Ecosol Net Tech

The EcosolTM Net Tech (in-line/end-of-line primary treatment solution) is a robust pre-screening net filtration system for use where there are cost or space constraints. It captures more than 91% of solids larger than 19mm.

Key features

The EcosolTM Net Tech is a robust and modern filtration system for use where there are cost or space constraints, or specialised cleaning equipment is not available. The unit captures and retains more than 93% of solid pollutants larger than >600μm, although, in practice, it has been found to collect much smaller particles, including fine sediments.

Easily installed, into most drainage networks the unit’s simple design has a net release mechanism that eliminates any adverse hydraulic impact traditionally encountered with direct-screening trash racks. It can be installed not only end-ofline at almost any pipe outlet but also in-line where concrete structures such as manholes and junction boxes can house the unit. It is also a cost-effective and efficient pre-screening system for vegetated swales, wetlands, and on-site detention systems.

The EcosolTM Net Tech consists of a stainless-steel sleeve extension that is fitted into existing, or new, outlets, and a removable polyethylene net, which, when full of pollutants, disengages during a rain event, effectively eliminating the risk of flooding during peak-flow storm events. The unit is easily cleaned using a small crane truck for lifting the net and emptying the pollutants.

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Dimensions and Holding Capacities

The EcosolTM Net Tech will treat 100% of all flows in both free-draining and submerged environments until the net becomes full and disengages from the main unit, effectively eliminating the potential for flooding. Independent testing has found that the unit has little, or no, impact on the hydraulic performance of the drainage network.

The holding capacity of the EcosolTM Net Tech varies with the site specifics, including the outlet type and size. The holding capacity is designed to maximise the life-cost benefit to the asset owner. The unit’s design enables it to achieve its maximum holding capacity without adversely affecting the hydraulic design characteristics of the drainage network.

The following table (table 1) shows the EcosolTM Net Tech dimensions and the holding capacities for typical cylindrical pipe and box culvert outlets.



1 The pipe diameters listed are internal pipe diameters.
2 The box culvert lengths (also commonly known as culvert span) and heights refer to the internal dimensions - box culverts are available at various heights up to the nominated culvert dimension.
3 Dimensions listed are fir single units on single inlet pipes or culverts, for multiple inlet pipes or larger units please consult with you local EcosolTM representative.



Particle Size Distribution Collection Efficiency

In order to determine a meaningful characterisation of the products collection efficiency, an extensive testing and verification phase was undertaken by Avocet Consulting Pty Ltd, Ecosol Pty Ltd and EngTest (The University of Adelaide).

To best summarise the capture efficiency results of extensive product testing a regression of the data points using a sigmoidal regression curve was selected as it provided a conservative fit to the wide scatter of data collected. Refer to figure 2 for results of 50mm netting tests. Table 2 summarises these results.


  Table 1 - Summary PSD collection efficiency’s based on field and laboratory testing data.  
  Figure 1 – Field Particle Size Distribution Results.  

Figure 2 – Plot of collection efficiency sigmoidal regression line for the 50mm laboratory netting tests.

Pollutant Removal Efficiencies


Table 2 – Suggested collection efficiency for the 50mm netting EcosolTM Net Tech products.

1 The optimal collection efficiency for the EcosolTM Net Tech is at approximately 30 – 60% full. Accordingly, the removal of the constituents is dependent on the composition of the particles, and the bonding of the chemical constituents to the surface of the particles. Additionally the particle filtration performance of Net Guard is dependent on the body of pollutant forming a media already captured by the filter; therefore conservative capture efficiency ranges have been provided.

Quoted Capture Efficiency (CE) values are intended as a general guide only, please consult with your Ecosol representative for site specific product sizing and modelling.


Treatable Flow Rate

The EcosolTM Net Tech will treat 100% of all flows in both free-draining and submerged environments until the net becomes full and disengages from the main unit, effectively eliminating the potential for flooding. Independent testing has found that the unit has little, or no, impact on the hydraulic performance of the drainage network.

