Poison river

Poison river

This article began with a very simple thought. The Centre for Science and Environment's (cse) campaigner on sustainable water management, Himanshu Thakkar, had prepared a draft paper on urban drinking water in which he had reviewed a number of documents and newsclippings that the Centre's library had gathered on the subject. As I read through the draft, I found document after document lamenting the fact that people did not have adequate water and that massive investments would have to be made to ensure the availability of enough water for drinking and other domestic needs. But the literature contained little reference to 'clean water'; and this reference pointed essentially to bacteriological contamination of water. There was almost no reference to the chemical contamination of our water sources, especially with growing industrialisation and use of chemicals in modern agriculture.

I wondered whether this was another one of those 'untold stories' which nobody cares to investigate and bring to the attention of the public. Suddenly, I came across a news item which described the woes of the people of Agra who suffer from pollution of the Yamuna river by India's capital city, Delhi. If Agra was suffering because of Delhi, was Delhi suffering because of the industrial and agricultural activities in the upstream state of Haryana? Haryana, as we all know, is a major Green Revolution state, using massive quantities of pesticides. Besides, industrial growth has also been taking place in the state with very little pollution control. Where are all these agricultural chemicals and industrial toxins ending up? The answer was obvious: in the Yamuna, which brings drinking water to Delhi. Something was very wrong here; we were deeply ignorant about a critical issue that literally affects our daily lives.

Since Himanshu was involved in our work on traditional water harvesting systems, I decided to ask Down To Earth reporters Max Martin and Rajat Banerji to find out the level of chemical contamination of the Yamuna; whether this contamination was being removed before drinking water was supplied to the people of Delhi; and, what was happening to the people of Agra. Rajat took the responsibility of following the river down till Delhi, and Max was to follow the river from Delhi to Agra.

Today, when science has made so much progress and almost nothing is beyond human reach, the biggest cause of death is ignorance. What Rajat and Max found -- and they found an enormous lot -- revealed that there is some scientific activity going on in this field, though it is far from being brought to the notice of the public. Their findings, which are presented to the reader in the following pages, make it very clear that public ignorance is the biggest threat to public health.

Rajat and Max tell us that the river is badly polluted and getting worse every hour. That despite this, nobody treats the raw river water to get rid of the contaminants. Because costs are high. Because we have not even thought of treating drinking water for chemical contamination. As a result, all the poisons are coming straight to us, day after day -- probably a major reason why people in Delhi have so much pesticide residues in breast milk and fatty tissues. Thus, industrial and agricultural development in Haryana is taking place at the cost of the health of millions in Delhi. And Delhi, in its turn, is urbanising and industrialising at the cost of Mathura and Agra. A tale of 'who cares what happens to those who come after us'... down the river, down the economic ladder and down the generations. Whether they live or die is none of our concern. If you get angry reading this report, do write to us.

Anil Agarwal january 2, 1997. Alarm bells began ringing in capital Delhi's water treatment plants when massive amounts of ammonia were detected in the waters of the Yamuna at the Wazirabad barrage. The two treatment plants at Wazirabad and Chandrawal promptly curtailed their production of potable water by half, and Delhi's citizens reconciled themselves to yet another harrowing day without water. The ammonia, said chief engineer A K Gupta of Delhi Water Supply and Sewage Disposal Undertaking (dwssdu), had seeped into the waters owing to the release of industrial wastes from Haryana.

This was, of course, a tip of the proverbial iceberg. The Yamuna had been named after the sister of Yama, the dreaded god of death in the Hindu pantheon, so says mythology. In fact, with the presence of alarming levels of highly toxic pesticides, heavy metals and carcinogenic chemicals in the waters of the river just before it reaches important waterworks, mythology could well have a touch of the prophetic in this case.

With an annual flow of about 10,000 cubic metres (cu m) and usage of 4,400 cu m (of which irrigation constitutes 96 per cent), the river accounts for more than 70 per cent of Delhi's water supplies. The presence of deadly pesticides like ddt, aldrin, dieldrin, heptachlor, benzene hexachloride (bhc) and endosulfan in its waters has been a long-acknowledged fact. Some of these -- whose traces have far exceeded limits considered fit for human consumption -- are persistent organochlorines (ocs) responsible for causing serious maladies like cancer.

Available water treatment facilities are not capable of removing the pesticide traces. Waterworks laboratories cannot even detect them. Worse, Yamuna leaves Delhi as a sewer, laden with the city's biological and chemical wastes. Downstream, at Agra, this becomes the main municipal drinking water source. Here too, existing treatment facilities are no match for the poisons. Thus, every consumer in Delhi and Agra ingests unknown amounts of toxic pesticide residues each time he or she drinks water.

