Alan Dickens, Brunswick Heads
Byron Shire Council’s (BSC) Water and Recycling are now saying they don’t have plans of their sewer gravity mains.
As a former sewer operator, we spent ten years supplying information to the Mullumbimby Council office to generate maps of the gravity mains system.
There is a significant library of maps that were generated and stored. I and other staff used them over the years.
The Water, Waste and Sewer Advisory Committee meeting (WWSAC) of January 30 were informed of the relining of the Mullumbimby gravity mains by a company called Interflow. This company relined a sewer gravity main in Blundel Lane in Brunswick Heads as a test case. This main was just over a metre deep and laid in the sand, which was bone dry. The gravity mains of concern in Mullumbimby, as described in an earlier article by hydraulic engineer Duncan Dey, are the deep gravity mains. They are laid between four and six metres deep, in clay that is permanently wet. Council would want a guarantee from Interflow that their system would solve the infiltration problem under these conditions. Will Interflow guarantee this with no provisos?