Fog testing of sewer network in Maclean and South Grafton

Inflow and infiltration testing of the Clarence Valley sewer system will take place in parts of Maclean and South Grafton during November and December.

Council’s Manager of Water Cycle, Greg Mashiah, explained that the testing is carried out by pumping an innocuous smoke-like fog into the sewer lines.

“The fog should come out of the main vent outlet on property roofs.”

“If it comes out of the gutters, storm water drains or emerges from the ground this indicates there may be an issue that needs to be looked at.”

“This testing allows us to quickly, easily and safely identify where there are either cracked or damaged pipes, incorrectly installed sewer relief gullies or downpipes that allow storm water to enter the sewer systems.”

“The sewage treatment plant runs most efficiently when there are no major spikes in the amount of water entering the system.”

Council’s water cycle team is able to analyse data after heavy rain events to identify any spikes in the volume of water entering the system. By isolating the pump station where the spike occurs they can focus on any potential problems and make repairs as required.

“Anything we can do to make the system more efficient results in savings for the community.  Properties with infiltration or inflow issues will be advised so they can correct the problem,” Mr Mashiah added.

The testing will commence from 16 November with work taking about 4 weeks to complete. Residents will be informed by letter drops if their home is within the testing area.

Release ends
4 November 2020