There used to be a joke among men in the washroom of the bar that they were simply recycling the beer! Some presentations at the Chartered Institution of Water and Environmental Management Annual Conference in London this week suggested that water recycling could become something much more than a joke.
All wastewater from Olympic Park, the site of the London 2012 Olympics, is recycled through a plant that the developer calls half sewage treatment plant, half drinking water treatment plant. The output water meets US Environmental Protection Agency standards for unrestricted use, including drinking water. However, due to UK regulations and anticipated public perceptions, the output water is used for irrigation of landscaping and for flushing of toilets at Olympic Park and is not used as drinking water. In fact, distribution and control systems have been designed to ensure that there are no cross connections between the recycled water and municipal drinking water services.
The Olympic Park water recycling project, which was originally implemented to allow the Olympic Games to meet aggressive water conservation targets, shows that the costs of recycling water are substantially below the costs of desalinating seawater and that the operating costs of a water recycling plant can be essentially the same as the operating costs of a similar scale of conventional wastewater treatment and drinking water treatment plant.
Another speaker suggested that public attitudes would make it very difficult to implement recycling of wastewater into drinking water in the UK but that conversations with residents of water scarce areas may lead them to agree on this type of solution for themselves.
The type of technology used at Olympic Park, which includes bio and membrane filters, activated carbon (subsequently found to be unnecessary), and chlorination, would also have application in food processing plants and other facilities which use large amounts of water and which are seeking to reduce their environmental footprint.
The Olympic Park facility is currently being expanded to deal with expanded quantities of wastewater from expanded post-Olympic use of the Park. As the presenter stated, it feels wrong to be using drinking water to flush toilets, so the water recycling plant can help address that aspect, even though the recycled water used for flushing does meet drinking water standards!
An excellent and easy to read paper on the Olympic Park water recycling plant can be found at http://learninglegacy.independent.gov.uk/publications/the-old-ford-water-recycling-plant-and-non-potable-water.php