BENGALURU, India – In a small town in the suburbs of this booming city, K.V. Muniraju knows all too well the decade-old battle of securing water for his crops. With groundwater tables continuously falling, the middle-aged farmer once borrowed heavily to dig wells ever deeper.

If he was lucky, he found water. If he was unlucky, he didn’t. If he was really unlucky, he found a hint of water and proceeded to invest in the well infrastructure, only to see the well run dry and trap him in debt.

That happened to Muniraju in 1994 and 1995, when he was forced to direct water into his fields from nearby storm water drains.

Then came apparent salvation. In 1998 the nearby town installed a sewer system and discharged the untreated wastewater through the same storm water drains alongside his fields. In the 20 years since, Muniraju has had a secure water source to grow his crops.

The steady water supply, though it reeks, also contains high nutrient concentrations. That enables Muniraju to increase production while reducing input costs, such as fertilizers. His standard of living has increased – he built a stone house and sent his three sons and two daughters to school and college.

Across India, and particularly in the nation’s big metropolitan regions, countless numbers of farmers like K.V. Muniraju raise their crops with untreated wastewater. Medical specialists say farmers and their families risk serious disease from exposure to harmful sewage-borne microorganisms and metals. Scientists have measured unsafe levels of heavy metals and other toxic substances in Indian crops – posing a public health threat if consumed.

Indian public health and safety authorities have displayed limited action in tackling the impending public health crisis. Just 30 percent of wastewater undergoes any sort of treatment before being discharged in a wretched stream of industrial effluent that contains heavy metals and toxic chemicals. To date there is no regulatory framework for testing primary products, such as vegetable and fruits, for toxic contaminants. The widespread use of untreated wastewater – particularly in urban and peri-urban areas – to grow a considerable portion of India’s food supply, coupled with current inaction from officials, has converged to produce, say some scientists, a toxic time bomb in a nation that soon will overtake China to become the world’s largest.

“It is a complex nexus,” said Sumit Kumar Gautam, an environmental scientist at the Center for Energy, Environment, and Water (CEEW) in New Delhi. “If surface water is contaminated with untreated effluent, farmers use this for irrigation. The farmer is exposed to all contaminants and is likely to experience diarrhoea, bronchitis, skin diseases, eye irritation etc. The contaminants enter the soil, the biomass and thus enter the food chain. The entire food chain is contaminated because of this untreated effluent.”

The motivation for farmers to use wastewater to raise their crops is plainly evident in a convergence of three primary nation-testing challenges – rapid population growth and urbanization, increasing demand for food, and seriously depleted reserves of clean water.

Driven by economic opportunities, India’s megacities are growing fast. A 2010 study by McKinsey estimated that urban expansion is projected to happen twice as quickly as in the past – unlike any urbanization India has seen before – with 590 million people living in cities by 2030, or 170 million more than today.  

But the supply of clean fresh water to produce food is diminishing. Rivers and lakes are profoundly polluted, according to state and government studies. And groundwater reserves are shrinking fast from over pumping. Fresh water scarcity is made worse by deep and lengthy droughts that grip India with increasing regularity and ferocity. According to the latest assessment by the National Institution for Transforming India (NITI), 70 percent of the country’s fresh water – in the ground or on the surface – also is contaminated.

Fresh water, in sum, is in the worst condition in India’s history, according to the NITI report that was released in June by Nitin Gadkari, minister of water resources. India, said the study, was snared in “the worst water crisis” in its history. The report found that at least 600 million Indians – almost half the country – contend with high or extreme water stress.

The single water supply that is still plentiful, though, is a stream of treated and untreated municipal and industrial wastewater.

Digging Deeper Into Food Supplies

The Hindon River, once the lifeline in one of the most fertile and productive agricultural regions in northern India is now one of the most polluted stretches in the Ganga Basin due to the discharge of untreated, highly polluted industrial, municipal and agricultural wastewater. Key industries upstream include paper mills, sugar processing and associated alcohol distilleries, as well as dairies, textile factories, tanneries, and informal battery manufacturing units. While it is mandatory to treat industrial effluent, water pollution levels show that this is not adhered to, nor enforced.

