Desalination plant will have no adverse affect on communities in Nanarup or Sandpatch, says Water Corporation

The desalination plant mooted by the Water Corporation for either Nanarup or Sandpatch will not adversely affect either community, the company’s Great Southern regional manager has vowed. Speaking to an audience of about 100 at Lower Kalgan Hall on Wednesday evening, Adrian Stewart said the plant would be about “four sea containers” in size and would be barely visible. He also said that should Nanarup be chosen, the beach would need to be closed only briefly while the Water Corporation drilled underneath it. “We have not got to the stage of detailed designs, but we would expect the plant to be about the size of four sea containers,” he said. “There are people around here who have sheds bigger than that.” Speaking after the meeting, Mr Stewart said the overall footprint, including tanks, would be 2-4ha and surrounded by vegetation. “At Nanarup it’s unlikely anyone would be able to see it, though it would probably be a bit more visible at Sandpatch,” he said. “There will be noise from motors and pumps, but we will try to minimise that.” The meeting on December 10 was the third of Water Corporation’s public consultations. Mr Stewart said the on-land facility would likely be 200m from the shoreline and the company was proposing to use horizontal directional drilling to install a pipeline under the seabed. A presentation by Ryan Alexander, of Perth consultancy RPS, modelled the likely behaviour of the brine which would be discharged back into the ocean. He said diffusers placed where the ocean was 15m deep would disperse the brine, leaving the water almost at normal salinity within 50m. The challenge, he said, was to disperse the “final teaspoon” of salt, although he added that the model had made worst-case assumptions and based its results on untypical still, calm conditions. Water Corporation has a six-point assessment plan which it will use to weigh up the options for each site. The criteria being used are social, environmental, technical, delivery and operation, economic and regulatory. Mr Stewart said each would be given equal emphasis with the chosen venue likely to be announced in February next year. The choice between Sandpatch and Nanarup was “still 50-50”, he said. “There won’t be an ongoing impact to the Nanarup beach, there would be nothing constructed or left there, although there might be an exclusion zone for a short period of time during construction,” he said. “We are looking for the best site, not the most cost-effective and, except when we are tunnelling, we would expect there to be no impact on the community at all.” The proposed plant would ultimately have a maximum capacity of six gigalitres a year — about 16.4m litres a day — which could cope with Albany doubling its population over the next three decades. A largely sceptical audience challenged the brine modelling as being a “snapshot” and worried that currents would bring brine back onto the beaches. Audience members also pointed out there had been minimal adverse reaction to Sandpatch being under consideration and suggested it would be the ideal spot. Mel Michael, of Friends of Nanarup, said the brine modelling had been based on “a mix of assumptions and existing general data”. “It was good to get detailed modelling, but we will continue to press for transparency,” she said. “We don’t believe due diligence is being done and we feel there is a loss of trust. “There was also a good point made in the audience about this area being a jewel in the crown — would they put a desalination plant on Cottesloe Beach? “We are evaluating our next steps and will keep asking questions.”