Survey Report of Delhi, 2014-15, tabled in the Assembly on Wednesday.
To tackle these problems, the Central Ground Water Board has taken steps to regulate the number of tube-wells being commissioned in Delhi.
As on March 2014, Delhi Jal Board has 3,961 functional tube wells and 14 ranney wells.
The flood plains downstream of Wazirabad and the area adjacent to Najafgarh Lake are being explored for extraction of water on sustainable basis. Pre-feasibility studies for ground water recharge through the abandoned Bhatti Mines and Canal system in the North Western region of Delhi have also been taken.
Deepening of old lakes and other water bodies, preserving and developing the forest area in Delhi, construction of check dams at Asola Wild Life Sanctuary and plantation of trees, are some of the steps being taken to improve ground water resources by the department concerned.
Also, Delhi has a network of about 11,350 kilometres of water supply mains, of which, a significant portion is as old as 40 to 50 years and prone to higher leakage losses.
"Normally, water losses are calculated by water billed or consumed subtracted from the water produced. In the case of Delhi, water billed or consumed and leakage losses there from cannot be calculated exactly as a majority of houses do not have working metres," the report said.
According to estimates of Delhi Jal Board (DJB), the total distribution losses are in the order of 40 per cent of the total water supplied. These are quite high as compared to 10-20 per cent in the developing countries.
The distribution losses include losses due to leaking pipes and theft of water through unauthorised connections.
"DJB has taken several steps to minimize leakage losses. To address this problem, a leak detection and investigation (LDI) cell was set up. The Board has replaced about 1,200 km length of the old, damaged and leaking water mains during the last five years. As a result of these initiatives, the Board expects to bring down the distribution losses to 20 per cent level in the near future," the report said.
Delhi Jal Board has formulated a programme for recycling of backwash water in four major water treatment plants at Haiderpur, Bhagirathi, Chandrawal and Wazirabad. The work for commissioning of recycling plant at Haiderpur, Bhagirathi, Wazirabad units has been completed. About 45 MGD water supplies will be available without any additional raw water from these four plants.
According to the survey report, sewage treatment capacity of DJB increased from 402.40 MGD in March 31, 2001 to 613.72 MGD in March 31, 2015.
About 81.3 per cent households of Delhi now have access to piped water supply, stated the Economic Survey report of Delhi 2014-15.
Water production during summer season is being maintained at 835 MGD per day consistently. Water is supplied to about 18 million population of Delhi through a water supply network comprising 14,000 km long pipelines and more than 107 underground reservoirs (UGRs), the survey said.
As many as 407 new water tankers with stainless steel containers and fitted with GPS have been engaged on long duration contact for improving the water tanker supply delivery system in the city.
Water supply distribution network has been developed in a planned manner to cover both planned and unplanned areas. Supply is made available to 903 unauthorised colonies. Filter water supply is also provided to another 50 unauthorised colonies, covering a population of about 2 lakh.
