On-site sewerage facilities and greywater

A large number of properties across the Fraser Coast are not connected to a reticulated sewerage system. The treatment and disposal of all wastewater generated on these properties must be undertaken by an on-site sewerage facility.

An on-site sewerage facility consists of two basic parts; a treatment facility to treat the wastewater and a land application area to dispose of the wastewater.

On-site sewerage facilities are basically a mini sewerage treatment plant in your backyard and home owners have a responsibility to ensure that they are working properly to protect both the health of your family and the community and also the health of the environment.

To find out more about OSSF, view the fact sheet or video by clicking on the links below:

Fact Sheet     OSSF Overview Video

  • An on-site sewerage facility is any system that stores, treats and disposes of household wastewater within the boundary of the property. An OSSF consists of two basic parts; a treatment facility to store and treat the wastewater and a land application area to dispose of the wastewater.

    On-site sewerage facilities are basically a mini sewerage treatment plant in your backyard and home owners have a responsibility to ensure that they are maintained and functioning properly to:

    • protect both the health of your family
    • protect the community
    • protect the health of the environment.


    All OSSF's require a plumbing permit (approval) from council before installation or alteration. A licensed, registered site and soil evaluator will attend the property and conduct an investigation and recommend the type and level of treatment required and provide an adequate design.

    A licensed drainage contractor can install the facility after receiving a copy of the permit and approved plan. It is the responsibility of the contractor to, install the facility correctly, ensure completion of inspections and certifications and provide a final inspection certificate to the owner.

    To find out more about OSSF, view the fact sheet or video by clicking on the links below:

    Fact Sheet     OSSF Overview Video

  • Yes, there are a number of different types of systems;

    Aerated wastewater treatment systems treat the captured effluent so it can be reused around the yard in a designated area. The wastewater will go through either three or four stage process, after the wastewater is aerated and churned up it needs to settle to let the solids settle out. The solids settle out and there is clarification of the wastewater resulting in nice clear effluent. From clarification, the effluent goes across to the chlorination chamber where the effluent is chlorinated to kill any pathogenic organisms that could harm the family. After chlorination, the effluent is pumped to the land application area.

    To find out more about aerated wastewater treatment systems, view the fact sheet or video by clicking on the links below:

    Fact Sheet     Aerated Wastewater Treatment Systems Video

    Aerobic Sand Filtration systems capture all of the household wastewater into a Primary Tank where the initial anaerobic bacterial decomposition occurs. The resulting primary-treated effluent from the Primary Tank then undergoes secondary treatment by passing into and through the Aerobic Sand Filter. This Secondary Treatment is achieved by the action of microbiological culture within the Sand Filter. This Sand Filter is built ‘in-ground’ and sized to suit the volume of effluent to be treated. This stage completes the treatment process.

    To find out more about aerobic sand filtration systems, view the fact sheet or video by clicking on the links below:

    Fact Sheet

    Septic systems break down the wastewater consisting of blackwater (toilet waste) and or a combination of grey water (all other fixtures) using micro-organisms. These micro-organisms break down the wastewater into a layer that floats called a scum layer and a layer that sinks to the bottom of the tank called a sludge layer. The liquid that is left in the middle is called supernatant, this liquid is transferred to the land application area.

    To find out more about septic systems, view the fact sheet or video by clicking on the links below:

    Fact Sheet     Septic Systems Video

    Greywater is any wastewater generated from your laundry (and appliances), bathroom (baths, showers, basins), it does not include toilet or kitchen sink wastewater which is classed as blackwater. A greywater diversion device can divert greywater to an irrigation system. They can include a filter that screens out hair, lint and other solids. A greywater treatment plant collects, stores, treats and disinfects greywater to specific standards, the effluent is pumped to the land application area.

    To find out more about greywater, view the fact sheet or video by clicking on the links below:

    Fact Sheet     Greywater Video

    Sullage system disposes of the domestic waste from kitchens (via a grease trap), baths, showers, basins and laundries. A grease trap is a small tank, usually installed close to the kitchen, to take greywater from the kitchen sink and prevent grease entering the system. Sullage tank units consist of the tank with a submersible pump partially elevated toward the bottom which pumps out the cleaner water, while retaining the silt and dirt particles (called sludge). The water which exits the greywater sullage holding tank will either travel to an irrigation system or to a greywater purple sullage hose where it is watered onto the lawn/paddock. Sullage systems are no longer approved.

