Opinion - News Analysis   

Prevention the better cure

THE BIG industries, which are more easily noticed and monitored, are not always the biggest polluters. By sheer numbers, small industries can create major problems. A classic example is Tirupur in Tamil Nadu, which exports some 71,000 tonnes of knitwear annually and produces another 50,000 tonnes for domestic use. Some 4,000 small-scale units are involved in various segments of this activity. Together, these units consume over 90 million litres of water a day, a quantity sufficient for a town of two million people.

The industrial processes produce wastewater containing about one tonne of dyes daily. Although central effluent treatment plants have been set up, the salinity is not removed and it is not known what sort of toxic chemicals remain, and in what quantities, when the wastewater is discharged into a nearby dry river, points out Ramesh Ramaswamy, an industrial ecologist who has published a study on the Tirupur problem. The groundwater around has been polluted to such an extent that more than half the industries' water requirement is met by tankers from over 50 km away.

The large number of small-scale industries and informal sector units pose major problems for pollution control, points out the "India Development Report 2002" published by the Indira Gandhi Institute of Development Research. Since such units use outmoded and inefficient technologies, the amount of waste they generate is disproportionate to their size. They lack the knowledge, funds, technology, space and skills to treat their effluents. There are 3.2 lakh small-scale industries, producing about 8,500 products, some of which are highly polluting. The net impact of these units nearly equals that of all the large and medium industries put together, the report says. Enforcing the pollution regulations in these units is "painfully difficult" and aggravates the problems of the regulators, already constrained by understaffing, meagre resources, and, often, a lack authority.

Although technologies do exist to remove pollutants from groundwater after it is pumped out, most of these methods are very expensive to implement, says Dr. Jack Barbash, an environmental chemist in the United States who has extensive experience with groundwater pollution. "The least expensive way to prevent humans and other non-target species (both terrestrial and aquatic) from being exposed to harmful chemicals is simply to prevent the chemicals from entering the hydrological system in the first place," he told The Hindu.

Prevention requires regular monitoring and understanding of the quantity and quality of pollutants entering the groundwater. That is a mammoth task in itself. It requires analysing the groundwater for a wide range of potentially toxic chemicals, including many inorganic and organic compounds, heavy metals, and pesticide residues. The equipment for such analysis is expensive and each test, such as for pesticide residues, can also be quite costly, points out V.N. Sivasankara Pillai, an environmental chemist at the Cochin University of Science and Technology.

It is not sufficient that dangerous wastes from large industries are monitored. As an FAO-sponsored study remarked: ``The dispersed nature of sources of pollutants is a core challenge facing both monitoring and control of groundwater pollution related to agriculture. Unlike industry or municipal sewage systems, agricultural pollutants are dispersed over large land areas. While return flows in drainage canals can be monitored, it is difficult to determine the extent of direct seepage of pollutants through soils and into the groundwater until contaminant concentrations in groundwater become significant.''

A nationwide system of monitoring and surveillance is essential, says Sunita Narain, director of the Centre for Science and Environment. In order to reduce the magnitude of the task, a sampling method, with water from a few randomly chosen wells being tested, could be thought of.

In the end, monitoring and surveillance can only be a prelude to action. Agricultural chemicals, such as fertilizers and pesticides, can be applied more effectively, thereby reducing the quantities which are used. The CSE has been demanding an effective pesticide policy to ensure that chemicals registered and sold are `safe' for use. The permissible limits for contaminants in food products need review, and this could lead to a wider discussion regarding permissible levels of pesticide and fertilizer use in agriculture and horticulture. Instead of subsidising chemical pesticides, the Government should be promoting bio pesticides, says Ms. Narain.

The method of industrial ecology will be to analyse material flows in a region and, if required, certain industrial sectors of concern, according to Mr. Ramaswamy. Such analysis will serve as a diagnostic sheet, showing the major sources of pollution that need priority action. Legal provisions, such as the Hazardous Waste Rules, needed to be implemented fully.

In the case of small industries, many of which are clustered together in industrial estates, the India Development Report suggests delegating some of the responsibility of monitoring and enforcing pollution controls to the industry associations. The associations would have an incentive to regulate and discipline their members as otherwise all units in the estate could suffer. The experience at the Ankleshwar Industrial Estate in Gujarat, the largest estate of chemical industries in Asia, shows that such an approach, though not without problems, has potential.

It cannot be assumed that sewage, household garbage and other forms of municipal solid wastes are harmless. These too need to be carefully handled and properly disposed of. It is necessary to act now and stop the contamination of groundwater, warns Ms. Narain. Otherwise, it would only worsen and become more difficult and costly to handle. — N.G.R.

Printer friendly page  
Send this article to Friends by E-Mail

Opinion

News: Front Page | National | Southern States | Other States | International | Opinion | Business | Sport | Miscellaneous |
Advts: Classifieds | Employment | Obituary |

Stories in this Section

• How safe is our water?
• Monitoring minimal
• Prevention the better cure

Copyright © 2003, The Hindu. Republication or redissemination of the contents of this screen are expressly prohibited without the written consent of The Hindu