Gross Pollutant Trap (GPT) Systems

Gross Pollutant Traps (GPTs)

Gross Pollutant Traps (GPTs) are large treatment devices designed to capture litter, debris, and coarse sediment from stormwater before it enters the wider network or receiving environment. Common GPT systems include Cascade Separator™, CleansAll®, Downstream Defender®, CDS®, First Defense® and Ecosol®, Vortcapture™ Vortech™ - each playing a critical role in protecting waterways and downstream treatment assets.

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Our PRocess

1.

Complete all health and safety paperwork.

2.

Pre-start meeting, hazard Identification, confined space entry permit, job safety analysis.

3.

Dutton Stormwater will remove all the sediment, litter and vegetation using a vacuum truck.

4.

We remove all the spent media from the modules and wash the modules down completely.

5.

We vacuum the chamber once more.

6.

We replace the media with fresh media.

7.

Polluted waste is disposed of at an approved environmental disposal facility.

8.

We send the customer and council (if requested by the customer) a full report of the service.

How GPTs Work

Stormwater enters the GPT and either passes through internal screens or baskets or utilises a vortex system that captures and separates gross pollutants such as litter, leaves, plastics, and coarse sediment from the stormwater. Treated stormwater then exits the device and continues through the stormwater network. By intercepting larger contaminants at this early stage, GPTs help protect downstream treatment devices and support the overall performance of the stormwater system.

Why Maintenance Matters

Regular maintenance is essential to keep GPTs operating effectively. Over time, captured litter and sediment can build up within the device, reducing storage capacity and performance. If maintenance is delayed, blockages may occur, increasing the risk of bypass, flooding, and pollutants being discharged to the environment. Routine servicing ensures the GPT continues to meet performance expectations and consent requirements.

Professional GPT Maintenance Services

Dutton Stormwater provides professional GPT maintenance services throughout New Zealand. Our team inspects the device, removes accumulated litter and sediment, cleans internal components, and confirms the unit is functioning as designed. Due to the size and depth of many GPT’s, maintenance needs to be carefully planned and typically requires confined space entry, which is carried out by our specially trained technicians under strict health and safety protocols. All recovered material is disposed of at approved and certified waste disposal facilities.

Recommended Service Frequency

GPTs are generally serviced every six to twelve months, depending on catchment characteristics, land use, and pollutant load. Following each service, we assess the condition of the GPT and provide a tailored maintenance recommendation within your service report to support long‑term asset performance and compliance.

Extend the lifespan of your GPT

Get in touch with us today and Schedule your regular maintenance.

Trusted by councils & leading enterprises.

Hear it from our clients

    
 
 
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   hani albarni 
 
 
 
 Trustindex verifies that the original source of the review is Google. Amazing culture amazing team to work with 👌🏻
  
 
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   theresa coleman 
 
 
 
 Trustindex verifies that the original source of the review is Google. It was a comedy of errors dropped keys down storm water, then dropped grill trying to retrieve the.Kat and Grant saved the day. You guys rock!!
  
 
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   Commercial Realty Limited 
 
 
 
 Trustindex verifies that the original source of the review is Google. The Property Management Team here at Commercial Realty use Dutton Stormwater for our commercial portfolios stormwater maintenance requirements. They have excellent customer service, fair and competitive pricing and great communication right through to beginning to the end of the job. We highly recommend Dutton for all stormwater maintenance services!
  
 
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   Lisa Wilson 
 
 
 
 Trustindex verifies that the original source of the review is Google. Excellent customer service right from the start of my enquiry.  I'm very happy with the job completed (cleaning of stormwater detention tank and cesspits) and with the service by each team member who I had contact with throughout the process.
  
 
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   Cameron Hicks 
 
 
 
 Trustindex verifies that the original source of the review is Google. Great!

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Gross Pollutant Trap (GPT) Systems

Gross Pollutant Traps (GPTs)

Our PRocess

How GPTs Work

Why Maintenance Matters

Professional GPT Maintenance Services

Recommended Service Frequency

Extend the lifespan of your GPT

Trusted by councils & leading enterprises.

Hear it from our clients

Stay in the know with the latest from Dutton Stormwater.

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