DJB to install 80MGD RO plants in areas with saline groundwater: Satyendar Jain
The state water utility plans to install reverse osmosis (RO) plants in areas where groundwater is unusable due to high salinity and levels of total dissolved solids (TDS), said senior officials of the Delhi Jal Board (DJB) after a meeting with water minister Satyendar Jain on Thursday.
Jain said the government will install RO plants with a total capacity of 80mgd (million gallons per day) or 363mld (million litres per day) within a year.
In the first phase, the water utility will install these plants in areas like Okhla, Dwarka, Nilothi-Nangloi, Chilla and Najafgarh. The government estimates that around 725,000 households may benefit from this project.
A senior DJB official explained that the agency is targeting areas with surplus groundwater, but which is unfit for use.
“For instance, water in the Najafgarh area is available at a depth of 2-3 metres, but is extremely saline. Raw water will be supplied to these RO plants using sub-surface resources and purified water will then be supplied to the households,” the official said.
The Delhi government said it will use RO systems that will have 80% water recovery rate, unlike typical systems, which waste a lot of water during the purification process.
The Central Ground Water Board (CGWB) estimates that the city has around 22 lakh million gallonsof saline, and hence unusable, groundwater.
“This can be converted to drinking water after RO treatment and can be used to augment the DJB’s existing water supply. Areas for the project will be selected in such a way that the existing pipeline system can be used, which will save the utility money on laying pipelines,” DJB said in an official statement.
DJB said private investors will bear a major share of the cost to set up the RO plants and the water utility will then buy clean drinking water from them at a fixed rate.
Jain said the DJB will shortlist RO systems available with at least an 80% recovery rate. “Based on initial studies done by DJB officials, the cost of water, in this case, will be equal to the existing cost of water treatment through conventional methods,” Jain said.
The minister said that one small RO plant will be installed for every 500 households and more than one RO plant will be provided in areas where the population is more than 2,000.
DJB currently supplies the city with 4,230mld of water, against a demand of 5,130mld. If the RO project is successful, officials estimate that this shortfall will drop from 900mld currently, to 540mld.