A recent report by the Central Ground Water Authority (CGWA) has highlighted concerning levels of salinity in Delhi’s groundwater. According to the data, more than one in four water samples from the city exhibit high electric conductivity (EC), indicating significant salt content. The findings place Delhi second only to Rajasthan, where nearly 30% of water samples were found to be saline, a TOI report stated.
Saline Water in Delhi Exceeds National Average
The report, submitted to the National Green Tribunal on September 10, noted that the national average for electric conductivity in groundwater stands at 6%. In contrast, over 25% of the water samples from Delhi recorded EC levels exceeding the threshold of 3,000 micro siemens per centimetre. The acceptable EC range for groundwater is between 750 and 3,000 units at 25 degrees Celsius.
Top Areas Affected by High Salinity
The CGWA analysis, based on 95 samples collected during the National Hydrological Survey for 2022-23, found that 24 samples from districts across Delhi had EC levels above the permissible limit. Areas with the highest EC levels were Barwala in Rohini (9,623 units), Sandesh Vihar in Pitampura (8,679 units), and Tagore Garden (7,417 units). Other regions, including Najafgarh, Sultanpur Dabas, Chhawla, and Singhu village, also exhibited alarming salinity ..
Health Risks from High Salinity
According to the Bureau of Indian Standards, drinking water should ideally have total dissolved solids (TDS) limited to 500 mg/L, which translates to an EC of around 750 micro siemens per centimetre. In situations where no alternative water sources are available, the permissible limit may be raised to a TDS of 2,000 mg/L or an EC of 3,000 units. However, water with TDS levels exceeding 2,000 mg/L poses health risks, including kidney-related illnesses.
Groundwater Salinity: Influencing Factors
The report emphasized that electric conductivity is a reliable measure of ion content in water, often directly related to TDS. “Salinity is the saltiness or dissolved salt content of a water body. Salt content is an important factor in water use,” the report stated. It further explained that salinity levels in groundwater vary based on factors such as the type of aquifer, mineral solubility, and the area’s climate and rainfall. The permeability o ..
