Treated water for the supply of Waiouru township is purchased from the NZ Army Training Group. The intake and Water Treatment Plant are owned and operated by the Army. Council purchases the treated water from the Army in bulk and distributes it to the township, including the Army Museum. Council is only responsible for the operation and maintenance of the reticulation system within the 'civilian' area of the Waiouru township.
The following information refers to the supply and treatment of water by the NZ Army Training Group.
Where does my water come from?
Water for the supply of Waiouru comes from the Waiouru Stream Dam. Water is screened as it enters the intake structure (shown in the figure below) to remove larger debris such as sticks, leaves, fish and rubbish.
Is my water treated?
Yes, water is treated at the Waiouru Water Treatment Plant, located within the Waiouru Army Base facility.
Water treatment at the Waiouru Water Treatment Plant consists of the following:
- Powdered Activated Carbon (PAC)
Dissolved organic material in the water can cause taste and odour problems. To remove organic compounds Powdered Activated Carbon (PAC) is added to the water supply. Organic particles attach themselves to the surface of the carbon which is then removed from the water supply by finer filtration.
- Finer Filtration
Water is passed through layers of sand and gravel to further remove impurities. Small water molecules pass through the holes between sand and gravel pieces and clean water is collected in a drain at the bottom. Unwanted solids get stuck in the holes, and are thus retained in the sand and gravel medium. This medium is washed from time to time to remove the unwanted solids.
The filtration system, consisting of three sand filtration tanks, is shown below.
- Chlorination & pH Correction
The water is dosed with chlorine to kill off contaminants (bugs) in the reservoirs and pipes. pH correction is used when required to ensure effective disinfection with chlorine.
Where is my water stored?
Online monitoring through Supervisory Control and Data Acquisition (SCADA) provides information about the water treatment. This system checks that water parameters stay within set values for 24 hours every day and will alert the Plant Operator if it changes.