First stage of Merimbula's $30 million ocean outfall

A $3.264 million consultancy contract has been awarded to AECOM for a design concept and environmental impact statement for the Merimbula ocean outfall.

It is the beginning of what will undoubtedly be a long process to build a better way of disposing of 75 per cent of treated waste from Merimbula sewage treatment plant.

The Merimbula ocean outfall, costed at around $30 million, has been listed as state significant infrastructure. It will include sewage processing systems and a deep water ocean outfall transfer pipe running from the treatment plant, mainly underground, to a discharge point, being a submerged diffuser located on the seabed up to 6 kilometres away. Work will also include installation of pumping equipment and the decommissioning of existing exfiltration ponds.

Council’s director transport and utilities Terry Dodds said it was the next stage of a long running process.

“ We must do this, the EPA have asked us to do it. It’s an expensive process but we must do it,” Mr Dodds stressed.

Speaking at the council meeting on Wednesday, March 15 when the matter was being discussed, councillor Sharon Tapscott said that the consultancy was something that had to take place “as expensive as it is” if council wanted to put it’s hand out for money.

And there is no doubt that council will have to do just that. When asked by councillor Mitchell Nadin whether cost estimates would vary, Mr Dodds replied that there was “every chance” they would.

However until a design concept has been produced council does not know what exactly has to be built.

Mayor Kristy McBain threw her full support behind the proposed works saying it was unacceptable to have a beach outfall.

“An outfall will have to be used because we can’t use 100 per cent of our treated water. We should be aiming for reuse but when we can’t it has to go somewhere,” Cr Kristy McBain said.

It was something that Mr Dodds emphasised in his report.

“It should be clearly understood there is no prospect of a simple reliance on beneficial reuse as the solution to the effluent management challenges at Merimbula. A viable, sustainable disposal option is required,” he stated.

It should be clearly understood there is no prospect of a simple reliance on beneficial reuse as the solution to the effluent management challenges at Merimbula. A viable, sustainable disposal option is required.

Terry Dodds, director transport and utilities Bega Valley Shire Council

Councillor Tony Allen has followed the issue for many years and called it a big step forward.

“I hope we’re lucky enough to get the money, not just for Merimbula, but for the environment,” he said.

Cr Fitzpatrick called it a “big ticket item”.

“We’ve got a long way to go and have got to go to the state government but I can’t see how we can’t get the money for it,” Cr Fitzpatrick said.

Part of the consultancy project will be the preparation of an EIS which will assess the economic implications of the STP upgrade and deep water ocean outfall. A major component of the EIS process will be community and stakeholder consultation and communication, council said, adding that significant allowance had been made for this aspect of the project.

The Merimbula Sewage Treatment Plant (STP) treats sewage from Merimbula, Pambula, Pambula Beach and South Pambula to an advanced secondary standard.  Approximately 75 per cent of the effluent produced is disposed via the existing ocean outfall across the beach or to the exfiltration ponds in the dunes opposite the STP. Approximately 25 per cent is used to beneficially irrigate the Pambula-Merimbula Golf Course and Oaklands Farm.

The existing methods of effluent disposal are unsustainable. The beach face ocean outfall fails to meet community expectations and NSW Environment Protection Authority (EPA) environmental objectives. The dunal exfiltration ponds are limited by groundwater level impacts and long term sustainability issues.

The deep water ocean outfall has been established as the effluent disposal option that is likely to provide the greatest relative environmental benefit through improving receiving water quality and ecology, having the least construction impacts and operational greenhouse gas emissions and providing the greatest preservation of Aboriginal cultural heritage, aesthetics and recreational amenity.