Water Journal : Water Journal May 2014
WATER MAY 2014 20 Industry News ENVIRONMENTAL INNOVATION RECEIVES INTERNATIONAL HONOURS Contact Energy's Wairakei bioreactor in New Zealand has been awarded honours at the internationally recognised 2014 IWA Asia Paci c Regional Project Innovation Awards in Singapore. Jointly developed by Contact Energy and Beca, the bioreactor is a world- rst solution to improve the quality of water that is discharged from the iconic Wairakei geothermal power station into the Waikato River. "I'm immensely proud of our bioreactor," says Contact Energy CEO, Dennis Barnes. "As a world- rst it's great to see this example of Kiwi ingenuity recognised at an international level." "To work with Contact Energy from the beginning, developing and testing innovative concepts through to the design and construction of the Wairakei bioreactor has been immensely rewarding for the Beca team," says Beca CEO, Greg Lowe. "This is another great example of New Zealand talent delivering world-class project outcomes." The Wairakei bioreactor was developed to reduce hydrogen sulphide (H2S) discharges from the Wairakei geothermal power station to the Waikato River. This was identi ed through a 10-year program of environmental and technical studies which examined the environmental impacts from the ongoing operation of the power station. These studies showed that H2S levels in the Waikato River downstream from the Wairakei power station exceeded accepted water quality guidelines. Harnessing the power of billions of naturally occurring bacteria endemic to the Waikato River, the bioreactor was developed as a treatment facility for the breakdown of H2S in the cooling water. The bioreactor is designed around a large network of almost 400 kilometres of pipes that create an environment for the bacteria to live and grow. To date, the bioreactor is reducing around 85 per cent of H2S in the cooling water discharges, which is equivalent to a reduction in H2S discharge levels of almost 8,000 kilograms per week. It is also on track to achieving the August 2016 milestone of an overall reduction of 95 per cent. In creating this solution Beca engineers used several innovative engineering techniques, including: a tubular bio lm reactor design consisting of 1900 parallel polythene pipes; excavated soil and pumice from the site was mixed with concrete to hold the 378 kilometre-long polythene pipe eld in place, saving considerable costs; and a syphon con guration for the bioreactor hydraulic design lowers the pumping head to minimise power usage and also contributes to signi cant cost savings. The IWA Innovation Awards is a prestigious global competition that recognises and celebrates innovation and excellence in water engineering projects around the world. The Wairakei bioreactor was also awarded the 'Energy Project of the Year' and 'Environmental Excellence' awards at the 2013 Deloitte Energy Excellence Awards (NZ). It received the 2013 New Zealand Engineering Excellence Award in the Chemical, Bio and Food category and is a current nalist for the INNOVATE NZ Awards of Excellence. MORE THAN 80 DAMS IN 80 YEARS FOR THIESS Celebrating 80 years of operation, one of Australia's leading construction, mining and services contractors, Thiess, is proud to announce its 84th dam project. Melbourne Water has awarded Thiess a contract to upgrade the Greenvale Reservoir, an important water supply source for the north- western and western suburbs of Melbourne. The 27,500 million litre storage was constructed in 1971 and is Melbourne's most urbanised large dam located just 20 kilometres from the CBD. Thiess has been engaged to upgrade the dam wall to ensure Greenvale Reservoir continues to serve the growing population of Melbourne both now and into the future. Thiess Victoria General Manager Rod Heale said Thiess is delighted to be undertaking such an important project in its 80th year. "Thiess has built twice as many dams as any other contractor in Australia and we are very pleased to be extending our strong relationship with Melbourne Water on the Greenvale Reservoir upgrade," Mr Heale said. The project is scheduled for completion in mid-2015. CORALS DON'T LIE: RISING SEA LEVELS AND TEMPERATURE DATA REVEALED AIMS scientists, together with a team from the University of Western Australia, CSIRO and the University of San Diego, have analysed coral cores from the eastern Indian Ocean to understand how the unique coral reefs of Western Australia are affected by changing ocean currents and water temperatures. The research was published in the international journal Nature Communications. The ndings give new insights into how La Niña, a climate swing in the tropical Paci c, affects the Leeuwin current and how our oceans are changing.
Water Journal April 2014
Water Journal June 2014