Reducing water pollution
Clean water is essential to our business and to the habitats and communities around us. It is our responsibility to reduce as far as possible the polluting power of the water that leaves our operations.
By 2015, our target is to reduce the polluting power of wastewater (measured in biochemical oxygen demand or ‘BOD’) by 60% against a 2007 baseline. This year, we achieved a 9.0% reduction. Despite this reduction, however, overall there has been an 11.2% increase in the BOD polluting power of wastewater since 2007.
Nonetheless, we have cause for optimism in 2013. Our Cameronbridge distillery in Scotland, where we make Tanqueray gin and grain whisky for Johnnie Walker, Buchanan’s and Windsor, was responsible for 60% of our BOD in 2012. In the last quarter of 2012, the distillery’s new bio-energy plant began to produce positive results, reducing BOD by 34% compared to the last quarter of 2011. With the plant becoming fully commissioned during the next financial year, we hope to achieve significant BOD reductions and be on track to meet our 2015 target.
Across all our operations, we are concentrating on ensuring that products such as yeast and spent grain are eliminated from our wastewater and instead used for positive purposes. We are also seeking ways to reduce the use of brewing filtration process aids like kieselguhr. At our Ogba brewery in Lagos, Nigeria, for example, we implemented a new filtration system which eliminates kieselguhr, with consequent benefits for wastewater. We are looking to replicate this new technology at other sites.
Globally, our facilities handle and treat effluent in three ways:
- On-site effluent treatment facilities, where anaerobic and/or aerobic microbial growth reduces BOD
- Direct routing to off-site third-party municipal treatment facilities, where anaerobic and/or aerobic microbial growth reduces BOD
- Direct disposal to the environment, where wastewater is discharged under licence and local regulations and relies on dispersal to minimise impacts.
Water discharge by quality and destination (2012)
|The immediate receiving medium after leaving Diageo site ||As a % of total Diageo effluent volume ||The % of the final BOD to the environment
|Wastewater polluting power (BOD/kt)
|Region ||2007 ||2010 ||2011 ||2012
|Latin America and Caribbean
Our new £65 million bio-energy facility at Cameronbridge in Scotland doesn’t just generate renewable energy...