    To find out more about sullage systems, view the fact sheet or video by clicking on the links below:

    Fact Sheet     Grease Trap Video

    Composting or dry vault system treats human waste by a biological process called composting. This process leads to the decomposition of organic matter and turns human waste into compost-like material. Composting is carried out by microorganisms under controlled aerobic conditions. As waterless composting toilets do not treat greywater (wastewater from other sources such as showers, sinks and washing machines) an alternative system is needed.

  • A land application area is the area where the treated wastewater must be disposed within your property. The design, installation and maintenance of your land application area is important. Each step protects the environment and the health of your family and neighbours. There are several disposal methods:

    Irrigation system:

    • Surface irrigation systems distribute chlorinated effluent over grassed or gardened land application area
    • Sub-surface irrigation distribute chlorinated effluent to the land application area via a network of small bore piping through drippers spaced regularly to spread the effluent in shallow trenches below ground
    • Covered surface irrigation  release effluent via a network of small bore piping through drippers on top of natural ground covered by mulch or woodchip

     

    Evapotranspiration and or absorption trench/bed/mound:

    • Effluent is distributed through the bed or trench by a system of slotted pipes or plastic arches. Capillary action draws effluent up from a lower gravel bed through sand to supply the root zone of vegetation (usually grass) on top of the bed or releases through the gravel and sand to the underlying soil
    • Elevated sand mound is a land application area that is raised above the natural ground with a specific sand fill material. Within the sand fill is a gravel-filled bed, effluent is pumped in controlled doses into the bed insure uniform distribution throughout
       

    The type of land application area will depend on the level of treatment the wastewater has received prior to disposal.

  • On-site sewage facilities need regular maintenance to ensure they operate in a safe and effective manner. Poorly maintained and malfunctioning systems can impact public health, the environment and property value. It is very important to understand that maintenance of an on-site sewage facility. Waste water treatment plants and sand filters are mandatory under the Plumbing and Drainage Act 2018 and is essential for the satisfactory performance of the facility. The type of maintenance varies depending on whether the system is a treatment plant, sand filter or septic system.

    Complaints can arise from waste water trenches overflowing, unpleasant smells, waste water sprinklers being too close to neighbours and waste water running into neighbouring properties. All these issues present a serious health risk for the community and need attending to immediately. Care should be taken to ensure that waste water remain in the land application area. The failure of an on-site sewerage facility (OSF) is often caused by one or a combination of the following:

    • overflowing LAA
    • odours from the OSF
    • blockages i.e. tree roots
    • essential bacteria killed by household cleaning chemicals
    • damaged structural components
    • failed mechanical components, including pumps and blowers
    • leaching into groundwater
    • failure to meet effluent quality standards
    • excessive water use
    • lack of system maintenance
    • incorrect OSSF design or system selection
  • If a septic tank accumulates too much sludge and scum, the effective volume of the tank is reduced, which reduces the amount of separation that can take place. This means not all the solids, grease and oils will separate and pass out of the septic tank and into the drainage beds/trenches. This can clog the soil surrounding the drainage beds/trenches.

    Important maintenance includes:

    • avoiding anti-bacterial products and using only septic safe products
    • being alert to any failure of the electrical components of the system
    • acting on any change in odour coming from the plant
    • desludging the septic tank unit every three to five (3-5) years by a licensed liquid waste contractor
    • the land application area must have the grass mowed and plants maintained
    • protect the land application area from vehicles
    • take reasonable steps to keep all plumbing and drainage on the property in good condition
    • ensure the system does not create a nuisance or pose a health risk to the surrounding area.


    For more information, please see Council’s Septic System Fact Sheet

  • It's called an aerated wastewater treatment system because it relies on large volumes of air being pumped into the system and that air allows vast numbers of bacteria to grow and break down the solids within the wastewater. An on-site sewage treatment plant uses mechanical, biological and filtration methods to treat waste.