The trouble with our rivers
India consumes around 86,311 tonne (t) of technical-grade insecticides annually to cover 182.5 million hectare of its cultivated land. Insecticide Pollution in Indian Rivers, a study carried out by N P Agnihotri, S P Mohapatra, V T Gabhiye and Manju Raina of New Delhi's Indian Agricultural Research Institute (iari) (published in The Environmentalist in 1995), found traces of beta isomers in Indian rivers, including the Yamuna. The beta isomer, which is a carcinogenic oc, accumulates in river waters due to its stable chemical structure, low vapour pressure and high resistance to microbial degradation. The study noted that most Indian rivers passed through agricultural fields and were contaminated by insecticides used for crop protection. "Residues of persistent organochlorines are found in many rivers. ddt, aldrin and heptachlor have been found in excess of guideline limits," it said, adding that leaching from agricultural fields was the singlemost important non-point source of pollution (one which is unspecified, and therefore, cannot be measured accurately) to the aquatic environment.

An estimated 57 million people depend on Yamuna's waters. According to the iari study, "Although phased out in the West, persistent organochlorines are used in large quantities in India because of their effectiveness and low cost. Production of organochlorines is more than the production of all other insecticides taken together." It goes on to point out an alarming truth: with increasing population and frequent outbreaks of diseases, the amounts of pesticides that would be used for higher agricultural yields and for vector control would increase correspondingly.
 

The central pollution control board (cpcb), on its part, had found endosulphan residues -- alpha and beta isomers -- in the Yamuna in 1991. An earlier study by H C Agarwal (Delhi University) had traced ddt residues amounting to 3,400 nanogram per litre (ng/l). However, later cpcb studies showed reduced ddt levels. To gauge the immensity of the threat which looms over our collective lives, we need to trace the river's flow -- which has been divided into five segments ( see box: The segments ) on the basis of hydro-geomorphological and ecological characteristics -- down to its final reaches.

Upper segment
The Haryana factor: Wastes from Yamuna Nagar, Panipat, Sonepat, Karnal and other towns of Haryana and its vast agricultural fields significantly contribute to the pollution load in the river. Industrial discharges change the physico-chemical properties [such as hardness, conductivity, ph value, turbidity, chemical oxygen demand (cod) and dissolved oxygen (do) of the water, thereby affecting aquatic life. Certain natural geological formations are also a known source of some chemicals and heavy metals. For instance, in Haryana, natural sources contribute heavily to pollution in the river near Panipat; drain no viii (which branches off the Western Yamuna Canal or the wyc) receives 21.9 t of chlorides per day from natural sources.

Then there is the persistent presence of pesticides. The consumption of pesticides in Haryana in the years 1995-96 was to the tune of 5,100 t. Out of this, bhc accounted for 600.24 t, malathion 831.48 t and endosulphan, 263.16 t. The state department of agriculture estimates that 12.5 per cent of the Yamuna basin has forest cover, 27.5 is wastelands, 53 per cent is agricultural land and the remaining area, villages, towns, cities and roads. There are plans to bring an additional 27.5 per cent under agriculture; the increase would not only mean more abstraction from the river, but also greater use and subsequent runoff of fertilisers and pesticides.

A K Mehta of the state environment department agrees that agricultural runoffs could be dangerous for people who consume this water. Terming pesticide and fertiliser residues as "slow poisons", he says that the state government had only recently awakened to this source of pollution. "We have been trying to get some research institute to do this study for us for the past year-and-a-half," he states. "Somehow, the plans haven't been finalised and we are hoping the agricultural university at Hissar will take up the research. " He points out that it would be necessary to study the effects of fertilisers and pesticides on soil salinity, their dissipating powers, and finally, what amounts enter the river.

mef officials state that agricultural runoffs being a non-point source of pollution, it is difficult to quantify what percentage gets into the river. "This would depend on the nature of soils, vicinity to the river, or the drain that eventually ends up in the river." They too do not have any studies to specify either the amount or trace the precise areas that cause this pollution.

Mapping the flow in Haryana: Yamuna's pollution starts from Tajewala in the upper segment. At Tajewala, two canals, the wyc and the Eastern Yamuna Canal (eyc) divert all the river waters -- save in the three monsoon months -- into Haryana and Uttar Pradesh (up). The wyc crosses Yamuna Nagar, Karnal and Panipat ( see maps ) before reaching the Haiderpur treatment plant (which supplies part of Delhi's water), receiving wastewater from Yamuna Nagar and Panipat.

