Water is used for cooling of the processes and in some cases as part of the chemical process.
In the polymerisation and spinning processes, the majority of the water used is required for cooling. After only a moderate temperature increase, this water is returned to the river in an unpolluted condition.
The water used within the production process, industrial waste water, is purified in special, biological waste water treatment plants.
Emission to water, just like emission to air, is strictly controlled by European and national legislation, and laid down in the environmental permit. Depending on the permit, online and regular emission-to-air measurements have to be made and reported to the authorities.
The polymerisation process is described by the Best Available Techniques (BAT), which are compiled in a BREF (BAT-Reference) document, which is in its turn part of the European IPPC-regulation (European Integrated Pollution Prevention and Control). These BREF documents are top of the world regarding emission prevention and control, resulting in the European man-made fibre production being the cleanest production location in the world.
The effect of man-made fibres on water, be it pollution by pesticides, or irrigation effects, or whatever, is non-existing.