North Head STP goes south

Sydney Water's plans to spend $220m upgrading the North Head sewerage treatment plant, on the northern side of the entrance to Sydney Harbour, have been rejected by IPART, a government pricing review body, and are almost certain to be deferred for two years or completely abandoned.

“There is a real chance that, without an upgrade, the off-shore disposal could become clogged and we could revert to the 1980s scenario of cliff face outfalls for months,” the Manly Environment Centre reports.

About 42% of Sydney's sewage, from as far away as Blacktown 40km west, comes to the treatment plant. Only about 30% of solids are removed by low-level "primary" treatment and there is no secondary or tertiary treatment. “The brew just gets pumped 4km offshore,” the Centre says.

North Head gets 75t of solids a day and “a heady mix” of industrial and other wastes. Sydney is the only coastal Australian city to dump its sewage into the ocean largely untreated. “Offshore ocean currents are said to disperse it quickly and the sea supposedly does the rest.”

For nearly two years, Manly community members have met Sydney Water to develop Project North Head for the period to 2020.

“We have made it clear that, while the community wants plant problems fixed to remove the risk of catastrophic failure, it requires an option that does not further entrench the ocean outfall and that leads to eventual elimination of the plant and the dumping mindset.

“Achievement of this goal needs long-term plans to reduce the inflow of sewage and stormwater, eg by treatment upstream, less stormwater infiltrating pipes, lower water usage and much greater reuse of treated water etc. Sydney Water refused to discuss issues other than the plant itself, so the whole project was dogged by disagreement,” the Centre said.

The best of a range of options would have increased the "solids" capture rate from 30% to only 65%. But there was still no secondary or tertiary treatment.

“Consultation has now ceased since IPART determined that Sydney Water hadn't made a sufficient case for its plans and refused permission to spend money on them.”

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North Head STP goes south

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