Clariant uses water for a variety of purposes in the production of chemical products, resulting in the release of waste water effluents. At each site, production waste water is first subject to multistage chemical-physical pre-cleaning before being routed to biological waste water treatment plants, where it is micro-biologically cleaned. Water that is only used for cooling can be directly released into rivers because it is not contaminated. To prevent contamination of the intake water through undetected leaks in the cooling system, the cooling water and rainwater are constantly analyzed at the individual sites as an additional safety measure. If contamination is discovered, discharge into the rivers (or other receiving waters) can be prevented by various containment systems present on site.

The absolute and relative quantity of water used (in relation to production) have declined from 2014 to 2016. The amount of total waste water in 2016 was 13.2 million m³ or 3.23 m³ per manufactured ton of production compared to 13.7 million m³ or 3.60 m³ per t in 2014.

Clariant has reduced the chemical oxygen demand (COD) - the measurement for the degree of waste water burdened with organic substances - in all the waste water treatment plants by nearly 70 % from 2005 until 2016. Consequently, the fees and production costs were reduced.

Only small amounts of heavy metals remain in the waste water at Clariant’s individual sites. The values are partly based on the concentrations that are at or below the detection limit. The waste water discharged by Clariant is largely cleaned and does not affect the quality of the receiving water. Thus, Clariant has achieved very high standards in waste water treatment and water purification within a very short period.