Clean water is an increasingly precious resource, and there are huge inequities in water use around the world; for example, 700 L for domestic use per individual per day in the US, compared with 7 L a day in Senegal. Meanwhile, according to the World Water Council, more than 1 billion people lack access to clean drinking water while 2.6 billion do not have access to adequate sanitation. However, the main consumers of water are industry and agriculture. The amount of water used by industry, including pharma and biotech manufacturing, amounts to 23% of the world's supplies on average, which ranges from 5% to as much as 80%, depending on the nation and its level of development.

Water footprint

Susan Aldridge

The pressure is on to save water in all areas of life. This means not only fixing that dripping tap, but making sure that industries use the smartest technologies and best designs possible to optimize water use.

These efforts could learn from a relatively new concept known as water footprint, which has been introduced by Arjen Hoekstra and Ashok Chapagain of the University of Twente (The Netherlands). Water footprint is similar to the idea of carbon footprint, and the two are connected because energy is used to produce purified waters, such as those used in pharma and biotech manufacturing, and to process wastewater effluents. The water footprint is defined as the amount of freshwater a nation uses in production of goods and services, including its medicines. The total global water footprint is, on average, 7450 Gm³/year, which is equivalent to 1240 m³/year/head, varying from 2480 m³/year per head in the US, to 700 m³/year per head in China. These figures include the volume of industrial water drawn both within and outside the nation.

Key Points

Water footprint is closely linked to the concept of 'virtual water', which is the water used to produce a good or service (according to Hoekstra and Chapagain, the virtual water content of a microchip is 32 L, and 8000 L for a pair of shoes).¹So far, this concept of water 'price' has mainly been applied to agriculture. Industrial products are said to have an average virtual water content of 80 L per dollar used in their production, which varies from 100 L in the US, to 50 L in Germany and The Netherlands, and only 10–15 L in Japan, Australia and Canada. These concepts have not been widely applied to the pharma and biotech industry.

Pharma's needs

Pharma and biotech industries rely on water — and expensive purified sterile water at that — for processing, as their products are intended for human consumption. Biologics manufacturing relies on water even more because microbial and mammalian cell culture require a carefully controlled aqueous medium for productivity, and water quality and availability are key issues. If this industry is to grow, it must get the water it needs, and this can be a major contributing factor in determining the location of a plant. A large facility uses millions of litres a day and cannot afford to be affected by interruptions in supply. For instance, Amgen (CA, USA) had extensive discussions with the local water authority in 2004 regarding whether enough water would be available to manufacture its drug Enbrel at its Rhode Island plant in the US. The talks resulted in the company introducing many water conservation measures in-house to safeguard its supplies. This was not just, the company said, self-interest, but about trying to set an example as a corporate citizen.

Water is also a necessity for biotech industries for downstream processing, formulation and cleaning, with the latter application accounting for approximately 60–80% of water usage in a manufacturing plant. Energy and costs of producing the different grades of water, which are used in the operations that go into making a biological medicine, must also be considered. According to Simon Routledge, cGMP production manager at the UK's National Biomanufacturing Centre in Speke, the water requirements of a plant largely depend on the dosage form and purity requirements of the final product, and this is also true for pharma. If the product will be introduced orally, water quality requirements are not as high as those required for a parenteral product, Routledge explains.