Water Pollution - Case study

Pesticide pollution in India
One of the most terrifying effects of pesticide contamination of groundwater came to light when pesticide residues were found in bottled water. Between July and December 2002, the Pollution Monitoring Laboratory of the New Delhi-based Center for Science and Environment (CSE) analyzed 17 brands of bottled water, both packaged drinking water and packaged natural mineral water, commonly sold in areas that fall within the national capital region of Delhi. Pesticide residues of organochlorine and organophosphorus pesticides, which are most commonly used in India, were found in all the samples. Among the organochlorines, gamma-hexachlorocyclohexane (lindane) and DDT were prevalent, while among organophosphorus pesticides, Malathion and Chlorpyrifos were the most common. All these were present above the permissible limits specified by the European Economic Community (EEC), which is the norm, used all over Europe.
One may wonder as to how these pesticide residues get into bottled water that is manufactured by several big companies. This can be traced to several facts. There is no regulation that the bottled water industry must be located in 'clean' zones. Currently, the manufacturing plants of most brands are situated in the dirtiest industrial estates or in the midst of agricultural fields. Most companies use bore-wells to pump out water from the ground from depths varying from 24-152 m below the ground. The raw water samples collected from the plants also revealed the presence of pesticide residues. This clearly indicated that the sources of pesticide residues in the polluted groundwater are used to manufacture the bottled water. This is despite the fact that all bottled water plants use a range of purification methods. Thus, the fault obviously lies in the treatment methods used.
These plants use membrane technology, where the water is filtered using membranes with ultra-small pores to remove fine suspended solids and all bacteria and protozoa and even viruses. While nanofiltration can remove insecticides and herbicides, it is expensive and thus rarely used. Most industries also use an activated charcoal adsorption process, which is effective in removing organic pesticides but not heavy metals. To remove pesticides, the plants use reverse osmosis and granular activated charcoal methods. So even though the manufacturers claim to use these processes, the presence of pesticide residues points to the fact that either the manufacturers do not use the treatment process effectively or only treat a part of the raw water.
The low concentrations of pesticide residues in bottled water do not cause acute or immediate effects. However, repeated exposure even to extremely miniscule amounts can result in chronic effects like cancer, liver and kidney damage, disorders of the nervous system, damage to the immune system and birth defects.
Similarly, six months after CSE reported pesticide residues in bottled water it also found these pesticides in popular cold drink brands sold across the country. This is because the main ingredient in a cold drink or a carbonated non-alcoholic beverage is water and there are no standards specified for water to be used in these beverages in India.
There were no standards for bottled water in India till September 29, 2000, when the Union Ministry of Health and Family Welfare issued a notification (no. 759(E)) amending the Prevention of Food Adulteration Rules, 1954. The BIS (Bureau of Indian Standards) certification mark became mandatory for bottled water from March 29, 2001. However, the parameters for pesticide residues remained ambiguous. Following the report published by CSE in Down to Earth (Vol 11, no. 18), a series of Committees were established and eventually on 18th July 2003, amendments were made in the Prevention of Food Adulteration Rules stating that pesticide residues considered individually should not exceed 0.0001 mg/l and that the total pesticide residues should not be more than 0.0005 mg/l and that the analysis shall be conducted by using internationally established test methods meeting the residue limits specified herein. This notification came into force from January 1, 2004.

River pollution in India
Almost all the rivers in India are polluted. The causes of pollution may also be more or less similar. This is a case study of the River Damodar as reported in Down to Earth. The 563-km long Damodar River originates near Chandwa village in the Chhotanagpur hills in Bihar's Palamau district. It flows through one of the richest mineral belts in the world before draining into the Hooghly, about 50 km south of Kolkota. Indian industry depends heavily on this region as 60% of the coal consumed in our country comes from the Chhotanagpur belt. Coal-based industries of all types dot the area because of locational advantages and the easy availability of water and power. In addition, various industries such as steel, cement, fertilizer and explosive plants are also located here. The River Damodar is polluted with minerals, mine rejects and toxic effluents. Both its water and its sand are infested by coal dust and waste from these industries. There are seven thermal power plants in the Damodar valley. The states of Bihar and West Bengal depend almost entirely on this area for their power requirements. These power plants not only consume a lot of water but also dump ash in the valley.

Mining
As underground mines cannot keep pace with the rising demand, 60% of the coal extracted from the area comes from open-cast mines, which are responsible for serious land degradation. The disposal of rock and soil extracted along with the coal only adds to the problem.

Industries
The industries in the area do not have proper effluent treatment plants. Among the big coal-based industries, the washeries account for the bulk of the pollution in terms of the total suspended solids (TSS), oil and grease. About 20% of the coal handled goes out in the form of slurry, which is deposited in the ponds outside. After the slurry settles, coalfine (the sediment) is collected manually. Due to inadequate retrieval methods very often the water discharges into the river from the pond carries high amounts of fine coal particles and oil, thus polluting the river. The other major coal-based polluters are the coke oven plants that heat co?1 to temperatures as high as 1100°C in the absence of oxygen to prepare it for use in blast furnaces and foundries. The volatile components in the coal are removed, leaving hot, non-volatile coke in the oven, which is washed with huge quantities of water. This water that contains oil and suspended particles is then discharged into the river.

Fly-ash from the thermal power plants
Only one of the thermal power plants has an electrostatic precipitator to collect the fly-ash, while the other just make do with mechanical dust collectors. As most of these plants are located on the banks of the river, the fly-ash eventually finds its way into the river. The bottom-ash from the boilers is mixed with water to form a slurry, which is then drained into ash ponds. Most of the ponds are full and in several cases the drainage pipes are choked. The slurry is, therefore, directly discharged into the river.

Effects
The river and its tributaries are the largest source of drinking water for the huge population that lives in the valley. On April 2, 1990, about 200,000 litres of furnace oil spilled into the river from the Bokaro Steel Plant. This oil traveled 150 km downstream to Durgapur. For a week after the incident, five million people drank contaminated water in which the oil levels were 40 to 80 times higher than the permissible value of 0.03 mg/l.
The Damodar Action Plan, an end-of-the pipe pollution treatment scheme, seeks to tackle effluents. One viable option could be to switch to less polluting industries and cleaner technology. This would need strong Government initiative and also a mass movement by people.