Environmental Protection

Water Consumption and Usage

Important information on "Environmental Protection" can also be found in our Annual Report.

Covestro takes a holistic view of water as a resource: we account not only for our water consumption and the associated problems of water scarcity and quality, but also the wastewater we generate. This is underscored by our “Corporate Commitment on Water” issued in 2017.

For our production sites, the availability of and access to clean water is vital. In many regions of the world, however, this is increasingly at risk. As part of our voluntary commitments regarding water, in 2017 we therefore initiated a risk assessment of our production sites covering water availability, quality and accessibility. During the reporting year we updated our risk-based approach and implemented it at further sites. Based on their share of water consumption, a risk-based approach to water has already been introduced at 96% of sites that are currently exposed to a high risk of water stress. Water stress includes water scarcity as well as other factors such as water quality and access to water. By analyzing local water management at sites, risks can be spotted at an early stage and potential for improvement can be identified. 15% of our total water consumption is at sites located in current water stress regions.

Use of Water in 2018 (million cubic meters)1

Use of Water in 2018 (million cubic meters) (graphic)

1 Differences between the volumes of water drawn and discharged can be explained in part through unquantified evaporation, leaks, water used as a raw material in products, and condensate from the use of steam as a source of energy.

2 E.g. rainwater

3 Also includes water for irrigation purposes

4 Total from production processes, sanitary wastewater, and rinsing and purification in production

At 265 million metric tons, total water consumption in the Group is slightly higher than in the previous year. 80.2% of water is once-through cooling water, and consequently accounts for most of the water used by Covestro in 2018. This water is only heated and does not come into contact with products. It can be returned to the water cycle without further treatment in line with the relevant official permits. The total volume of once-through cooling water was 213 million cubic meters in the reporting year.

Some of the water used can be recycled in various ways. For instance, recycled water can be used again in the same process multiple times, e.g. for cleaning or cooling purposes. It is also possible to reuse water from upstream processes in subsequent steps. As a result, corresponding amounts of fresh water are saved every year. In the reporting year, the percentage of reused water rose by 37.1% to a total of 5.1 million cubic meters, due in part to the use of a reverse osmosis process in Cuddalore, India.


Our goal is to minimize emissions into wastewater. These emissions are largely dependent on our production volumes and the current product portfolio.

The volume of process wastewater increased year-on-year by 3.3%. The proportion of process wastewater purified at a wastewater treatment plant operated by Covestro or a third party amounted to 71.5% worldwide. Following careful analysis, another 28.3% was categorized as environmentally safe and returned to the water cycle. The remainder (around 0.3%) was disposed of mainly through incineration. In the reporting year, the percentage of evaporation losses rose by 62.8% to a total of 11 million cubic meters. Among other things, this is due to higher production volumes at Antwerp, Belgium.

Total organic carbon (TOC) emissions into wastewater decreased by 6.0% compared with the previous year. The volume of phosphates discharged into wastewater was also down, by 21.6%. The main reason for this is normalization of wastewater treatment at the Kaohsiung site in Taiwan. By contrast, the amount of nitrogen compounds discharged rose by 12.9%. This was due to a lengthy maintenance and cleaning- related standstill at a denitrification plant at our site in Baytown, USA. Such maintenance operations fall within the scope of the existing operating license. The volume of inorganic salts introduced into wastewater fell by 4.9%. Likewise, the volume of heavy metals emitted fell by 8.3% during the reporting year.

Emissions into Water (1,000 metric tons p.a.)











1 Total organic carbon

2 Chemical oxygen demand, calculated value based on TOC values (TOC x 3 = COD)
















Heavy metals





Inorganic salts










Work on the “Re-Salt” joint project aimed at recycling salt-laden industrial process water, which was outlined in the 2017 Supplementary Report, continued in 2018. The project is scheduled to run for three years and is sponsored by the German Ministry for Education and Research (BMBF).

GRI/Global Reporting Initiative
Guidelines for the preparation of sustainability reports by companies, governments and non-governmental organizations (NGOs)