Capital groundwater found contaminated with uranium, lead, nitrates, fluoride: CGWB report

New Delhi: A new assessment by the Central Ground Water Board (CGWB) has raised serious concerns about the safety of Delhi’s groundwater, revealing traces of uranium and several other toxic substances in samples collected across the city.

The findings place the national capital among the higher-risk regions in north India, following Punjab and Haryana, where uranium contamination has been a longstanding issue.

The report shows that uranium levels surpassed the permissible limit of 30 parts per billion (ppb) in roughly 13–16 per cent of the samples tested from Delhi, drawn from around 83–86 locations. This means nearly one out of every seven wells checked contained uranium concentrations above safe limits. Scientists warn that continuous consumption of uranium-laden water may affect kidney function, weaken bones and, over extended exposure, elevate the probability of certain cancers.

But uranium is only part of the problem. The CGWB’s analysis paints a wider picture of chemically stressed aquifers beneath Delhi.

Elevated nitrate concentrations were found in multiple wells, a trend the Board attributes to fertiliser runoff, unregulated waste dumping and sewage seepage, all of which intensify in densely populated and peri-urban belts.

High nitrate levels are particularly dangerous for infants, increasing the risk of “blue baby syndrome”, a condition where blood loses its ability to carry sufficient oxygen.

Fluoride, another recurring contaminant in Delhi’s groundwater, was also detected above safe concentrations in

several pockets.

The report notes that fluoride intrusion often has natural origins linked to local rock formations and mineral interactions underground, but can be aggravated by industrial discharge and poor waste management.

Perhaps the most alarming finding is Delhi’s position at the top of the list for lead contamination among the surveyed regions.

Nearly 9.3 per cent of the samples exceeded the permissible limits for lead, a heavy metal for which experts agree there is no safe level of human exposure. Lead poisoning, particularly in children, can impair brain development, damage organs such as the kidneys and raise blood pressure

over time.

The report underscores the urgent need for improved groundwater monitoring, stricter pollution controls and stronger urban planning to prevent further degradation of the city’s already strained aquifers.