Krishan Pal Singh, an environmental activist in Doula Village remembers when farmers could safely use surface water to irrigate. That was before the 1980s. Then industries settled in the region and abstracted groundwater and polluted surface water.

The cocktail of heavy metals and pesticides carried by the Hindon have accumulated in the river sediments and seeped into the ground. Now groundwater is polluted, too. A study in 2009 found manganese, lead, zinc, copper, chromium, iron, and elevated levels of cadmium in river sediments. The industrial wastes aggravate any potential measures to clean the Hindon and reverse the decades-old contamination.

Downstream in Muzaffarnagar, an industrial city, the Hindon River is a pitiful sight. It looks more like a sewage canal than a river. Its stench is overwhelming. A mass of solid waste in the river forms a dam, limiting its flow. Dogs roam the landfill, happily picking up pieces of meat discharged by a slaughterhouse upstream. Along the river banks, farmers harvest corn. “The water is so polluted, we can only grow resistant crops,” said one farmer. “Half of our chili plants have diseases and at times the industries discharge acid, which damages the crops. If we use river water or not – we always lose.”

A bit further downstream, farmers transplant rice paddies, standing knee deep and without any protection in untreated wastewater. The head farmer explained that skin diseases are an issue at times. But he appreciates the fertilizing qualities of the untreated wastewater and the money he saves.

Further downstream, farmers from the village of Surana in the Bagpat district, said that surface water is of such bad quality that crops are of bad quality now, too. While they have no means of testing their water or crops for toxins, they realize that the quality of crops worsen with greater proximity to the river.

The farmers link the increased rate of diseases, particularly skin diseases, to the deteriorating water quality. “Kids are born healthy, but fall ill very quickly afterwards,” one farmer said. “Over time we realized that some crops are riskier to consume than others. Lentils seem to be less contaminated, so we eat them. Other vegetables, such as cauliflower, okra, and aubergine seem more contaminated. We believe they are unfit for consumption, so we don’t eat them. We sell them to the markets in Delhi.”

Bengaluru’s Foaming Lakes

Bengaluru was previously known for its beautiful lakes, which also served as lifeline for the city by collecting monsoon water and providing clean drinking water during the dry season when all rivers went dry. Today, the lakes are full of wastewater.

Bellandur Lake and Varthur Lake have gained international attention for frothing and catching fire as a result of untreated wastewater discharges. The wastewater contains nitrogen, phosphorus and carbon. It also contains sodium, potassium, calcium, and magnesium. The chemistry causes foam to form and accumulate.

Like a giant, smelly bathtub, big balls of snowy white suds roll across the water. The suds sometimes grow to be 30 to 40 feet high and, in a blizzard of bubbles, have even stopped traffic on the decaying bridge that spans the river. The suds are a soup of detergents and surfactants from the city upstream.

The lakes also catch fire. The water contains highly flammable compounds, namely hydrocarbon and organic polymers, as well as phosphates from detergents, from industries close to Bellandur Lake.

Vishwanath Srikantaiah, an environmental activist, said that the groundwater on which the city depends, has become harder to access as wells go deeper, and that people are using more detergent to wash their clothes – which then gets discharged untreated into waterways.

Circle of Blue followed the outflow of the lakes to the Koramangala-Challaghatta valley, where it is received, by grateful farmers, for irrigation and crop production for Bengaluru and its surroundings. Surresh, Shenkar, and Ramakrishna are farmers in their 30s and 40s in the village of Mugalur, downstream of Varthur Lake.

“We use the little groundwater we have to grow our own food. The rest we sell to buyers who bring it to Bengaluru’s markets. We don’t eat it.”

When groundwater got scarce, the river became their lifeline. Until three years ago they could use it for their crops. Since then, water was mixed with foam and the quality and productivity of the crops went down – for rice even by 50 percent. ”Foam is in pipes, in the fields. It’s toxic, as at times when it foams badly, we can set the foam on fire. We use the little groundwater we have to grow our own food. The rest we sell to buyers who bring it to Bengaluru’s markets. We don’t eat it,” they said.

Their buyers, they said, know that untreated wastewater is used to grow the crops. But it does not concern them. Their crops enter the food supply unchecked.

