Desalination plant payment on ice

Posted by: Saving Water SA (Cape Town, South Africa) – partnered with Water Rhapsody conservation systems – 07 April 2011

The consultants and civil engineers responsible for Plett’s non-functioning desalination plant should explain why it was not working, and possibly their payment should be withheld, Bitou mayor Lulama Mvimbi said last week.

Test intake wells are visible in the lagoon in front of the Beacon Island resort. Photo: Janine Oelofse

Asking who was to blame for the forced shutdown of the new R32-million plant less than three months after it was commissioned, Mvimbi said in the same way that council was questioned about services which clients were not satisfied with, Bitou should “also play hardball” with the contractors hired for the desalination project.

“They should sort the problems out” before they were paid, Mvimbi said. Addressing the Bitou mayoral committee, Mvimbi questioned the claim by town officials that the desalination plant was in “pilot project” phase.

“We can’t just say that,” he said, adding that the assertion suggested the R32-million had been wasted – R12-million of which had come from ratepayers and the rest from provincial government funding. Mvimbi said all the consultants and contractors would be called to a meeting with Bitou officials to explain themselves and chart a way forward.

Municipal officials earlier said the desalination plant was shut down on March 1 after the mouth of the Piesang River closed, drawing criticism from environmentalists who reminded Bitou that they had voiced their opposition to the municipality’s choice of location for the plant on the Piesang estuary.

When the plant was first mooted, Plett conservationists said they were concerned that the emergency drought regulations were being used to fast-track the project and dodge the legal requirement for an environmental impact assessment in advance.

Bitou said the shutdown became necessary after the estuary’s surface level dropped below the environmentally viable threshold.

“To avoid potential degradation of the Piesang estuary ecosystem, Bitou Municipality has elected to discontinue abstractions until specialists can be consulted and the required (retrospective) environmental monitoring systems are up to speed,” Bitou said in a statement.

The biggest problems encountered have been with the abstraction of sea water for processing by the plant.

The plant’s intake wells were moved to the Piesang estuary after Robberg Beach was found to be unsuitable, but after the river mouth closed, the abstracted water became increasingly fresh, lacking the salt levels required for the desalination process.  Bitou services and infrastructure development manager Phumla Ngqumshe said the “pilot phase monitoring” would be rerun “once the estuary levels have stabilised”.

She said a new brine recycling system would be put in place which would increase the salinity of the feed water and reduce intake from the estuary.

This approach had been chosen on environmental grounds in preference to artificial recharge of the estuary with salt water or forcing open the river mouth to facilitate tidal recharge.

Garden Route Media
By: Neil Oelofse

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