The Rann Government’s continuing failure to embrace storm water capture and re-use as a major part of water security strategies has been exposed by confirmation the desalination plant site’s operators have had to discharge storm water from its retention ponds.
The more recent of two controlled discharges happened on July 15.
“This says it all,” said Shadow Environment Minister Michelle Lensink.
“After heavy rains on site, the water collected at Port Stanvac has been dumped into the sea, where it will mix in with salty water and be sucked back up to be desalinated.
“I’m sure the irony of that is not lost on the locals,” Ms Lensink said.
Local residents noticed a significant plume of brown storm water in the sea adjacent to the desalination plant site north towards Hallett Cove Beach.
In an emailed response to concerns raised by Liberal candidate for Bright, Maria Kourtesis, site operator Adelaide Aqua confirmed that storm water collected on the site has been the subject of two separate controlled discharges.
“This is a classic example of how storm water gets dumped into the gulf while the science of collection and re-use continues to be ignored by the Rann Government,” Ms Kourtesis said.
While accepting Adelaide Aqua’s assurances that the water had been filtered before being dumped, Ms Kourtesis said residents still had concerns about the site’s operation.
Ms Lensink also reminded the government of concerns raised in a report last year into the site.
“The Environment Resources and Development Committee tabled a report in December 2008 into this plant in which we issued several warning bells to the government. We were not convinced by SA Water's evidence that they were taking the concerns raised by locally-based scientists seriously. In relation to the construction phase, we concluded that:
It is accepted that there will be considerable disturbance to the marine environment during construction, but the EIS has outlined strategies to address these issues with the use of management plans, and monitored closely to ensure disturbance is minimised as practicably as possible.
Adelaide Aqua’s email to Maria Kourtesis, 23 July
AdelaideAqua captures and manages all of the stormwater run-off from our site through redirection of stormwater flow into our two detention basins.
This stormwater is retained and recycled on site for use in dust control and moisture conditioning during earthworks.
The stormwater detention basins were constructed as part of Adelaide Aqua’s construction site establishment in April. One of Adelaide Aqua’s environmental responsibility commitments is to control construction site stormwater. In keeping with this commitment and to mitigate any potential risks, Adelaide Aqua sought a licence from the EPA at this time to undertake controlled discharges of stormwater only in the instance that a significant rain event could compromise the capacity of our detention basins.
Given the inclement weather we have experienced in the recent months the requirement for dust control has been low and thus two controlled discharges have been undertaken since April.
As part of the EPA licence conditions Adelaide Aqua is required to only discharge treated stormwater. As such prior to a controlled discharge a flocculent is applied to the basins to drop out all of the sediment. The treated water is then pumped via a soft hose to a naturally occurring discharge point. To preserve the existing discharge point, and not to exacerbate the existing and naturally occurring erosion, Adelaide Aqua has applied a geofabric silt layer for the water to pass down the cliff to the foreshore.
The second controlled discharge was on 15th July of 3ML of treated stormwater.