Drain nos ii and viii branch off the wyc to augment the water in the river. Another augmentation canal branches out of the wyc at Yamuna Nagar, and rejoins the canal about 80 km further downstream at Karnal. All domestic and industrial discharges from Yamuna Nagar is let out into this canal. Water from the augmentation canal is used for irrigation. However, when excess water from the wyc is let into it, pollutants are flushed into the wyc downstream at Karnal. Thus, a few times a year, there is a sudden and massive increase in pollution loads when the water reaches Haiderpur.

Furthermore, at Panipat, discharges from the Panipat sugar mill and distillery are let out into a disused canal, which has a kutcha dam across it. Sometimes, when the effluents cross the dam, it results in a whopping increase in biological oxygen demand (bod) loads in the wyc. A cpcb inspection report estimated that there were 1,00,000 cu m of effluents in the disused canal, having a bod level of 1,380 mg/l. According to the report, when this water enters the wyc, it carries with it a total of 125 t of bod and the bod levels reach 17 mg/l at Haiderpur; the acceptable bod levels for raw water meant for treatment are three mg/litre.

Delhi, The biggest culprit

"Round-the-clock monitoring by a network of zonal laboratories and a central laboratory ensures water quality. In Delhi, where people are very vocal, we cannot afford to be lax even for a moment," claims a dwssdu spokesperson. However, Delhi itself is the Yamuna's biggest polluter. "The stretch in the vicinity of Delhi (between Delhi and the Chambal confluence) is highly degraded and not fit for any designated use," says the cpcb's 1996 Report on Water Quality Monitoring of Yamuna River.

Yamuna enters Delhi at Palla village 15 km upstream of Wazirabad barrage, which acts as a reservoir for Delhi. Delhi generates 1,900 million litre per day (mld) of sewage, against an installed wastewater treatment capacity of 1,270 mld. Thus, 630 mld of untreated and a significant amount of partially treated sewage enter the river every day.

The Wazirabad barrage lets out very little water into the river. In summer months especially, the only flow downstream of Wazirabad is of industrial and sewage effluents. Lesser discharge means lesser river flow and thus, greater levels of pollution.

Water treatment plants have been known to face the prospect of closure due to high pollution loads in the raw water. Risk Assessment of the Yamuna River , the report of an Indo-Dutch government project on water quality monitoring stations that was released inJanuary 1996, notes that the Haiderpur water intake had, at an average, to be closed five times a year. "These 'accidents' were mainly related to flushing of drains and canals upstream of Delhi, without appropriate communication between the concerned authorities," says the report. However, dwssdu authorities maintain that they would get to know any change in the pollution load on wyc six hours before it reached Haiderpur, as water is monitored upstream. In February 1996, the Wazirabad treatment plant had to down its shutters for eight hours on a day when the organic pollution load of the raw water was unusually high. In surface water, do level has to be at least four mg/l to make it fit for use after treatment; at Wazirabad, the do level was nil. This depletion was caused by effluents from breweries in Panipat.

From the Okhla barrage, which is the exit point for the river in Delhi, the Agra canal branches out from Yamuna. During the dry months, almost no water is released from this barrage to downstream Yamuna. Instead, discharges from the Shahadara drain join the river downstream of the barrage, bringing effluents from east Delhi and noida into the river. This is the second largest polluter of the river after the Najafgarh drain.



Pesticides: ignoring the main problem: But the main problem comprises of undetected and untreated chemical impurities -- pesticide residues. Delhi, so far, seems to have studiously ignored the problem. Asked specifically about pesticide contaminants such as ocs in water, a dwssdu spokesperson replied: "We do not test for them." A waterworks expert with the undertaking points out: "We do not have the system. In Delhi, if you want to test for pesicide contaminants, you will have to send the samples to Sriram lab." Waterworks officials in Delhi and Agra point out that pesticide traces cannot be removed with conventional treatment.

"Organic substances can be assimilated in freshwater, provided there is enough freshwater in the river," states R Dalwani, scientist, mef. "But for micropollutants such as pesticides, only more freshwater can reduce the percentage of traces in water. These cannot be dissolved or assimilated, but certainly can be diluted to an extent." The river has a dilution requirement of 75 per cent, which implies that for every 100 l of wastewater, 75 l of freshwater is required. Scientists state that with the flow of water, pollutants (especially organic pollutants) degrade to a large extent. But at every step, this purified water is abstracted, and larger and larger loads of pollution enter the river.

