77% of Delhi’s Water Supply Unsafe for Human Consumption

77% of Delhi’s Water Supply Unsafe for Human Consumption

A shocking new report has revealed that 77% of the water supplied to Delhi’s residents is unsafe for human consumption, raising urgent concerns about public health and infrastructure failures.

People collect drinking water from a tanker on a hot summer day at Vivekanand camp in New Delhi on May 28.(PTI)

77% of Delhi’s Water Supply Unsafe for Human Consumption

Despite official claims of improvement, independent studies highlight systemic contamination, failing treatment plants, and severe health risks linked to the capital’s drinking water.

Widespread Contamination Raises Red Flags

Delhi Jal Board’s (DJB) official data suggests that less than 5% of the city’s water is contaminated. However, independent tests contradict this claim. A recent survey analyzed groundwater and piped water samples across multiple districts, finding excessive levels of ammonia, nitrates, iron, and fecal bacteria in over three-quarters of tested sources.

Groundwater, which supplements Delhi’s piped water network, has been particularly alarming. A 2023 study of 5,000 tube wells found that 25% contained dangerously high levels of nitrates and heavy metals, exceeding safe drinking limits. In January 2024, ammoniacal nitrogen levels at the Wazirabad water treatment plant spiked to 4.9 mg/l, nearly ten times the safe limit of 0.5 mg/l, forcing temporary shutdowns and water shortages in several parts of the city.

Aging Infrastructure and Failing Treatment Plants

One of the primary reasons for the crisis is the city’s deteriorating water infrastructure. Delhi’s 14,000 km of pipelines are plagued with leaks and cross-contamination from sewage lines. In July 2024, residents of Peeragarhi village reported receiving blue, chemically tainted water due to a broken sewer line contaminating their supply.

Water treatment plants are also struggling to meet safety standards. Audits conducted in August 2024 found severe violations at multiple sewage treatment plants (STPs), with samples showing dangerously high levels of faecal coliform, biochemical oxygen demand (BOD), and phosphates. The Yamuna River, Delhi’s primary water source, remains critically polluted, with BOD levels at Asgarpur reaching 85 mg/l in June 2024—28 times the permissible limit.

Delhi’s overburdened treatment plants, some dating back to 1935, are operating 40 million gallons per day (MGD) over capacity. The Chandrawal and Wazirabad plants have been particularly affected, with residents in areas like Sadar Bazar and Karol Bagh receiving discolored and foul-smelling water.

Public Health at Risk: Rise in Waterborne Diseases

Unsafe drinking water has led to a surge in waterborne illnesses. According to government data, reported cases of diarrhea rose by 35% in the past year, from 15,152 cases in 2022-23 to 20,393 in 2023-24. A 2024 survey revealed that 10.6% of children under five in Delhi suffer from diarrhea, a direct result of consuming contaminated water.

The presence of heavy metals such as lead and mercury in tap water poses long-term health risks, including neurological disorders, kidney damage, and increased cancer rates. Medical experts warn that continuous exposure to such contaminants weakens immunity and heightens vulnerability to infections.

Official Responses and Public Dissatisfaction

Despite DJB’s assurances that Delhi’s water quality has improved, public dissatisfaction remains high. A May 2024 survey conducted by LocalCircles found that 39% of Delhi residents were unhappy with their tap water quality, citing frequent complaints of murkiness, odor, and visible sediments.

In response to the crisis, the Delhi government launched the “Walk the Line” initiative in January 2025, deploying engineers to inspect and repair leaking pipelines. However, experts argue that these measures are reactive rather than preventive and fail to address the root causes of the crisis—industrial pollution, sewage mismanagement, and an aging water distribution network.

A Call for Urgent Action

Water experts emphasize the need for immediate interventions, including upgrading treatment plants, stricter pollution controls, and improved sewage management. Environmentalists have called for increased government transparency, demanding real-time public access to water quality reports.

The Supreme Court is currently hearing petitions for additional water allocations from neighboring states, including Haryana and Himachal Pradesh. Meanwhile, Delhi’s residents continue to rely on expensive bottled water or household filtration systems to ensure their drinking water is safe.

As the city grapples with one of its worst water crises in recent history, the question remains—how long can Delhi’s residents wait for a sustainable solution?