For Residential And Low Impact Areas

Gross Pollutant Trap (GPT)

Independently Tested and Approved:

  • Removes 100% gross pollutants, 86% nutrients and coarse sediments
  • Rapid manufacture and delivery
  • Easy to transport
  • No pit inserts or secondary units required
  • Quick and simple in-line installation, fitted into drainage system
  • Compliant with EPA legislation
  • Easy access for maintenance
  • Single system replaces treatment train
  • Suitable for residential developments

Contact your Enviro Australis distributor in your state now.


How it works

The Enviro G Series act as a Gross Pollutant Trap (GPT) and is an inline unit that incorporates multiple processes and chambers within one prefabricated enclosure. Our units are available to suit pipe sizes ranging from 225 to 1050 mm.

As stormwater enters the unit, sediments are separated and deposited in one chamber while larger trash and litter are forced into another. The device’s unique tumbling action serves the dual purpose of transporting the materials, while at the same time continuously cleaning the internal screens, thereby preventing clogging.

Servicing is recommended every 6-12 months to remove the captured contaminants and we offer a service agreement option with each Enviro G Series unit.

Water sensitive urban design

Growing environmental awareness has led governments and legislators to set new water quality standards and promote Water Sensitive Urban Design (WSUD). One of the aims of such initiatives is to encourage the removal of pollutants and other contaminants such as hydrocarbons and sediments from stormwater. The Enviro G Series gross pollutant trap (GPT), provides a fully compliant, simple, low-cost way of achieving this. In contrast to the conventional approach of multiple devices and pit inserts, the Enviro G Series centralises capture and retention of the full range of contaminants within a single unit. Typically one Enviro G Series unit is sufficient to service catchment areas up to 20,000 sq m. Not only is the Enviro G Series gross pollutant trap (GPT), easier and more straight forward to install, it takes up only a small footprint which means it can be conveniently positioned for ease of access and servicing.

Compliance and testing

Due to the wide variety in catchments, contaminants and water conditions, there are no universally accepted methods to measure the performance of Stormwater Quality Improvement Devices.

Design and testing of the Enviro E Series has therefore been based on recommendations in the Australian Run-Off Quality Guideline 2006 (ARQ) as well as recommendations from eWater, and in accordance with Water Sensitive Urban Design (WSUD) principles.

The unit’s processes have been tested via:

  • field monitoring
  • scaled model testing at University of Sydney
  • mathematical modelling and predictive analysis
  • University field data gathering and research
  • peer review by University of Western Sydney
  • full scale testing at Manly Hydraulics Laboratory


Field testing and monitoring

Stormwater Australia, as the national advocacy body have recently issued a draft protocol for the field testing and monitoring of devices that fall under the classification of Stormwater Quality Improvement Devices (SQID’s). In accordance with the high standard of compliance, Enviro Australis have engaged independent industry experts to implement the draft protocol entitled Stormwater Quality Improvement Device Evaluation Protocol (SQIDEP). This is aimed at augmenting field monitoring and testing already conducted.

Enviro G Series

Excavation Volume m3Maximum Pipe SizeTreated Flow
G301.7375 mm22 litres/sec
G453.3450 mm66 litres/sec
G606.2600 mm142 litres/sec
G7515.7750 mm258 litres/sec
G9017.81050 mm419 litres/sec
G12019.21200 mm900 litres/sec

Technical Specifications

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