Heavy Metals Through Untreated Wastewater

It is well-documented in the scientific literature that water used for irrigation containing heavy metals is a crucial pathway for the toxic chemicals to enter the food supply chain and be absorbed by consumers. Various studies have shown that long-term irrigation with wastewater results in a build-up of heavy metals in the soil – even if the concentrations in the wastewater are low. That, in turn, results in toxicity to plants and food contamination. Metals also accumulate in the body, increasing in concentration over time, which can result in cancers, genetic mutations, and malnutrition.

Despite the scientifically proven pathways for contamination, and the prevalence of wastewater-irrigated agriculture, surprisingly few raw food sample tests have been conducted across India.

As part of a research project from 2000 to 2003, the UK Department for International Development tested heavy metal contamination in spinach from various markets in Delhi, including the wholesale market in Azadpur. Every sample exceeded the U.N. Food and Agriculture Organization’s international CODEX safety standard for lead. Nearly three quarters of the samples – 73 percent — were found to exceed accepted PFA global public health safety standards for lead. Almost a quarter – 24 percent — contained twice the PFA standard. A fifth of the samples also had markedly elevated levels of zinc.  

In a 2015 study, a team of Indian researchers assessed residues of cadmium, lead, zinc, and copper in vegetables in five markets in Delhi. They found that a significant proportion of vegetables contained levels of zinc, lead, and cadmium above safe concentrations.

In a third assessment, of 22 varieties of vegetables grown in the Delhi region, researchers found nickel and lead concentrations in excess of permissible limits.

Similarly, in Bengaluru, food samples from various markets showed that all tested food – including fruits/curd, root vegetables, and leafy vegetables – had at least one heavy metal residue that exceeded the Indian Food Standard. When applying international standards on food safety, the picture becomes even bleaker.  Most samples exceeded all international thresholds for analysed heavy metal content.

In 2012, The Energy and Resources Institute (TERI), based in Delhi and one of India’s most renowned research organizations, assessed the health risks from eating crops grown on the banks of the Yamuna River, a tributary of the Ganga that flows through New Delhi. It found that the agricultural soil along the Yamuna contained levels of nickel, manganese, lead, and mercury above international standards. Treated and untreated wastewater discharged to the river was identified as the source.

TERI also found that vegetables grown in the Yamuna flood plain – a 22-kilometer (14-mile) stretch – had higher levels of heavy metals. TERI tested urine and blood samples from women and children in that area and found significantly higher levels of mercury, chromium, and lead than those of the rural population. Most strikingly, 23 percent of sampled children had blood lead levels above 10 micrograms per deciliter, a widely accepted international safety limit.

The Detrimental Effects of Heavy Metals

One more seminal question confronts Indian food growers – the safety of the country’s agricultural exports. India is the world’s 15th largest exporter of agricultural, fishery and forestry products. The United States is India’s top export market. Other important markets include Vietnam, United Arab Emirates, Saudi Arabia, Bangladesh, China, Iran, Malaysia, Pakistan, and the United Kingdom.

The world is well aware of India’s wastewater-contaminated food exports. The United States ranks India among the three nations that most consistently violate American import safety limits. Food grown in India accounts for 60 percent of the items that United States Customs inspectors refuse to allow into U.S. markets.

Two years ago, the UAE barred Indian imports of chili peppers, mangoes, and cucumbers unless each shipment arrived with official residue analysis reports. The UAE is one of the top four global markets for Indian fruit and vegetables and one of the world’s biggest importers of Indian mangoes and onions.

The National, an important UAE newspaper, warned that the lack of regulatory oversight in the food sector, and the persistent failure to meet international quality standards, threaten India’s farmers and food companies. “An initiative is needed in the regulation of food exports. The introduction of better controls with clear guidelines for acceptable produce would dramatically help Indian’s agricultural industry. Time is running out for Indian farmers as consumers around the world have become more savvy and have options closer to home.”

Even knowing the risks from irrigating crops with untreated wastewater, most Indian farmers – especially in the peri-urban areas – have no alternative. Close to Bengaluru, farmer K.V. Muniraju projected that if wastewater started to be treated, it would be used for other purposes. It would not pass his farm anymore, he said.

“We are praying that the wastewater flows will last as long as it takes for our children to find other jobs so that they can support our family.”