More than half of the groundwater samples collected from borewells in Indore’s Bhagirathpura locality have tested positive for Escherichia coli (E. coli), officials said on Monday, underscoring the scale of a public health emergency that has already claimed at least 10 lives and sickened thousands. The findings come a day after the Madhya Pradesh government formally declared an epidemic of waterborne diseases in the area, enabling the administration to invoke emergency protocols to contain the spread.

District collector Shivam Verma said faecal coliform contamination was detected in 35 of the 69 groundwater samples drawn from borewells across Bhagirathpura, a densely populated residential neighbourhood. The locality has around 514 borewells, of which nearly 400 are located within private homes and are commonly used for drinking water and domestic purposes. In many households, borewell water is used alongside piped water supplied through the Narmada pipeline, complicating efforts to trace the precise source of infection.

The crisis burst into public view on December 29, when three people from Bhagirathpura died after falling ill with severe gastrointestinal symptoms. Over the following days, hospitals in Indore began reporting a sharp rise in cases of acute diarrhoeal disease, dehydration and sepsis. Laboratory tests conducted on water samples later revealed that the tap water supplied to the area contained a dangerous mix of pathogens. Officials aware of the findings said the samples tested positive not only for E. coli, but also for Salmonella and Vibrio cholerae bacteria, along with the presence of viruses, fungi and protozoa. This combination led to polymicrobial infections in patients, many of whom developed multi-organ failure and septic shock.

As the scale of the outbreak became clear, authorities declared an epidemic on Sunday to ensure that containment measures could be enforced swiftly. The administration has banned the sale of food items by street vendors in affected areas, citing the risk of further transmission through contaminated water and unhygienic food handling practices. Residents have been advised not to consume water from either borewells or the Narmada pipeline until further notice.

“Bhagirathpura incident has been declared an epidemic so that required protocols could be followed in the area to contain the spread,” Verma said. “We have asked locals not to consume water from the Narmada pipeline as well as borewell water.” For the time being, residents have been instructed to rely exclusively on water supplied by municipal tankers and to boil it thoroughly before use.

The human toll of the outbreak has been severe. As of Monday, around 3,000 people have been affected over the past 10 days, with 327 requiring hospitalisation. Government officials have confirmed 10 deaths so far, though local residents and activists allege the actual number could be higher, pointing to cases of sudden illness and deaths that may not yet have been officially linked to the outbreak.

Contamination of drinking water by sewage has been identified as the most likely cause of the crisis. According to officials, complaints about foul-smelling and discoloured water had been raised by residents for months before the outbreak turned deadly. Allegations have emerged that authorities failed to act on these complaints for at least six months, allowing contamination to persist unchecked until it resulted in loss of life.

Verma, however, sought to reassure residents by asserting that the contamination was not widespread across the groundwater table. “If the groundwater was contaminated, all the samples would have shown similar results,” he said. “However, the fact that different results were obtained from adjacent borewells suggests that the issue might be localised rather than a widespread contamination problem.” According to the district administration, damaged or poorly maintained borewells may have allowed sewage to seep into water extraction points, leading to faecal contamination.

Experts note that borewells themselves do not have separate reservoirs and draw water from underground aquifers. This makes them vulnerable to contamination if sewage lines are leaking or if borewell casings are damaged, allowing surface pollutants to enter the water system. In older or densely built-up areas like Bhagirathpura, where underground infrastructure is often poorly mapped and inadequately maintained, such risks are significantly higher.

To address the immediate danger, the administration has begun repairing the 35 borewells found to be contaminated. The remaining borewells in the area are being chlorinated as a precautionary measure. Officials say repeated testing will be conducted to assess whether these interventions are effective and to determine when, if at all, borewell water can be declared safe for consumption again.

The state health department has also stepped up surveillance and response measures. State surveillance officer Dr Ashwin Bhagwat said a digital survey is being launched to map water usage patterns among households in Bhagirathpura. “We are trying to track the source of water used by families to better understand how the contamination spread and which sources pose the highest risk,” he said. The survey is expected to help health officials identify vulnerable households and prioritise medical intervention and awareness campaigns.

Meanwhile, hospitals have been instructed to remain on high alert, with additional beds, intravenous fluids and antibiotics being stocked to handle the surge in patients. Medical teams are conducting door-to-door visits to identify people showing early symptoms of waterborne illness, such as diarrhoea, vomiting and fever, and to ensure prompt treatment.

Public health experts say the Indore outbreak highlights deeper systemic issues in urban water management. Rapid urbanisation, dependence on private borewells, ageing sewage networks and weak regulatory oversight have combined to create conditions ripe for such crises. They warn that unless long-term investments are made to upgrade water and sanitation infrastructure, similar outbreaks could recur not only in Indore but in other fast-growing Indian cities as well.

For residents of Bhagirathpura, however, the immediate concern is safety and accountability. Many have expressed anger and frustration over what they describe as official apathy despite repeated warnings. “We complained again and again that the water was dirty and smelled bad,” said a local resident whose family members were hospitalised. “If action had been taken earlier, lives could have been saved.”

As investigations continue, the administration faces mounting pressure to establish responsibility for the delay in addressing the contamination and to ensure transparency in its response. For now, the declaration of an epidemic marks a turning point in the official handling of the crisis, but for families who have lost loved ones, it has come far too late.