This has helped ensure that there were no major breaches since 2000 against Sydney Water’s Sewage Treatment System Environment Protection Licences.
During 2009–10, Sydney Water completed work at Bondi and North Head Sewage Treatment Plants and has work underway at Winmalee and Wollongong Sewage Treatment Plants. Plans to upgrade the Warriewood plant are being prepared.
The Bondi plant serves about 500,000 people. From 2007, additional sludge thickening facilities were built to enable production of more biosolids to be used as compost in agriculture. These were finished in September 2009.
The project’s construction approach ensured there was little impact on the environment and community. Concerns such as truck movements, vibration from tunnelling, water quality and odour controls were quickly addressed. After construction, nearby parks and embankments were upgraded, including constructing a new public footpath and refurbishing heritage sandstone steps.
At North Head Sewage Treatment Plant, a $150 million improvement project was completed in December 2009. It will ensure reliable plant performance and ongoing protection of water quality, in line with environmental protection standards, through to 2023. The plant serves a population of over one million people and treats about 300 million litres of flow a day.
The first hydroelectric plant in Australia to generate power from treated wastewater was built at the North Head plant. Together with cogeneration – where methane produced during wastewater treatment is turned into green energy – the plant now generates about 40% of its own power during normal operations. A recycled water facility also generates 95% of the water used on site.
To celebrate the completion of the $150 million North Head Sewage Treatment Plant improvement project, Sydney Water opened the plant to the community. On 1 May 2010, about 80 visitors toured the plant and saw the challenges faced above and below ground during construction.
At the Winmalee plant, structural repairs will be completed by the end of 2010. As the plant now services the upper Blue Mountains, its increased reliability is an important community concern.
Work on improvements, to produce more biosolids at the Wollongong plant, is progressing, alongside work to reduce odours. This is due to finish in late 2010.
Sydney Water is focusing on controlling odour emissions from plants that are near growing residential developments. In addition to the Wollongong plant, odour control work will begin in early 2011 at Malabar and Cronulla. Odour control work at St Marys is also scheduled for 2010–11.
Repairs on 12.7 kilometres of the North Georges River submain were completed at the end of June 2010 at a cost of about $65 million. The sewer was repaired between Fairfield and Arncliffe, with work across multiple sites along the route. Most of the work was high-risk, with live wastewater flows. At some locations, the work was up to 30 metres below ground level.
Major construction works for the Glenfield Liverpool Effluent Diversion Scheme are underway. The scheme will enable Sydney Water to transfer treated wastewater from Glenfield and Liverpool Sewage Treatment Plants for use in the private Rosehill-Camellia Recycled Water Plant. Work will be completed in November 2010.
During 2009–10, lining work to strengthen wastewater carriers at Adderley Street in Lidcombe was finished. The remaining unlined sections of Berkeley Carrier, a major wastewater main at Wollongong, were also completed.
The reinforced concrete pipeline at Wollongong was relined with Panel Lok spiral wound PVC liner. Fifty metre lengths of Panel Lok were fed into the spiral-winding machine, which locked the liner in place. Grout was then inserted between the liner and the pipe. Use of the Panel Lok machine meant that fewer workers were needed and they spent less time in confined spaces.