Glossary
Advanced oxidation
Advanced oxidation is a step in the advanced water treatment process that uses powerful oxidants and ultraviolet light to destroy trace levels of organic or microbiological organisms in water that has not been rejected by reverse osmosis.
Disinfection
Disinfection is a the last step of the advanced water treatment process in which hypochlorite is added to purified recycled water to prevent biological growth in pipelines.
Environmental and Social Impact Assessment
An Environmental and Social Impact Assessment (ESIA) is a voluntary assessment conducted to identify, evaluate and develop management measures for environmental and social impacts associated with the construction and operation of a project. Two ESIAs were conducted as part of the Western Corridor Recycled Water Project. This process followed the Queensland Environmental Protection Agency guidelines for preparing an Environmental Impact Statement (EIS), including a minimum public consultation period of four weeks, despite there being no statutory need to conduct an EIS.
Horizontal directional drilling
Horizontal direction drilling is a trenchless method of installing underground pipes in a shallow arc along a prescribed bore path by using a surface launched drilling rig. Horizontal directional drilling is used when trenching or excavating is not practical, and minimises any environmental impacts on land and aquatic environments. Horizontal directional drilling is being used for several river crossings along the Eastern Pipeline as a cost effective strategy and to avoid surface impacts on a number of wetland and environmental areas.
Indirect potable reuse
The blending of advanced treated recycled or reclaimed water into a natural water source (groundwater basin or reservoir) that could be used for drinking (potable) water after further treatment. In South East Queensland, water from the Western Corridor Recycled Water Scheme will be used for indirect potable reuse if combined dam levels drop below 40 per cent. After passing through the advanced water treatment plants the water will be added to Wivenhoe dam for dilution and retention, before being treated at the Mt Crosby Water Treatment Plant.
| Microfiltration Microfiltration, the first treatment process at the advanced water treatment plant, involves passing wastewater through very fine hollow fibre membranes. With pores the size of 0.1 to 0.2 micrometres (human hair ranges in size from 20 to 200 micrometres in diameter), these membranes remove particulate matter, protozoa and some viruses. After passing through the membrane, the filtered water contains only dissolved salt and organic molecules. |
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Pilot plant
A pilot plant is a small-scale plant that simulates the operation of a full-scale facility. Pilot plants are used to validate the advanced water treatment process, select the best membranes for the available raw water and identify any adjustments that need to be made in the full-scale plant to ensure optimal operation.
Primary wastewater treatment
Primary treatment is the first stage of processing at wastewater treatment plants. It removes the materials that can be easily separated from the raw wastewater. The typical materials that are removed during primary treatment include fats, oils, and greases, sand, rocks, human waste and floating materials.
Project alliance
From the Department of Treasury and Finance 2006, Project Alliancing Practitioners’ Guide,
A project alliance is a commercial legal framework between a department, agency or government-backed organisation as ‘owner’-participant and one or more private sector parties as the ‘service provider’ or non-owner participants for delivering one or more capital works projects, characterised by:
- the collective sharing of nearly all project risks no fault, no blame and no dispute between the alliance participants
- payment of non-owner participants for their services using a three-limb compensation model comprising of:
- reimbursement of non-owner participants’ direct project costs
- a fee to cover corporate overheads and normal profit
- a share regime where the rewards of outstanding performance and the pain of poor performance are shared equitably among all alliance participants
- unanimous principle-based decision making on all key project issues
- integrated project team selected on the basis of best person for each position.
Pumping station
Pumping stations are facilities that house equipment used to pump and lift fluid from one place to another.
Purified water
Purified water is water that has been treated to the highest standard drinking quality through microfiltrations, reverse osmosis and advanced oxidation.
Raw water
Raw water is water received from wastewater treatment plants that has not yet undergone the advanced water treatment process. This is also referred to as secondary treated water or feed water.
Reclaimed water
Water that is used more than one time before it passes back into the natural water cycle. Wastewater that has been treated to a level that allows for its reuse for a beneficial purpose. Reclaimed water is sometimes another name for recycled water.
| Reverse osmosis Reverse osmosis is a step in the advanced water treatment process following microfiltration that involves forcing filtered water through a specially engineered membrane at high pressure to remove impurities such as dissolved salts, viruses, pesticides and most organic compounds. Reverse osmosis produces water that is of a higher level of purity than our current drinking water, and is the same process used to desalinate seawater. |
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Secondary treated water
Removal of biodegradable organic matter and suspended solids from wastewater. Activated sludge and trickling filters are two of the most common methods used. Disinfection is also typically included in the definition of conventional secondary treatment. These processes do not remove nutrients (nitrogen and phosphorus).
Sewage treatment plant
A facility designed to receive the wastewater from domestic sources and to remove materials that damage water quality and threaten public health and safety when discharged into receiving streams or bodies of water.
Stabilisation
A part of the advanced water treatment process which follows advanced oxidation that prevents corrosion of piping and pumping equipment, involving the addition of lime and Carbon dioxide to water to create hardness and alkalinity.
Tertiary treated water
Treatment beyond secondary treatment which typically involves the removal of residual organic and inorganic substances by granular media, surface or membrane filtration.
Wastewater treatment plant
A facility where wastewater from a community is processed to improve its chemical and biological composition to a point where it can be safely released to the environment. As part of the Western Corridor Recycled Water Project, treated water from numerous wastewater treatment plants in South East Queensland will be transferred to advanced water treatment plants for additional treatment and the production of purified recycled water.