Uranium levels in Delhi’s groundwater third highest in country, shows report

Health experts underline that long-term use of uranium-tainted groundwater can cause kidney damage and chemical toxicity and may raise the risk of cancer-linked effects

The capital city had the third highest share of uranium-contaminated groundwater samples in the country in 2024, with readings above the Bureau of Indian Standards (BIS) limit of 30 parts per billion (ppb) in both pre- and post-monsoon testing, the Central Ground Water Board’s Annual Ground Water Quality Report 2025 shows.

The capital ranked third after Punjab and Haryana, the report said. (HT Archive)

The national comparison is based on 3,754 groundwater samples collected across states and Union territories. In Delhi, 15.66% of samples collected after the monsoon exceeded the safe uranium threshold. In the pre-monsoon period, 13.25% of samples recorded high contamination. The capital ranked third after Punjab and Haryana, the report said.

Health experts underline that long-term use of uranium-tainted groundwater can cause kidney damage and chemical toxicity and may raise the risk of cancer-linked effects. Activists say the contamination is being fuelled by geological factors such as natural uranium-bearing rock and also over-extraction, as depleted aquifers are tapped deeper through borewells.

Nationally, the problem is most severe in Punjab, where 62% of samples breached safe limits in the post-monsoon period, while 53% were contaminated before the monsoon. Other hotspots include Rajasthan, Chandigarh, Chhattisgarh, Rajasthan and Chandigarh, though levels vary.

For Delhi, the findings carry direct risks for neighbourhoods that still rely on tubewells for daily needs, particularly residential colonies not yet covered by the piped-water supply. Water specialists warn that groundwater depletion is forcing wells deeper into rock layers that contain radioactive elements, heightening uranium presence in extracted water.

“The report calls for urgent government intervention to protect public health, including the introduction of scientific treatment methods, along with strict monitoring and periodic testing of tubewell supplies. A Rajya Sabha reply last year showed contamination was at 10%. It is near 15% now and that is alarming,” said water activist Pankaj Singh.

Singh has also flagged the scale in letters to the Delhi LG and chief minister, warning that 450 million litres of water supplied daily by the Delhi Jal Board through 5,500 tubewells and Ranney wells must be urgently tested and monitored. He noted the need for swift, structured quality checks on the 5,500-plus groundwater assets running across the capital.

Haryana too recorded a sharp rise — from 10% contamination before the monsoon to 23.75% after monsoon, though a typo in earlier drafts had marked this incorrectly. Chandigarh, Rajasthan and Chhattisgarh continue to show measurable contamination, activists added.

At an all-India level, 6.71% of samples exceeded uranium limits before the monsoon, rising modestly to 7.91% after the monsoon, indicating a nationwide seasonal uptick. In contrast, contamination remained low or limited in Gujarat, Karnataka, Maharashtra, Tamil Nadu, and in northeastern states such as Nagaland, Mizoram and Manipur, the report said.