Yet, the fact remains that no amount of freshwater would make traces of micropollutants such as pesticides go away. Also, stagnant water hinders pollution dispersion and assimilation; the mainstream water stagnates at the different barrages that have been built on the river. While they agree with the proposed solution that releasing water into the river at Tajewala could help in dilution and assimilation of pollutants, mef officials also point out that such decisions were entirely political, and not based on the need of the hour.

Buck-passing and lame explanations
Though the government has elaborate water quality monitoring systems, studies or efforts to minimise the entry of pesticides into the river are non-existent. The mef claims that its job is to keep track of pesticide sources such as traces from industries. It professes that in instances where pesticide traces from agricultural fields become a cause for concern, it informs the ministry of agriculture. But as of now, other than the proposal to ban ddt from agricultural use throughout the country, nothing has been done about pesticide traces in the Yamuna. Or for that matter, any Indian river. "Large amounts of pesticides and fertilisers do enter the river while it traverses Haryana before entering Delhi," admits A K Mehta, senior scientist with the department of environment, Haryana. "So far we have not carried out a study as to how much enters from which specific district, nor have we been able to get some outside agency to do so."

Government agencies involved in monitoring tend to underplay these levels of pesticides, saying that the traces settle in the river sediment. "This contaminated river sediment gets washed away during monsoons," says Virendra Vats, a senior scientist with the Yamuna Action Plan. But not all of it, as recent studies would imply. The report of the Indo-Dutch project states, "Discharge of effluents from domestic, industrial and agricultural sources are reflected in the water quality of the Yamuna river water and the wyc. In addition, pollutants are absorbed by the sediments in the river, the drains and the wyc. This may result in high concentrations in the water of the Yamuna and wyc when the drains are flushed or at the start of the monsoon." R C Trivedi, senior scientist with the cpcb, who has been working on monitoring pollution levels in the Yamuna for almost 15 years, corroborates: "There have been many instances when dead fish are found in the river as soon as the monsoons get underway. This is because of the sudden rise in bod levels."

Vats throws up his hands about the government's inability to monitor the pesticides influx into the river system: "It is difficult to quantify what percentage of pesticides or fertilisers enter the river, this form of pollution being a non-point source of pollution. We can only identify point sources of pollution (those that are known to bring in pollution), and make suitable recommendations to lessen pollution loads entering from these sources."

This lack of interest is evident everywhere. Even the Indo-Dutch project report skirts the issue of solution to the problem. When Down To Earth met T D Dogra, head of the department of forensic medicine and toxicology at New Delhi's All India Institute of Medical Sciences with data of pesticide and other micropollutant traces in 19 stations on the Yamuna, he declined even to see the data. Ironically, Dogra is involved in studying the effects of pesticides on users like farmers and farmhands. "The main problem, as far as pesticides go, are faced by the actual users. City dwellers get minor pesticide traces from vegetables and other food items they consume," he says. However, he admits that ingested pesticides, which were slow poisons, manifested themselves in the long run in numerous illnesses.

Treatment technologies
They do not come cheap : Water treatment technologies in practice in the West are mostly governed by steep costs, something which India can ill-afford. Says Mary Taylor, senior research officer of the Friends of the Earth, a global environmental ngo, in the uk, "The estimated capital costs to remove pesticides in uk (which has one-sixteenth the population of India) is expected to be us $1.5 billion, and running costs would also be significant." Besides, "it is now widely acknowledged that conventional water treatment processes, based on chemical coagulation and filteration or biological slow sand filteration, have little capacity to remove water-soluble pesticides," say Western experts.

One way of removing pesticides is by adding granular activated carbon (gac) to sand filter beds. It is an expensive procedure since the cost of carbon determines the expense; greater the contamination, more the use of carbon and higher the cost. According to a paper presented at a symposium on 'Pesticides and Water Industry' in the uk, "These processes (using ozone, which is used to oxidise pesticides, and gac) were not originally installed for pesticide removal, but for taste, colour and other reasons." The paper says that for a process designer, it is essential to know what is the nature of the applied load (of pesticides); the variability -- average concentrations of each pesticide; raw water peak concentrations; and seasonal and time variations. It is also essential to know the levels of other materials to establish the capacity of ozone to oxidise pesticides, or activated carbon to remove them. The paper also says that both ozone and gac can introduce new problems in drinking water -- organic and inorganic breakdown products resulting from ozonation, fragments of gac or changes in biological solubility. Also, these processes and the role of ozone in pesticide removal is not yet fully understood.

Another procedure in use in desalination plants, which remove salts from brackish and sea waters, involves reverse osmosis membranes. However, removal of organic materials (including pesticides) depends on a wide range of variables such as molecular weight. Pesticides are generally highly water-soluble and have low molecular weight; hence it is difficult removing them using membranes. Moreover, after a period of time the membrane becomes fouled and toxic substances begin to appear in the treated water.

