HYDERABAD: Telangana’s growing dependence on groundwater is no longer just a water security challenge; it is increasingly becoming a public health concern, with experts warning that excessive extraction is accelerating groundwater contamination and increasing the risk of waterborne diseases and chronic health conditions.
The concern is particularly relevant in Telangana, where groundwater remains the primary source of drinking water for millions and plays a critical role in agriculture and domestic supply.
A recent international review of groundwater-related diseases identified contaminated groundwater as one of the leading pathways for illnesses such as cholera, giardiasis and diarrhoeal diseases in developing countries. The review noted that nearly half of the world’s population faces challenges linked to polluted freshwater sources, increasing the risk of disease transmission through contaminated drinking water.
Hyderabad has already extracted 96% of its annually replenishable groundwater resources, placing it in the “critical” category and just short of becoming an “over-exploited” groundwater zone. The problem extends beyond the city, with 26 mandals across Hyderabad, Rangareddy and Medchal-Malkajgiri districts already classified as critical or over-exploited, indicating that groundwater stress is spreading across the Hyderabad Metropolitan Region.
The implications extend beyond water availability. Experts say that as groundwater levels decline, the quality of the remaining water also deteriorates. “When groundwater levels decline, the remaining water becomes more vulnerable to contamination from sewage, septic tanks and polluted surface water. Over time, this increases the likelihood of people consuming unsafe drinking water,” said health expert Purshottam Kumar.
As aquifers are depleted, households respond by drilling progressively deeper borewells. That, experts say, brings an entirely new set of health risks. “Earlier, groundwater was available at around 200 feet, but in some places, borewells now reach 1,500 feet.
The deeper you drill, the greater the risk of encountering fluoride, arsenic and other heavy metals, which can significantly affect human health,” added Dr Ranga Reddy Burri, president, Infection Control Academy of India and honorary professor, University of Hyderabad.
Dr Kiran Madhala, professor and head of Critical Care Medicine at Gandhi Medical College, noted groundwater depletion has evolved into a public health challenge.
Declining groundwater levels can increase concentrations of fluoride, arsenic, nitrates and heavy metals, raising the risk of fluorosis, cancers, kidney disease and neurological disorders. Reduced groundwater availability also affects sanitation and hygiene, increasing the risk of diarrhoea, cholera and typhoid. Climate change and recurring droughts are expected to intensify these impacts.
Backed by research
The growing concern is supported by international research.
A recent review of groundwater-related diseases identified contaminated groundwater as one of the leading pathways for illnesses such as cholera, giardiasis and diarrhoeal diseases in developing countries. It also noted that nearly half of the world’s population faces challenges linked to polluted freshwater sources, increasing the risk of disease transmission through contaminated drinking water.
Evidence from Telangana suggests those concerns are already becoming a reality.
Groundwater quality monitoring in Hyderabad found nitrate concentrations ranging from 6 mg/L to 166 mg/L before the monsoon and increasing to as high as 259 mg/L afterwards. Fluoride concentrations reached 3.68 mg/L in some locations, exceeding the World Health Organisation’s recommended safe limit of 1.5 mg/L.
The problem extends well beyond the capital. Analysis of more than 2,200 groundwater samples across Telangana found fluoride concentrations as high as 13.9 mg/L in Mancherial, while nitrate levels reached 697 mg/L in Nizamabad and 683 mg/L in Kamareddy, far exceeding the WHO guideline of 50 mg/L.
The consequences of contaminated groundwater are far more serious than occasional stomach infections. “People often associate unsafe water with diarrhoeal diseases alone, but prolonged exposure to nitrate- and fluoride-contaminated groundwater can result in lifelong health problems, particularly among children,” Purshottam Kumar explained.
High nitrate concentrations have been linked to methemoglobinemia, or blue baby Syndrome, in infants, a potentially life-threatening condition that reduces the blood’s ability to carry oxygen. Long-term fluoride exposure can cause dental and skeletal fluorosis, while groundwater contaminated with human waste increases the risk of diarrhoea, cholera and giardiasis. Children are particularly vulnerable because of their developing bodies and higher water intake relative to body weight.