    Aerobic Sand Filtration capture all of the household wastewater in a primary tank, primary-treated effluent then undergoes secondary treatment by passing into and through the Aerobic Sand Filter. This Sand Filter is built ‘in-ground’ comprising layers of sand and graveland sized to suit the volume of effluent to be treated. Sand is a highly effective, naturally absorptive material that can treat effluent to a very high standard.

    Important maintenance includes:

    • avoiding anti-bacterial products and using only septic safe products
    • being alert to any failure of the electrical components of the system
    • acting on any change in odour coming from the plant
    • desludging the primary tank unit every three to five (3-5) years by a licensed liquid waste contractor
    • the land application area must have the grass mowed and plants maintained
    • protect the land application area from vehicles
    • take reasonable steps to keep all plumbing and drainage on the property in good condition
    • ensure the system does not create a nuisance or pose a health risk to the surrounding area.


    Servicing may include:

    • measure sludge and scum levels
    • ensure adequate chlorine supplies
    • ensure pumps and blowers are operational
    • clean filters
    • test chemical levels
    • check for evidence of bacteria die-off
    • check mechanical components
    • ensure plant is in operational condition
    • submitting a service report to council
  •  It is recommended that composting toilets are serviced annually by an approved contractor. Annual servicing should include a check of the operation of the fan and the amount and spread of the compost within the composting chamber(s). Regular maintenance is the responsibility of the owner and requires a commitment to composting.

    Good maintenance procedures include:

    • recording the commissioning date of each chamber of multi chamber systems
    • always close the toilet lid when the toilet is not in use to control fly breeding and ensure proper aeration of the pile
    • ensure the material is spread evenly over the compost heap
    • always clean the pedestal by hand with minimal use of water and no disinfectants
    • consult the service agent if odour and vermin become excessive
    • regularly check moisture and temperature conditions to maintain optimum conditions for composting
    • add organic and bulking material when required
  • Council is required to maintain a register of all on-site sewage facility treatment plants and requires service agents to submit maintenance reports regularly. If Council does not receive a service report when your service is due, an enforcement letter will be sent requesting a copy.

  • Greywater from the bath, shower, hand basin and laundry can be diverted for reuse on lawns and gardens. Kitchen greywater is not suitable for reuse as grease and oil can clog irrigation systems and build up on soil surfaces. Untreated greywater should not be stored.

    A greywater diversion device can divert greywater to an irrigation system. They can include a filter that screens out hair, lint and other solids. A greywater treatment plant collects, stores, treats and disinfects greywater to specific standards. Greywater can be re-used as long as the installation complies with the requirements of the Queensland Plumbing and Wastewater Code 2019. This code sets out the requirements to protect the health of the community and environment.

    A greywater use facility must be designed, approved, constructed, installed and maintained in such a manner as to protect public health by ensuring that risks associated with the use and / or disposal of greywater to the land application area are minimised and protect the environment by ensuring surface and ground water is not polluted and soil productivity is contained or enhanced.

    Residents in sewered areas may redirect greywater by means of:

    • manual bucketing;
    • connecting a flexible hose to a washing machine outlet;
    • greywater diversion devices and grey water treatment plants (with Council approval) by licensed plumbers, connected to an irrigation hose; and
    • surface or sub-surface system (with Council approval)

     

    Care should be taken if reusing greywater because of:

    • potential health risks to humans; and
    • potential for environmental damage to soils, ground water, and waterways caused by increased nutrient and chemical levels.

     

    Please note that the requirements regarding greywater disposal is regulated under the Plumbing and Drainage Act 2018 and require a plumbing permit (approval) from council before installation or alteration to ensure that greywater run-off does not cause a danger or health risk.

  • You will need a Council permit before installing either:

    • a greywater diversion device, which diverts greywater from the bath, shower, hand basin and/or laundry to an irrigation hose, or;
    • a greywater treatment system which collects and treats it to a high standard for reuse as garden irrigation.
  • No, untreated greywater should not be stored.

Contact us

For further information, please contact Council's Customer Service Centre on 1300 79 49 29 or email enquiry@frasercoast.qld.gov.au