15 February 2018
With the environmental assessment of the Merimbula Sewage Treatment Plant (STP) Upgrade and Ocean Outfall project continuing, further dye dispersion tests are planned for Merimbula Bay next week.
Thursday (22 February 2018) has been earmarked as the preferred day at this stage, however due to the nature of the testing, favourable weather and sea conditions are required. Merimbula Bay will be open and safe for all water users during the tests.
Council’s Water and Sewerage Services Manager, Jim Collins, said the dispersion tests represent a key element of the hydrodynamic modelling for the project and will involve consultant hydrologists releasing a harmless, bright red fluorescent dye called Rhodamine into the water at up to four locations, including Haycock Point and in the middle of the bay.
“The information received from these tests will show the dispersion rates and travel times of waterborne materials in the bay, and will help our designers determine the best location for the placement of the deep water ocean outfall,” Mr Collins said.
“Rhodamine, which will disperse rapidly, follows the pathways of currents closely and has a low impact on water quality. It will be used to measure how long it takes the currents to move water between predetermined sampling sites, with the testing set to take a few hours in each location.
“We undertook a similar process in September 2017 and this work will further inform our planning.
“Council is acting on advice from the NSW Environment Protection Authority and also local community concerns, that the existing beach-face outfall at the Merimbula Sewerage Treatment Plant is not sustainable,” Mr Collins said.
To follow the progress of the project visit www.begavalley.nsw.gov.au/merimbulastpupgrade.
For more information contact Council on (02) 6499 2222.
Photograph: Further dye testing is planned to occur in Merimbula Bay next week.