Those risks are reinforced by findings from Telangana itself.
A study by researchers at CSIR-National Geophysical Research Institute (NGRI) in the Wanaparthy watershed of the Upper Krishna River Basin found nitrate contamination posed the greatest health risk to infants and children. Hazard Quotient values exceeded the safe limit in 68.97% of infants and 72.41% of children, indicating substantial risks from long-term consumption of nitrate-contaminated groundwater. Adults were comparatively less vulnerable, although several groundwater samples also exceeded safe exposure limits.
The study also found nitrate concentrations increased sharply after the monsoon because of fertiliser leaching, reaching 503.49 mg/L. Nearly 29% of groundwater samples collected after the monsoon contained nitrate concentrations above 100 mg/L, well beyond the Bureau of Indian Standards’ permissible limit.
Researchers associated prolonged consumption of nitrate-contaminated groundwater with methemoglobinemia, diabetes, stomach and oesophageal cancers, and thyroid hypertrophy. Women and children were found to be more susceptible because of physiological differences and greater vulnerability to untreated drinking water.
The international review similarly warned that groundwater across India, including Telangana, contains contaminants such as fluoride, arsenic and boron, exposing more than 66 million people to health risks. Associated illnesses include cholera, diarrhoea, dysentery, dental fluorosis, typhoid, infantile paralysis, guinea worm disease, skin infections and lead poisoning.
Despite these risks, many urban households continue to rely on groundwater.
Reasons to worry
Even as Telangana has expanded drinking water infrastructure through Mission Bhagiratha and Hyderabad’s 20,000 litres of free potable water scheme, a study by researchers at the Indian Institute of Technology Hyderabad found that many middle-class families continue to depend on private borewells, water tankers, bottled water and household purification systems because of concerns over water quality and declining confidence in public water infrastructure.
Published in Asian Anthropology, the study was based on 50 in-depth interviews across Hyderabad. Researchers found widespread anxiety over shrinking groundwater availability and municipal water quality. Rather than judging water solely by laboratory standards, residents frequently associated drinking water with its taste, source and perceived purity, distinguishing between “Manjeera water”, “Godavari water”, “Krishna water”, borewell water and tanker water.
The interviews also showed how groundwater depletion has become part of everyday life.
Several residents said borewells that once yielded water at around 200 feet now require drilling between 500 and 1,500 feet, often without any guarantee of success. One apartment resident reported locating water only after drilling to 900 feet before extending the borewell to nearly 1,300 feet to secure a future supply.
Experts say many households also place too much faith in household purification systems. “Most RO systems are not regularly calibrated or validated. Once installed, they are rarely checked for filter performance or contaminant removal. Over time, these systems become more of a psychological comfort than actual protection. Heavy metals and other contaminants may still remain in the water if maintenance is poor,” said Ranga Reddy Burri.
There is still time...
For public health experts, the solution lies beyond drilling deeper borewells or installing more filters.
They argue that groundwater protection must be treated as a public health intervention rather than simply a water management issue. “Regular groundwater quality monitoring, stronger wastewater treatment, improved sanitation and protection of recharge zones are critical if we want to prevent disease rather than simply respond to it,” Purshottam Kumar said.
Experts add that strengthening water, sanitation and hygiene (WASH) infrastructure, restoring lakes and wetlands, expanding rainwater harvesting, protecting aquifers and regulating groundwater extraction are essential to reducing disease risks.
They also say investments in reservoirs, pipelines and drinking water schemes must be matched by transparent water quality monitoring, reliable distribution and protection of lakes and groundwater to restore public confidence in government-supplied drinking water.
Expanding access to treated surface water through programmes such as Mission Bhagiratha and the Jal Jeevan Mission remains the most sustainable long-term solution, they say.
However, these schemes must be backed by proper maintenance of water distribution networks to prevent contamination, while rainwater harvesting and greater citizen participation will be equally important if Telangana is to reduce its growing dependence on groundwater.