Over the next three months, Mullumbimby’s ageing gravity mains sewerage network will be prodded and poked more often than an in-patient at a teaching hospital.
But is the barrage of tests really worthwhile, or will it simply confirm what Council staff and a large proportion of the town already knows – that Mullum’s old gravity mains system is stuffed?
Former local sewage treatment plant operator Alan Dickens thinks so.
‘I don’t know what is to be gained by this,’ Mr Dickens said of the upcoming works.
‘They [already] have telemetry data on pump run hours, pump capacities, rainfall and inflow… so what more will this tell them?’
The test that really gets Mr Dickens’s goat (and the goats of more than a few other locals) is the plan to do another round of in-depth investigation with a camera.
This type of test is somewhat similar to a colonoscopy, with a small camera shoved along the drains to see if there are any obstructions, cracks or other assorted broken bits.
Mr Dickens said a similar test was undertaken in the early 2000s and confirmed, even that far back, that Mullum’s old clay pipes were not in a good way.
‘Those mains were tested with a camera back then and they’ve been smoke tested twice,’ he said, referring to the process of pumping smoke down into the sewerage pipes to identify leaks.
‘Internal reports were submitted at the time [which indicated] that the gravity mains were stuffed. I fail to see the point in camera testing the mains again – it will only show the same thing.’
Along with the camera testing, Byron Shire Council has hired a private company to closely monitor flow through the system using hi-tech sensors and to install a new rain gauge.
There will also be so-called ‘draw down’ testing – another method of determining how much water is flowing into the sewerage system from outside sources such as stormwater.
Council was unable to provide a figure for how much the camera testing would cost and there was no figure in the relevant Council documents to indicate this nor the cost of the tests overall.
While some locals see the testing as throwing good money after bad, others see it as a necessary step toward finally fixing the mains.
Duncan Dey, a civil engineer specialising in water and a member of Council’s Water, Waste and Sewerage Advisory Committee, said the current state of the mains needed to be confirmed so that funding could be allocated.
‘In terms of the camera testing, it’s been 15 years since that other testing was done. Things may have changed in that time,’ Mr Dey said.
‘In terms of the testing more generally, I think let’s just get it done and then we can take the next step.
‘I’m already convinced that it [the system] is stuffed – it’s a raw fact.
Status needs confirmation
‘But its current state needs to be confirmed otherwise we will never get any funding support from anywhere.
‘Even for Council to allocate its own internal funding it needs to have up-to-date data.’
Byron Council’s relevant officer is on leave and so no response was provided.
