Vanuatu Installation for Urban Water Supply

Construction of a 3000m³ Timbertank in Whitianga




A mechanical system within a tank which oxygenates wastewater in the treatment process.


Backwash tank

A tank containing water from backwashing process.

Balance tank

A tank for the storage of surplus water during start-up or close-down of a water treatment plant.

Biodigester tank

A methane generating tank and gasometer.

Biogas (methane)

A colourless flammable gas consisting of hydrocarbon (CH4) resulting from decay due to the action of anaerobic bacteria.



The injection of chemicals into irrigation water and its application to the crop or field.


A large tank or basin in which water is held during the water treatment process so that heavier suspended solids fall to the bottom.


Embedded energy

Energy consumption in the production process, from raw material source to finished product.



Wastewater other than sewage, ie sink and bathwater drainage or washing machine discharge.


Header tank

A small elevated water tank which ensures constant water pressure is maintained.



Channels consisting of overflow weir plates and conveying troughs installed in water treatment plant tanks.


Trade name for an instrument which correctly shows the water level in a water tank.


Municipal water

Water which has been processed at a central plant to make it potable and is then distributed via water mains to homes and businesses.


Pinus Radiata

Monterey Pine, native to California, extensively plantation grown in New Zealand. Radiata describes the spoke-like growth pattern of the branches.

Potable water

Water suitable for drinking, usually filtered and treated to remove contamination, and stored or transported under strict guidelines to preserve the uncontaminated state.

Process water

Water used in manufacturing or treatment or in the product manufactured. Water is often specifically treated to obtain the water quality required for a process.


Rain water harvesting

The collection of run-off from roofs into tanks for water supply.

Raw water

Water in its natural state, prior to any treatment.

Renewable resource

A resource which is capable of being replenished through natural processes or its own reproduction within a time span of a few decades.


Any natural or artificial holding area used to store water.


Sand filters

The oldest and most basic water filtration process which generally uses two grades of sand (coarse and fine) for turbidity removal.

Septic tank

A tank into which the solid matter of sewage flows and is held for decomposition by bacteria.

Storage tank

A tank used to accumulate water from a water treatment plant so sufficient quantity is available for intermittent periods of higher flow rate water use.

Stormwater detention

Tanks which provide temporary stormwater storage to avoid overload of stormwater drains during heavy rain.

Structural timber roof

The roof of a Timbertank tank or reservoir is engineered to maintain the barrel shape and support the roof sheathing.

Surge chamber

A chamber or tank connected to a pipe and located at or near a valve which may suddenly open or close. The chamber allows water to flow in or out of the pipe, minimising any sudden positive or negative pressure waves or surges in the pipe.

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