Water treatment by DJB up by 13% in last decade
A large portion of the increase came from groundwater extraction, even as Delhi plans a rapid expansion of its tube well infrastructure.
The water treatment capacity of the Delhi Jal Board has seen an increase of 13% over the past decade to 943 million gallons per day in 2022 from 906 MGD in 2014, according to the 2022-23 economic survey released by finance minister Kailash Gahlot during the budget session on Monday.
A large portion of the increase came from groundwater extraction, even as Delhi plans a rapid expansion of its tube well infrastructure. While the water utility extracted 80 MGD of groundwater in 2014, it has currently risen to 117 MGD to meet growing demands. The jump is also reflected in the number of water extraction points across the city, which now stands at 4,991 tube wells and 11 ranney wells. Having added around 500 such units over the past year, the Delhi Jal Board plans to operationalize another 587 tube wells in the coming days.
The floodplains of the Yamuna river and the area adjacent to the Najafgarh lake are being explored for extraction of water, the survey said. Of the 587 new water extraction points, most are expected to come up near water treatment plants, sewage treatment plants, floodplains and water bodies.
The distribution of the upcoming units shows that 150 tube wells will be set up along the periphery of Bhalswa lake, another 150 in Nilothi and Najafgarh, 85 tube wells each around Rohini and Okhla sewage treatment plant, 45 around Dwarka water treatment plant, 35 in Chilla and less than 10 units near the Barapullah and Akshardham belt.
Diwan Singh, environmental activist who organised the Yamuna Satyagrah for rejuvenating the river and other water bodies in the city, said that while the water mining within justifiable limits in floodplains is sustainable, DJB should ensure that the ecology of these areas is not impacted due to large scale water extraction. “If too much water is extracted, the saline layers of water rises above and damages the overall aquifer in the region. The quality of water extracted should be constantly monitored. In my opinion, using the Reverse Osmosis plants for treating saline water may not be economically feasible but if the government wishes to try this method, they should go ahead.”
Singh opposed the idea of using the treated wastewater for recharging groundwater and re-extracting the water for domestic use by citing the possibilities of contamination of ground water.
Delhi’s dependence on groundwater has grown in order meet “increasing demand of water, and the limited surface water sources and frequent pollution in raw water sources at Wazirabad,” the annual report admitted. “The deterioration of groundwater quality is still being observed and all efforts to stop further deterioration are being taken,” it said.
The survey also revised the estimated water demand of the capital city. Delhi would require 1,260 MGD of water for its projected population of 21 million people, it said.
About 93% of households of Delhi have access to piped water supply and average water production during summer season is being maintained at 956 MGD, the survey said. The water ultility, however, continued to see massive distribution losses at around 58%. The DJB is installing flow metres and repairing old lines to reduce the losses. DJB has aslo set up a leak detection and investigation cell to minimize leakages by replaced 1,432km of pipelines over the past five years.
A DJB official said that the water is being extracted only in the areas where the groundwater levels are very high and conditions near these sites will ensure that the ground water is constantly replenished through water bodies and river Yamuna.