The Noyyal, which rises from Vellingiri hills in the Western Ghats, once surrounded the township of Coimbatore with its canals, tanks and rivulets. Of late, the river has been facing a slow death.
The interconnected tank and canal system was believed to be built by the Chalukya and Chola kings. While they helped maintain a stable ground water level through percolation of subsoil water, flooding was prevented by channeling surplus water from the river to these tanks. But, today the river is breathing its last, thanks to industrialisation and urbanisation.
While the textile industry in Coimbatore and Tirupur contributes one-fifth of the total exports from India, untreated sewage and industrial effluents from the industries here has stifled the river. Textile industries in Tirupur use bleaching liquids, soda ash, sulphuric acid, hydrochloric acid, sodium peroxide and various dyes and chemicals for dyeing and bleaching processes. An article published in Centre for Earth Studies points out that the acidic waste water contained dissolved solids which increased the biological and chemical oxygen demand of water. With no fresh water available for dilution, ground water has become unsuited for irrigation. This has taken a toll on the agriculture in the region.
Very harmful
According to Siruthuli, an NGO that works for the restoration of the river, research conducted by various institutions, both in summer and winter revealed that the content of TDS (Total Dissolved Solids) levels and poisonous substances are extremely high to the extent of causing severe damage to the human systems and ecology.
Though the Water (Prevention and Control of Pollution) Act of 1974, every industry is required to get consent to discharge its effluents, the State Government had exempted Tirupur to promote the industries here. Finally pressure from the civil society and judicial intervention led the TNPCB to insist on effluent treatment facilities in Tirupur.
The Government, with support from NGO Siruthuli, had embarked on restoration activities.
Recently, the State Government had offered aid for common effluent treatment plants.
What you could do?
Visit tanks and dams to understand the extent of the problem.
Conduct pollution test with the help of teachers.
Organise awareness campaigns on the need to protect water bodies.
Keep track of restoration activities.