In Delhi, the treatment system incorporates prechlorination, coagulation with alum, sedimentation, clariflocculation, filteration (using sand beds) and chlorination. However, this cannot remove pesticide traces in the water. According to S D Badrinath, a water treatment expert, "Flocculation may remove five-10 per cent of the pesticide traces in raw water. But chlorination may oxidise the various pesticide traces and eventually aggravate the situation." He suggests cheaper methods of treatment which India can go in for, like capping the filter with bituminous charcoal or coconut shells.

According to the Indo-Dutch study, one way in which pollutant loads can be controlled is by better communication between the different agencies involved in the management of the Yamuna, its canals and the water treatment works in Delhi, and by upgrading the monitoring capabilities. This would serve to provide forward information to water treatment plants as to when a heavily polluted mass of water was due to reach certain waterworks. But these suggestions avoid the problem of agricultural runoffs.



Catchment protection: Western researchers are coming to the conclusion that protecting the catchment from chemical contamination -- by switching to organic or biological farming methods and curtailing the use of pesticides and fertilisers -- is possibly the best way to deal with the problem. According to cse researcher Sangeeta Agarwal who spoke to officials of the Sacramento department of utilities, California (us), which faced problems with pesticide contamination from rice fields upstream: "The problem was resolved by persuading polluting farmers to use pesticides in such a manner that it does not enter surface water."

A similar situation confronted New York three years ago. When the city awoke to the fact that the E coli bacteria was present in its water, it examined its 3,200 sq km watershed area. Increased sewage and septic discharges as well as agricultural runoffs had entered the water supplies, leading to a situation when the 'champagne of municipal water' had to be boiled before being consumed. When the city appealed to the farming community in the catchment area, the farmers cried foul about New York's attempt at 'throttling' their development. The city realised finally that it would cost only $2 billion to buy off 32,400 ha of land compared to the requisite $8 billion for water treatment plants!

Various techniques have been developed to assess the runoff of pesticides from agricultural areas into the rivers and groundwater. However, these require considerable collection of data and no studies of this type have been conducted in India. According to a study on Risk Assessment and Catchment Protection (Loughborough University of Technology, uk, 1992), "Increasing numbers of water pollution incidents have resulted in the need to assess multiple demands placed on all catchments." The study points out that it is imperative to answer certain questions: What is the level of contamination? Are sources (of drinking water) likely to be affected in the future and if so, to what degree? Also, about changes in agricultural practices or intensity needed in catchment, or part of catchment to achieve acceptable water quality; the impact of new chemicals/practices; and, the most cost-effective solutions in catchment control and water treatment.

To understand the route pesticides take once applied on crops, models using the mechanism of water movement (surface and groundwater), adsorption on soil organic matter and biodegradation are needed. Spatial data on distribution of soil type, with physico-chemical properties of pesticides, help calculate the fate of the pesticide in the environment. In the uk, a number of modules for assessing risk of drinking water contamination already exist. Some of these have been tested in a groundwater catchment study, which quantified pesticide applications to selected water catchment areas. The application rates were combined with crop census data to provide monthly totals for all pesticides used within the area. But this remains a frontier technology. Additionally, sanitary surveys can be undertaken throughout the catchment area to confirm the possible effects of industrial, domestic and agricultural land use.

The challenge ahead: In India, public opinion over the issue is growing. Numerous public interest litigations have forced the mef into an alien arena: that of accountability. This has made the cpcb, the Haryana spcb and other agencies take note of what is getting into the river and the ways and means of lessening such entry. Several polluting units which discharge into the river and the canals and drains that lead to it, have been forced to instal water treatment facilities. However, cpcb officials admit that high operational and maintenance costs of the facilities and the apathy of individual units limit their usage.

Obviously, even developed nations are finding that new -- and expensive -- technologies will be needed to remove pesticide residues from drinking water. In a country like India, where pollution control is yet to become a serious issue, applying the best method -- that of protecting catchment areas from pollution -- may be a tall order. Perhaps the only way this could change is if the end consumer of the water refuses to ingest such deadly poisons, and demands his or her legitimate right to clean drinking water.

Another issue is that of appropriate property rights. Maybe things will change when the people of Delhi get the right to sue Haryana for polluting their drinking water and the people of Agra get the right to sue both Haryana and Delhi together. Just as a private water supply company has recently sued the French authorities for not keeping the river adequately clean, making it difficult for the company to supply clean water to its customers ( see box: The French connection ). Who does the Yamuna belong to, after all?