A bus depot, rainwater harvesting and a concrete-covered site may not be obvious ingredients to mix, but in Cardiff they’ve been put through the refurbishment blender to produce an award-winning cocktail.
The Sustainable Water Industry Group’s annual Awards highlight inspiring ways of using water wisely and this year the Cardiff Bus scheme is a winner in the Non-residential Retrofit category. The scheme was designed by Rainharvesting Systems Ltd, in partnership with Natural Power UK, and brings the total number of award-winning schemes that it’s been involved with this year to three – very satisfying for the UK’s longest supplier of rainwater harvesting systems.
Installed as part of a refurbishment earlier this year, the system collects rain falling onto an area of the depot’s roof, cleans it using ultra-violet disinfection and then stores it in a 26,000 litre tank. At the moment, more than 200 buses are washed everyday using water collected in this way. The site’s concrete surfaces presented a particular challenge for designing the system as the storage tank holding the collected rainwater is usually stored underground – obviously not possible here. So a special tank was designed to sit above ground and protected from freezing during winter by a combination of heavy duty insulation sandwiched between the inner and outer tank walls and trace heating.
In the first 5 weeks of operation, 150m3 of rain was used instead of mains water – not only more environmentally friendly but saving the company money on its water bill. Win-win all round!
