Could Making Beer From Sewage Save Us From The Drought?

[Photo Credit: Vince C Reyes]The historic drought in California and other U.S. states challenges us to rethink the way food production and consumption shapes our available water supply. To that end, one adventurous brewing club, The Oregon Brew Crew, collaborated with Oregon’s water utility, Clean Water Services, to brew beer from waste water. This comes as part of the water utility’s initiative to make better use of recycled water. As beer is 95% water, we could potentially save significant volumes of water through this less glamorous route.^1 To be clear, the brewers did not make beer straight from water entering out of the toilets and sewers of Oregon. Clean Water Services provided the brewers with “ultrapure water” for making their beer. Ultrapure water is made from water that is purified using the most advanced water treatment methods available. Ultrapure water is not new, but is normally not used for brewing. It is traditionally used for generating water for electronics and pharmaceuticals production, scientific research, or any other application where water must be free from as many contaminants as possible. To generate ultrapure water, Clean Water Services combines traditional wastewater treatment with more advanced methods. For this process, sewage is first cleaned using traditional wastewater treatment, which includes screening, sedimentation, biological treatment, and disinfection. After this step, the sewage is fit to be released to lakes and rivers, but gets a deeper cleaning through more advanced methods. In the case of the water used by the brewers, Clean Water Services uses a three-step process of Ultrafiltration, Reverse Osmosis, and Enhanced Oxidation to produce their ultrapure water. The water is first subject to Ultrafiltration and Reverse Osmosis. These processes work like a kitchen sieve as they push water through small pores in a barrier to separate water from different molecules. While both Ultrafiltration and Reverse Osmosis use similar physical separation mechanisms, they vary in the products they can remove from water because of their differing pore sizes. Ultra-filtration can be used to remove particles as small as viruses and bacteria (0.005 – 0.5 μm), while Reverse Osmosis uses finer pores, which can remove even smaller molecules like herbicides, pesticides, salts, and metal ions (0.0001 – 0.001 μm) (Figure 1).