SA Water is trialling the use of artificially-generated smoke to identify cracked or broken sections of pipe, and incorrect or illegal stormwater connections within its sewer network.
All of these issues impact the reliability of wastewater services and can be harmful to the environment.
The method is commonly used by water utilities around Australia as a way of finding out where stormwater is entering the sewers, which can contribute to overflows or potentially overwhelm the receiving wastewater treatment plant, particularly during or after a heavy rain event.
SA Water’s Senior Manager of Capital Delivery, Peter Seltsikas, said the activity is being undertaken at Hahndorf in the Adelaide Hills which – based on ongoing monitoring data – experiences a higher than average number of sewage overflows and network surcharges.
“During heavy downpours, stormwater can find its way into the sewer mains, which has the potential to significantly raise the volume and flow of wastewater in the network and increase the risk of sewage overflows to the environment or onto a person’s property,” Mr Seltsikas said.
“While stormwater-related surcharges are not the only reason for overflows, they are something we can all avoid if both SA Water’s and our customer’s pipework is properly and correctly maintained.”
After putting smoke into the sewer network, it may come out of stormwater downpipes on the side of a building’s roof guttering, from the road surface or a broken inspection point lid.
“If this happens, it’s an indication of either a defect in our underground sewer pipes or an incorrectly-plumbed stormwater connection into the wastewater network,” Mr Seltsikas said.
“All the information we gather as part of these inspections will inform solutions, such as replacing or repairing sections of sewer main or working with property owners on remediation options.
“We appreciate that some people may not be aware they have an illegal stormwater connection on their property, but it’s important the issue is rectified, and we encourage them to contact a licensed plumber for assistance.”
The machines being used as part of the trial are similar to what’s used at concerts or for special effects and omit a grey-like smoke, which is harmless to people, plants, animals and the environment, is odourless, doesn’t stain and dissipates within a few minutes.
“The local community has been given advance notice of the work, and our contractor PPS has also advised the Country Fire Service, in case any smoke is observed,” Mr Seltsikas said.
“During the work, we may need to access easements along the roadside as well as driveways and front yards.
“There will be no disruption to our local customers’ wastewater service as a result of the inspection, and they can continue to use taps and other plumbing fixtures as per usual, as smoke won’t come out where there is a water seal, such as in a toilet.”