Bengal, with its twin water threats, heightens watch after Indore crisis

The crisis over contaminated water in Madhya Pradesh’s Indore, which has left at least six dead and hundreds hospitalised, has rung the alarm bells in other states too. In West Bengal, several civic bodies have heightened their watch over drinking water as the state is known to grapple with both groundwater and surface water contamination.

The Kolkata Municipal Corporation (KMC) has put the city’s water installations on high alert and ordered stricter laboratory testing of raw water before it is sent to treatment plants in Palta, Garden Reach, Dhapa, Jorabagan and Watgunge.

Officials say special laboratory tests will be conducted at all major treatment facilities to ensure that purity standards are not compromised.

High levels of arsenic in groundwater

Official data and recent government actions reconfirm that West Bengal is confronting twin water crises. The recent nationwide monitoring by the Central Ground Water Board (CGWB) indicated that both groundwater and surface water in West Bengal show contamination.

Also read: Indore water contamination: 203 still in hospitals, says Collector

The Annual Groundwater Quality Report 2025 showed that in the pre-monsoon phase, about 19.5 per cent of samples from West Bengal exceeded the arsenic limit of 10 ppb (parts per billion), and in the post-monsoon phase, around 15.7 per cent of samples were above the threshold, highlighting arsenic contamination.

The former report, which analysed nearly 16,000 locations, including more than 900 in West Bengal, found that about 8.8 per cent of the samples exceeded the permissible arsenic limit, while 35.2 per cent indicated iron above safety thresholds. Other parameters, such as nitrate and fluoride, too surfaced above the acceptable limits in various pockets of the state.

Decline in water table

The presence of arsenic, a highly toxic element, in groundwater remains a persistent and well documented threat in the state.

Also read: Indore water contamination: Why 'cleanest city' model is under scanner

Decades-long research published in peer-reviewed journals and government reports indicates that nearly half of sample tube wells across 19 districts in West Bengal contain arsenic above the World Health Organization (WHO) guidance value (10 PPB), with an estimated 2.6 crore people potentially at the risk of consuming the contaminated water.

Decline in groundwater levels in several pockets of the state, including Kolkata and adjoining districts, further heighten quality concerns.

Urban demand outpaces replenishment

Data from 2017 to 2021 show that Kolkata’s water table dropped by more than 2 metres, with parts of South 24-Parganas experiencing even steeper decline of up to 2.5 metres over the same five-year period. In many areas of the city, the drawdown is even more pronounced.

According to KMC sources, two decades ago, the city’s water table ranged between 7 and 10 metres below ground level. Today, it lies at 14 to 16 metres in many areas, with some records showing levels as low as 8 to 10 metres around Garia and 9 to 11 metres in Bansdroni, two neighbourhoods that have seen a significant surge in high-rise construction.

Environmental scientist Abhijit Chattopadhyay said, “Without integrated recharge measures, Kolkata’s aquifers face irreversible stress as urban demand outpaces natural replenishment.”

Also read: Indore contamination deaths: Poison, not water, says Rahul Gandhi

Industrial pollutants and surface water contamination

Beyond groundwater contaminants, industrial pollutants and heavy metals are also increasingly detected near manufacturing belts.

A National Mission for Clean Ganga (NMCG) report submitted to the National Green Tribunal (NGT) in late 2025 highlighted that numerous industrial units in the Jalan Industrial Complex, Sankrail Industrial Park, and Dhulagari village have been linked to untreated effluent flowing into the Barjola Canal, which ultimately drains into the Hooghly river.

Water quality tests along the Hooghly and linked canals have repeatedly shown faecal coliform bacteria count above permissible thresholds set by the WHO and Indian standards, the report said.

Seeking detailed data on bacteria in the stretch of Ganga (Hooghly) in West Bengal, the NGT recently directed the Central Pollution Control Board to share E. coli and coliform counts and asked state authorities to provide their own reports, amid growing worries about sewage pollution, according to the sources in the West Bengal Pollution Control Board.

Stringent measures to be taken

Jolted by the Indore tragedy, KMC will now conduct special laboratory tests at all major treatment facilities to ensure that the purity standards are not compromised. The KMC has also introduced measures to address water stress and reduce contamination risks.

Also read: Indore water contamination: Authorities yet to pinpoint source as probe expands

A senior official from the KMC water supply department said it is also crucial to check the water quality at booster pumping stations, since water can get contaminated while travelling through pipelines.

The official added that if any quality issues are found, measures such as raising the level of residual chlorine would be implemented before the water reaches households.

Eye on vulnerable zones

The official highlighted areas like the Kankurgachhi-Maniktala belt, Park Circus, Bhowanipore, and the Tollygunge-Jadavpur belt for closer monitoring as they were prone to contamination earlier. He also noted that tube-well zones would be closely watched, as ensuring the quality of groundwater can sometimes be challenging.

Swapan Samaddar, KMC’s environment mayoral councillor, said the city has begun implementing measures and is working to “minimise groundwater extraction wherever possible”.

A state environment department directive requires multi-storied residential buildings with more than 20,000 sq m of built-up area to install sewage treatment and wastewater reuse systems, and to submit monthly reports on treated volumes and their uses, such as gardening and cleaning.

Heightened watch in districts

Other civic bodies have also stepped up action following the Indore incident. Abhay Das, chairman of Uluberia Municipality in Howrah, said engineers are inspecting supply lines before distribution and increasing surveillance of water treatment and delivery systems.

Pintu Mahato, head of Baidyabati Municipality in Hooghly, added, “After seeing the deaths from contaminated water in Madhya Pradesh, we are genuinely concerned. We test the water before it reaches homes and send samples every 15 days to a private lab in Barrackpore.”

Also read: Chennai’s drinking water crisis mirrors deeper urban failures across India

In Jalpaiguri, authorities recently launched a Rs 150-crore AMRUT drinking water project aimed at supplying treated water from the Teesta River to homes across the municipality.

Fear after Indore contamination

However, following the Indore incident, the launch has raised concerns, with residents and local officials warning against drinking the water until the treatment and distribution systems are fully operational.

A local resident, Kablu Hajra, said although household connections exist, “the water comes but we are told not to use it,” adding, “we want pure drinking water delivered to our homes soon.”

Municipal chairperson Saikat Chatterjee said piped potable supply to every home was expected only by mid-February.

Public Health and Engineering Minister Pulak Ray, however, asserted that “West Bengal’s potable water supply is carefully managed and regularly tested” and that “there is no lapse in these procedures”.