Overflow Relief Gully (ORG)
What is an Overflow Relief Gully (ORG)?
The Overflow Relief Gully (ORG), also sometimes called a gully trap, is a key feature of the house drain. It’s a grated outlet located outside your home or building, near an external wall, usually close to your kitchen, laundry or bathroom.
The purpose of an ORG is to prevent smells and sewage overflows occurring inside the home or building.
For an ORG to work correctly, it must be installed to plumbing regulations and be kept in good condition.
A working ORG:
- has a loose-fitting grate that can easily pop off
- is at least 150mm below the lowest drain in the house or building
- is at least 75mm above the finished surface level of the outdoor ground so that water does not pool/pond and run into the ORG
- is clear of obstructions like pot plants, landscaping or leaves and other items
- allows pool backwash to the ORG only in line with plumbing regulations
- has no down pipes or stormwater directed to the ORG
How does the ORG prevent sewage overflow inside a property?
When a blockage occurs in the wastewater network or in your house drain, the ORG grated cap should pop off to allow release of sewage outside the home or building.
If the ORG is not working correctly – for example, it might not be installed too high or too low, or have downpipes directed into it so it fills with water during heavy rain, or the grate might be sealed down and unable to pop off – sewage overflow is forced back into the drain system and can overflow through floor grates, toilets or sinks.
Who is responsible for maintaining my ORG?
Council is responsible for the wastewater network outside residential property boundaries. Property owners are responsible for household drainage within the property boundary, this includes the property’s ORGs (your property may have one or multiple ORGs). All inspection covers (manholes) are the responsibility of Council, including those located on private property.
Wastewater network
Council’s wastewater network, also called a sewerage system, is designed to transport sewage and wastewater from homes or businesses to the wastewater treatment plants through house drains, sewers and pumping stations. The wastewater network is not designed to carry lots of runoff from rainfall.
In times of heavy rainfall, the wastewater network can become affected by the inflow of stormwater which, in turn, can cause:
- the capacity of the network to become overloaded
- sewage overflows to occur (from manholes or plumbing fixtures at people’s houses, and at businesses)
What is inflow and/or infiltration?
Inflow and/or infiltration is any external source of water, stormwater or groundwater that enters the wastewater network. Most inflow is caused by:
- Illegal rainwater connections into the wastewater network, for example from downpipes diverted into the ORG
- Landscaping that diverts stormwater into manholes or overflow relief gullies (ORGs)
Inflow through the ORG can be unintentional when stormwater cannot get away due to landscaping or other obstructions blocking the flow-path of the stormwater. The stormwater builds up around the ORG and then, when high enough, drains into the ORG and then the wastewater network.
Residents need to be aware that any discharge of stormwater into the wastewater network, whether it be through the ORG or connection of storm water downpipes or drainage pipes, is illegal and if left unattended can result in a Council fine.
Why is water flowing into the sewerage system a problem?
Inflow and/or infiltration increases the volume of water in the wastewater network which can result in the network being overloaded. This causes the network to fill and overflow, potentially creating risks to human health and environmental harm. The additional pressure of stormwater inflow on our wastewater network can increase the cost to Council to transport and treat the wastewater. These costs can affect ratepayers. High stormwater related inflow increases the likelihood of pipe blockages and wastewater overflow during heavy wet weather events
How can I check my ORG?
Residents may not be aware that they have an illegal connection, but there are a few simple steps that can help identify if rainwater, ground water or stormwater is entering the wastewater network:
- Check that all downpipes discharge to the ground or to the street. This can be done by discharging water into your downpipe and observing where the water flows out. If no point of discharge can be found, there might be an illegal connection.
- Inspecting the area around the ORG to ensure that stormwater can flow away. Verify this during a rain event. If water dams up around the ORG, adjust the landscaping or remove the obstacle.
Please contact a licensed plumber if you cannot find your ORG, if you have downpipes directed into the ORG, or if you think you might have an illegal connection.
What is Council doing to address ground water or stormwater entering the wastewater network?
Council is committed to reducing illegal and inadvertent inflows into the wastewater system. Council undertakes annual programs that inspect and reline the wastewater network to minimise infiltration in the network. While this ongoing program assists Council in addressing ground and stormwater inflows into our wastewater network, Council also relies on residents to do the right thing.
Council is currently rolling out a smart wastewater monitoring trial, along with a property connection inspection program. This is to identify areas and properties contributing to inflow and/or infiltration and alert residents to repair and rectify illegal connections when found.
In some properties the ORG is susceptible to being below water during a rain or flooding event. As we detect these gullies Council staff will fit an ORC (Overflow Relief Cap) inside the gully. This ORC will prevent water from entering the sewerage network but will also allow sewage to flow out of the gully if it is ever required.
What to do if you have a blockage
Slow-draining sinks, toilets or showers, or a sewage overflow that occurs in dry weather could be a sign of a blockage in your pipes, or ours.
Townsville City Council recommends that in the event of problems with your house drain you call Council's 24-hour service on 13 48 10. Our staff will then assess the problem and either send a team to investigate and rectify the problem or recommend that you call a private plumber.
If Townsville City Council staff attend your property and find the blockage to be located in your house drain then you can request that we clear the blockage, for the standard blockage clearing fee plus the costs of any excavation or removal of structures or paving that may be required to access the drain. Alternatively you can call a private plumber.
If your plumber finds that the blockage or defect is in Townsville City Council's sewerage network, they must get permission prior to undertaking any works in our system. We will reimburse property owners for authorised work conducted on our sewerage network, including property services up to the value of the standard sewerage blockage fee.
Please note: Council does not clear house drain blockages on commercial properties.
Download and complete this form to claim reimbursement:
- Blockage Reimbursement Form (PDF, 142.9 KB)
What to do if your home experiences a sewage overflow
If your property, home or building has been impacted by a sewage overflow, as result of a problem with our sewerage network, we will complete an initial clean-up, which involves removing any solid material and rinsing and disinfecting the affected area to kill off bacteria and remove smell associated with sewage. Townsville City Council does not clean the interior of the home or building and the contents contained within.
If you believe your property has been damaged as a result of the sewage overflow you will need to lodge a claim with your insurer, who will organise the restoration of your property and will liaise with us about your insurance claim.
If your property is not insured, find out how you can make a claim on our Complaints page.
