Throughout the world, we focus on using water resources sustainably. Our commitment here includes keeping water consumption as low as possible in areas where water is scarce and reducing or preventing emissions to water. In 2011, we reviewed water consumption in regions susceptible to water shortages (water stress areas). Five of our larger production facilities were located in areas that fall under the highest risk category. These facilities account for around 5 percent of total water use at Linde. We set ourselves a new goal. By 2013, we want to have strategies for sustainable water management in place at sites located in water stressed areas. We provide regular reports on our water needs and consumption. In 2011, we again participated in a public survey on water consumption conducted by the Carbon Disclosure Project.

Water balance 2011 (graphic)
1 Due to e.g. evaporation, total water input may deviate from output. Waste water volume is
reported as required by regulators. Unpolluted water volume is estimated.

Water use

In 2011, The Linde Group used approximately 288 million cubic meters of water worldwide (2010: 255 million cubic metres). Around 97 percent was drawn from surface water supplies and groundwater reserves. Around 3 percent of the water used is drinking water. More than 85 percent of the water we need is used for cooling. As the majority of this cooling water is not contaminated, it can be returned to the water cycle with no further treatment at a temperature that does not pose any risk to the surrounding ecosystem. At around 43 million cubic metres, the volume of water consumed by Linde was down slightly on the previous year. This water is primarily used in the manufacture of our products, for steam production and in our office buildings.

Of total water consumed in 2011, around 33 million cubic metres was process and industrial water (2010: 32 million cubic metres). Well over half of this water was used in our air separation plants. In addition to once-through systems, we also use water circulation systems to recycle water several times. Only a small percentage of this water needs to be replaced in the process depending on water quality and the technical equipment at each plant.

Emissions to water

Where necessary, we purify the waste water from our production and sanitary facilities either by using our own treatment systems or by sending it to municipal or industrial plants. In 2011, we reported to regulators around 8.1 million cubic meters of waste water at our locations throughout the world (2010: 8.4 million cubic metres). To assess our impact on water quality, we measure the amounts of phosphates, nitrates and organic compounds we release. Small amounts of heavy metals, for example, may be present in the waste water from our air separation plant cooling processes. These are present in the metal pipes and their protective coating and are released by corrosion. We use phosphates as anti-corrosion agents here.

Water emissions









The Linde Group












in tonnes










We monitor compliance with local regulatory requirements worldwide and report our data for all locations legally obliged to report emissions. Increase or decrease of emissions to water in 2011 do not necessarily represent business trends but result from e.g. site maintenance or changes in plant operating modes.

Chemical oxygen demand (COD)









Biochemical oxygen demand (BOD)



























Making water cleaner

Our water solutions for customers help to improve the quality of untreated water and drinking water. We also offer solutions to optimise the treatment of waste water. Our SOLVOX® OxyStream solution, for example, is a particularly energy-efficient oxygenation system for the fish farming industry. The new system can work at lower pressures than conventional concepts as it is smaller and mixes gas and water highly efficiently. This cuts the energy required to power the pumps by over 50 percent, which in turn reduces costs and emissions for our customers. The system has already been successfully installed at over 30 land-based aquaculture sites.

Within assurance scope

Key figures comparison

Global Compact

This page contains information that is relevant to the ten principles of UN Global Compact.

© The Linde Group 2012