About our wastewater

What is sewage?

All the water within our region, once used is referred to as sewage.  Sewage is 99.97% water as the majority of it comes from showers, baths and washing machines.  The rest is dissolved and suspended matter.

Sewage comes from domestic, commercial and industrial sources.  The collection, treatment, disposal and reuse of sewage throughout our region forms an integral part of the water cycle.

Where does our sewage go?

All of our used water that is flushed down the toilet or let go down the drain doesn’t just disappear, it travels through our sewage system to a sewage treatment plant.  A number of sewage treatment plants are located throughout our region, operating to treat all of the sewage that we produce.

It's important to remember that whatever goes down drain must be taken out again.  It's pretty amazing to see what gets poured down the drain or flushed down the toilet upon a closer look - medicines, food colouring and flavours, coffee grounds, personal care products, detergents, dyes, paints, plastics and even toys.

Our sewage treatment plants also have to deal with the chemicals and waste produced by agriculture and heavy industries.  Some of these materials can easily break down, but others don't degrade that easily.  Simple things like baby wipes are pretty good at blocking up sewers - many people are unaware that these types of things shouldn't be going down the toilet.

Everything we pour down the sink or flush down the toilet passes through the sewage system and must be dealt with by pumps and treatment equipment.  Disposing of household wastes in the correct manner can help overcome problems with the collection and treatment of sewage and at the same time protect the environment.

How is sewage treated?

At the sewage treatment plant the sewage goes through a series of processes that remove the pollutant materials from the water such as solids, oil and greases, detergents, nutrients, heavy metals and bacteria.

Once the treatment process is over there are two end products – treated sewage and biosolids.  The treated sewage is returned back into the environment.  At some of our facilities, the sewage can be treated to a level where it can be reused as irrigation on cane farms and golf courses.

The biosolids produced from sewage can also be reused as a low grade fertiliser or soil conditioner.

For more information about our sewage treatment plants, visit the H2O Infrastructure page.

Inflow and infiltration into the sewage system

Stormwater can enter the sewerage system through sources on both public roads and private properties via cracked pipes, leaky manholes, low overflow relief gullies or improperly and sometimes illegally connected stormwater drains and downpipes.

The sewerage system is not designed to carry stormwater and excess flow into the system can cause drains to back up and even overflow sewage, compromising public health and the environment!

House drains are the responsibility of each property owner and they need to be maintained to ensure that stormwater and groundwater doesn’t enter the sewerage system.  The house drain from each property connects to a sewer pipe or sewer manhole, the sewer and sewer manholes are council's responsibility.

For more information, download the Inflow and Infiltration brochure.