Bleaching unit owners here have come up with a demand that the Tamil Nadu Pollution Control Board should not insist upon them to implement the zero liquid discharge (ZLD) norms as no salts or hazardous chemicals were used in the bleaching process.


“Classification of bleaching units under ‘orange category' of industries itself is the indication that it did not possess any significant threat to the environment.

Hence, it is wrong to make us follow ZLD norms by putting under the same bracket of dyeing units which are under polluting red category,” Tirupur Bleachers Association president S. Chinnasamy told The Hindu .


Mr. Chinnasamy said the TNPCB, in future, should allow bleaching units to discharge treated effluents subjected to a maximum TDS (total dissolved solids) level of 2,100 ppm (parts per million).


The bleachers' feel that it was the TNPCB's blanket imposition of ZLD norms for both bleaching and dyeing units by wrongly treating the two sectors on a par with each other only resulted in the closure of the 150-odd bleaching units along with the almost 600 dyeing units by a court order for indiscriminate discharge of effluents into River Noyyal.

TNPCB District Environmental Engineer R. Kannan said that bleaching units were of course been put under ‘orange category,' which was a classification made on the basis of polluting potential of an industry by virtue of the manufacturing process involved.


“Technically, bleaching units with individual effluent treatment plants (those which were not attached to Common Effleunt Treatment Plants (CETPs) which have dyeing units also as its members) can be allowed discharge of treated effluents subjected to TDS level of 2,100 ppm provided they use soft water (with low salinity) supplied by agencies like New Tirupur Area Development Corporation Limited in the bleaching process,” he said.


Industry sources pointed out that a good chunk of bleaching units repeatedly violated the appeals for using soft water instead exploited the highly saline groundwater.

TNPCB sources added that closure of bleaching and dyeing units was necessitated as they were ‘inter-pressed' in the single ‘Tirupur knitwear cluster' with their activities linked in the manufacturing chain.