It is a festivity of colours each day here, as colourful streams of water gush down the drains and fall into a huge pool of muck and fluid. This concoction of colour and grime is churned at high speed to split clean the slime from the water. Less than 50km off the textile city of Coimbatore, the hosiery hub of India, Tirupur, houses 6,250 factories that spin out garments in pleasing hues for the export market. Unlike other dyeing centres in the country, environment-conscious Tirupur has its waste treated within each unit, with no toxic waste escaping into the storm water drains anywhere in the city. How do they manage this? Mohana goes inspecting.