Water and Sewer Main Cleaning

Our ongoing program of cleaning water and sewer mains across our region is an integral part of our network operations to ensure we maintain and deliver services to customers.

> Water mains

Why do water mains need cleaning?

The ongoing maintenance of our water network is important to ensure the continued delivery of safe drinking water. Cleaning water mains ensures we continue to meet the Australian Drinking Water Guidelines. It also assists in protecting the integrity of our water main network and helps prevent issues.

Interruption to water supply

If customers are affected by planned water main cleaning they will receive works notification seven days prior to any interruption to water supply.

Water main cleaning techniques

We utilise a variety of the latest mains cleaning techniques to maintain the quality of our drinking water.

Water mains are flushed to help remove the natural build up of sediments inside pipes. Flushing the main involves opening hydrants to flush the water and any sediment through the mains at high speed.

Air scouring
Air scouring involves forcing a mixture of compressed air and water into the mains. This process also removes any sediment and helps maintains disinfection levels within the water supply network.

Ice pigging
Ice Pigging involves pushing a thick ice slurry, a mixture of semi-solid ice and water, through the main. The slurry is then removed from a hydrant and collected in a tanker. This method uses minimal water and is environmentally friendly. It reduces risks to our network and there is no need for excavation.

Swabbing involves forcing a large ‘sponge’ through a water main to remove sediment. The sponge is propelled by water pressure. The swab is removed along with any sediment and debris it collects.


Above: ice pigging used for water main cleaning in Echuca

> Sewer mains

Why do sewer mains need cleaning?

The ongoing cleaning of our sewer network is important to help prevent blockages and improve the efficiency and reliability of our service. Sewer overflows are costly to clean up if they occur inside your home, and pose a significant risk to the environment and waterways. We have increased preventative maintenance works to reduce the number of blockages in our network.

Interruption to customers
Customers may be affected by planned sewer main cleaning if they have a sewer manhole on their property. Customers will receive notification seven days prior to our contractors accessing their property.

Sewer main cleaning techniques
We utilise a variety of techniques for cleaning sewer mains tailored to the condition of the main. The condition of the sewer mains is assessed using CCTV and acoustic sensing technology.

The jetting of sewer mains is the most common form of cleaning. Jetting takes place in a section of sewer main between two manholes. It involves pushing a high-pressure hose with a cleaning nozzle through the main against the flow and then pulling it back through. Jetting is often used prior to inspection or renewals.

Chemical tree root treatment
Tree roots cause more than 70 per cent of sewer main blockages in our region. Roots searching for nutrients intrude into pipes and catch fats, oils and foreign materials which can reduce the flow and cause blockages.

Chemical tree root treatment is a foam herbicide that eliminate roots and prevents further structural damage of the main. Only roots within main pipe and a very short distance outside are affected. Trees and shrubs immediately above ground are not harmed.


Above: jetting used for sewer main cleaning in Bendigo

> Current Planned Works and Interruptions

During mains cleaning works some disruption to service and traffic interruptions may occur.

We try and keep this to a minimum and where possible provide advance notice by direct mail to affected customers and sometimes by public notices in local newspapers.

The latest information on planned works in our region is available on our Planned Works and Interruptions page and on the map below.



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