GreyFlow™ GTS | Treated greywater for subsurface irrigation
GreyFlow™ GTS3 | Clear 3 Greywater Treatment System
GreyFlow™ Clear 3 treats greywater for approved subsurface irrigation and land application in domestic, shared-use and commercial installations.
It is the entry treatment level within the GreyFlow™ Clear range and can be combined with distributed GreyFlow™ diversion devices, central treatment, storage and an engineered land-application system.
Australian classLevel 3
AS 1546.4:2016 reference
NZ treatment referenceSecondary +
Secondary-quality BOD/TSS with strong disinfection target
TSS / BOD<30 / <20
Manufacturer-stated mg/L targets
E. coli<10
Manufacturer-stated cfu/100 mL target
New Zealand treatment reference: the stated Clear 3 BOD and TSS targets align most closely with secondary-treatment quality, while its stated E. coli target represents a substantially stronger microbiological / disinfection performance than ordinary secondary treatment alone.
Treatment performance
Designed around subsurface land application
Total Suspended Solids
AWWS stated target: less than 30 mg/L.
Biochemical Oxygen Demand
AWWS stated target: less than 20 mg/L.
E. coli
AWWS stated target: less than 10 cfu/100 mL.
Manufacturer-stated application
Subsurface drip irrigation.
Flexible collection design
Use distributed diversion devices with central treatment
GreyFlow™ GDD units can be installed at individual dwellings, buildings or wastewater-source groups and connected to a shared Clear 3 treatment installation where this suits the site.
- Allow individual branches to be isolated.
- Direct suitable flows locally where approved.
- Send selected greywater to central treatment.
- Stage site connections and treatment loading.
- Maintain operational flexibility as site use changes.
This distributed architecture can be particularly useful where buildings are spread across a site or where greywater production and land-application demand vary between different areas.
Wastewater sources
Kitchen water can be treated when properly pre-managed
Bathroom
Showers, baths and handbasins.
Laundry
Washing machines and laundry tubs may be included.
Kitchen wastewater
Kitchen sink and dishwasher flows can be included where they are specifically designed into the GTS. A dedicated grease trap or comparable grease-management stage is recommended on the kitchen branch.
Blackwater
Not part of the standard GreyFlow™ greywater treatment configuration.
Kitchen wastewater is not suitable for simple direct greywater reuse. Where used with the GTS it must pass through the treatment system, with appropriate grease and solids management ahead of treatment.
New Zealand compliance reference
Secondary-quality treatment with a strong disinfection target
Australian reference
AS 1546.4:2016 Level 3.
Closest practical NZ treatment reference
Secondary-quality BOD and TSS performance with a strong treated-water disinfection / pathogen-reduction target.
Typical NZ end use
Subsurface drip or another accepted land-application method, subject to site and council requirements.
AS/NZS 1547
May form part of the design basis for applicable on-site domestic wastewater and land-application systems.
Larger / commercial installations
Require a project-specific engineering, hydraulic and regulatory assessment.
The treatment plant and the land are one wastewater-management system. Meeting a treatment target does not by itself establish the allowable hydraulic loading, field area or permitted discharge.
Land-application design
Treatment quality does not create land-disposal capacity
- Confirm soil type and design loading rate.
- Confirm groundwater and seasonal groundwater conditions.
- Provide required setbacks.
- Check slope, flooding and surface-water risks.
- Allow sufficient irrigation area for the design flow.
- Account for wet weather and periods of low plant demand.
- Provide overflow and failure management.
- Maintain service access to treatment and irrigation equipment.
Smart controls and zoned irrigation can improve distribution and operating flexibility, but they do not replace the need for adequate soil and land-application capacity.
WCTNZ® is the exclusive authorised New Zealand distributor of GreyFlow™ greywater systems. WCTNZ® provides local product guidance, system scoping, documentation support, installation-interface coordination and lifecycle support for New Zealand projects.
