There are currently no water restrictions in place but we always ask residents to be conscious of water usage and it’s impact on the environment. Visit the Smarter Homes website for more information on how to save water around your home.
The Water Treatment Plant was opened in September 1983, and supplies a population of almost 20,000 mainly residential consumers. It is located about 10 km west of Masterton, on the north side of the Waingawa River, from which water is extracted for town supply.
Daily consumption varies from about 9 million litres per day during winter, to a high of 25 million in summer.
How is my water treated?
Water is extracted from the river by siphon to draw the flow into a concrete main. This feeds the Water Treatment Plant 5 kms downstream. The flow is gravity assisted as it goes, with air being taken out of the pipe at several points along the line, to help maintain a full pipe.
At the treatment plant, raw (river) water is stored in three holding ponds until required. In the event of flooding and dirty river water, the flow can be shut off and the plant can run on its stored capacity for 3-4 days.
From the ponds, water is let into a large concrete vessel or clarifier, where the chemical coagulants PAC (poly aluminium chloride) and polyelectrolite are added to form small floc particles, which attract the fine suspended silt and clays present in the water. These drop to the bottom of the clarifier as sludge.
Five sand filters are used to “polish” the water to a high degree of clarity and remove any residual floc particles. The filtered water is then piped to a covered clear water pond.
Chlorine, Fluoride & Lime
Metered dosing is carried out at the clear water pond, using chlorine (disinfectant to give protection from micro-organisms which may enter the distribution system), fluoride (prevention of dental cavities in children), and lime (to raise the pH of the water making corrosion of pipes less likely).
The last storage point before water enters the town mains is the Upper Plain Reservoir, supplemented by smaller reservoirs on Lansdowne hill. The supply is almost all gravity fed from our reservoirs, with only a limited amount needing to be pumped to the highest point.
Fluoride free water is available to the public at a dedicated tap installed outside the Manuka Reserve in Manuka Street, Masterton.
The Homebush Wastewater Treatment Plant
The Masterton District Council’s urban wastewater (sewage) treatment facility is located at Homebush to the east of Masterton. A reticulated sewerage system collects wastewater from Masterton’s approximately 20,000 residents and transports it 4 kms to Homebush for treatment and disposal. The reticulation system uses a predominantly gravity system that is augmented in low lying areas by two pump stations and a siphon.
The Treatment Ponds
The wastewater treatment ponds cover an area of approximately 28 hectares and are divided into two inflow or primary ponds and five linked maturation ponds. The plant is fully automated with the levels in the primary ponds and the maturation ponds controlled by computer. The ponds have sufficient capacity to hold 270,000 cubic meters of wastewater, have embankments heights from 2.5 to 3.2 meters and are lined with 1.5mm thick high density polyethylene (HDPE).
The Ruamahanga River Outfall Diffuser
The diffuser outfall to the Ruamahanga River was commissioned in June 2013 and allows treated wastewater to be discharged and mixed with river water to meet strict Resource Consent requirements. The outfall system comprises two automated pen-stocks located in Pond 6, the last of the maturation ponds. Wastewater enters the pen-stocks when either or both of the outfall gates are opened and flows 900 meters through a 1.2 meter diameter pipeline to the diffuser outfall. The diffuser outfall comprises four discharge pipes connected with, and at right angles to, the main pipeline. These pipes are buried in the river bed and have mesh screens over the end to prevent rocks and boulders entering the system.
When river conditions permit, treated wastewater is discharged through the diffuser outfall pipes and turbulence within the river mixes the wastewater with the river water to achieve the water quality requirements of the Resource Consents.
The Border Strip Irrigation System
When river conditions do not allow discharges through the diffuser, treated wastewater will be irrigated to the border strips. The border strips are a series of fields that will be irrigated with treated wastewater. They are 24 meters in width and vary in length from 150 meters to 300 meters and are separated by “borders” or “dykes” that are raised mounds of compacted earth. The borders act as small dams and contain the irrigation water within the area of each strip allowing control of application rates. The border strips will be irrigated on a 7 to 10 day cycle, depending on weather conditions and the time of the year. The grass growing on the border strips will be harvested and sold for animal food. Strict conditions apply to the production and testing of the baleage to ensure that it is safe for consumption by animals.
Makoura Stream Riparian Planting
The Makoura Stream meanders its way through the Homebush site and discharges into the Ruamahanga River just downstream of the diffuser outfall. Removal of exotic trees (willows, poplars, pines, etc) and planting of the riparian margins of the stream were undertaken as part of the upgrade of the treatment plant. In total some 16,000 native trees and shrubs were planted along the stream and the main irrigation channel that runs through the site. The trees and shrubs are irrigated with treated wastewater via sub-surface drippers. Irrigation ensures a greater survival rate for the young plants, it helps in the disposal of treated wastewater and recognises that treated wastewater is a resource that can be used in a beneficial manner.
Testing Treated Sewage
Monitoring of dissolved oxygen, suspended solids, pH, temperature and a range of other factors is undertaken on a daily basis. Laboratory analysis of samples is undertaken to determine the performance of the plant and the results are measured against Resource Consent criteria.
Flows, faults and equipment status are monitored 24 hours a day, 365 days a year and are relayed through a radio telemetry system to a central computer where they are received and logged. Alarms alert the plant operator if there are any issues needing attention.
Water & Wastewater Treatment Plant Supervisor – Kevin Godfrey
Water & Wastewater Treatment Technicians – Andrew Cutfield/Kevin Crosby
P: 06 377 4527
F: 06 378 7850
M: 0274 426 456