Kurnell – Sydney
Desal Plant Sucks in Sewage (November 7 2010)
http://www.dailytelegraph.com.au/news/desal-plant-sucks-in-sewage/story-e6frewt0-1225948832232“SYDNEY’S $1.9 billion desalination plant is sucking in sea water containing 400 times more sewage bacteria than dam water. In a major shock, the first Sydney Water quarterly report on desalinated water produced from these raw supplies found it contained E. coli bacteria and failed to meet Australian guidelines for drinking water. The report, published on the Sydney Water website, revealed the Kurnell facility was the only one of 10 Sydney filtration plants not
to get a “100 per cent” pass during the September quarter…
Tests showed that Kurnell’s raw water samples contained as many as 390 bacteria per 100ml, with an average reading of 22… A Department of Planning assessment of the desalination plant, published in the lead-up to its construction, acknowleged concerns that “intakes may draw in the discharges from [sewage treatment plant] outfalls, effectively meaning the plant would be recycling treated effluent”.
The document calculated the Potter Point outfall, where treated sewage pours straight from the cliffs into theocean, could impact on the Kurnell plant up to 26 per cent of the time…”
“THE current off Sydney’s $1.9 billion desalination plant takes sewage from an outflow only 2.5km away directly pastits intake about a third of the time. The environmental study used to justify the Kurnell plant’s location relied in part onan assumption that because the prevailing current runs south, there would be little danger of E.coli from the sewage being sucked into its inflow, to the north. But CSIRO scientists who monitor the current yesterday told The Australian
that it sweeps north about a third of the time, and yesterday was one such day. It has been established that on some days, the amount of E.coli in intake water is more than double the guidelines for safe bathing…As reported yesterday, professor of infectious diseases and microbiology at the Australian National University, Peter Collignon, has claimed poor water quality at the Kurnell plant could create a public health disaster if filtering systems were ever to fail.
..However, Ms Schott’s claims are contradicted by her organisation’s most recent quarterly drinking water report. The report showed that of 53 samples collected between 1 July and 30 September, the maximum number of E.coli organisms per 100ml of unprocessed water was 390, with a minimum 1 and an average of 22. The annual average was 16.”
DESALINATION plants built near sewage outfalls are not protected by the natural purification that occurs in dams. This is because the water is not stored long enough for the bugs to die. In the wake of concerns about the quality of Sydney’s drinking water, experts told The Australian yesterday that the short distance between the Kurnell desalination plant and the Cronulla sewage outfall had the potential to diminish water quality. Parasites such as E.coli, cryptosporidium and giardia are killed by prolonged exposure to light, oxygen and temperature fluctuations, University of NSW water quality expert David Waite told The Australian.
“If they’re exposed to conditions different to what they’re used to then they won’t last long. And that’s the case in dams,” Professor Waite said. As reported on Wednesday, cryptosporidium can survive in seawater for up to 12 weeks. But the time taken for sewage discharged from Sydney’s Cronulla outfall to reach the Kurnell desalination plant’s intake, just 2.5km away, could be as little as two hours, CSIRO oceanographer David Griffin said…”