The tables below provide an indicative guide of the products treatable flow rate relevant to pipe sizes and gradient. With an empty filtration net the resistance is negligible and therefore the treatable flow rate is higher. However when the filtration net is full of pollutants and impervious the Treatable flow rate of the unit approaches zero at which point the unique release mechanism will disengage the next thereby enabling full pipe flows to continue without any hydraulic impact.


Figure 1 - Treatable flow rate for the EcosolTM Net Tech as a function of pipe diameter for a circular outlet conduits.

Headloss (K Factor) and By-pass Capacity

Headloss is defined as the hydraulic energy loss (embodied by the pressure reduction) experienced by the flow through the unit as a function of the flow rate through the unit. Testing by the Urban Water Resources Centre (The University of South Australia) confirmed that the release mechanism is constantly triggered before any significant build-up of pressure behind the filtration net. In all cases the maximum head recorded was only 54mm above pipe obvert.

In summary independent testing has found that the EcosolTM Net Tech has little, or no, impact on the hydraulic performance of the drainage network. Unlike other in-line/end-of-line systems, the unit’s unique release mechanism ensures there is no obstruction to flows in critical storm events, effectively eliminating the risk of flooding.


Cleaning and Maintenance

One of the key advantages of the EcosolTM Net Tech is that a small crane truck can easily lift full filtration net for emptying. This eliminates any risks associated with manually handling captured pollutants. As the EcosolTM Net Tech is predominately installed as a dry system there is a reduced likelihood of captured contaminants causing any significant adverse environmental impact or nuisance (such as odors and putrefaction).

The key benefit of this primary treatment device is its low capital cost along with its low ongoing cleaning and maintenance cost.

Catchment Size and Recommended Cleaning Frequency

As with all filtration systems, the EcosolTM Net Tech should be cleaned regularly. The cleaning frequency, and the cost, depends heavily on the surrounding environment, the unit’s proximity to a waste facility, its location, and the type of pollution it is designed to capture.

A key benefit of this primary treatment device is its low capital cost along with its low ongoing cleaning and maintenance cost. The EcosolTM Net Tech can be easily inspected visually to determine whether it needs cleaning. EcosolTM recommends the unit is inspected every two months or after any major rain event to determine if it needs to be cleaned. Cleaning is recommended before the filtration net reaches its capacity to avoid flows bypassing the unit and discharging untreated stormwater to the receiving waterway. The figures below give a broad guideline about the catchment size and the number of cleans required annually.



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  Table 1 – Indicative maintenance frequencies for the EcosolTM Net Tech

1Cleaning frequency is based on typical gross pollutant loads anticipated for standard commercial, residential and light industrial catchments. Gross pollutants in this instance includes vegetation as well as anthropogenic litter, however excludes sediment. Cleaning frequencies may vary based on local catchment conditions and rainfall however the above theoretical cleaning frequencies are based on a pollutant loading of 40kg/ha/year.

All data provided in the above tables and figures are based on single units with 2.0m net lengths. For multiple module units or open channel applications please consult with your local Ecosol representative.



The EcosolTM Net Tech is usually installed end-ofline at pipe and box culvert outlets ranging in size from 300mm to 1500mm, although pipes and box culverts can be fitted with multi-unit configurations.

Typically, the unit is located at single drainage outlets that discharge to beaches, rivers and creeks. The EcosolTM Net Tech is also often installed in-line in its own concrete pit in a manhole or junction box as long as the unit is not obstructing flows. In these cases it has the added benefit of being underground and, therefore, visually unobtrusive and ensuring that captured pollutants are stored safely away from the general public. It usually operates as a dry system but can be installed in tidal and submerged environments where it will not, under any flow condition, remobilise captured pollutants larger than the filtration net apertures.

The EcosolTM Net Tech is an effective primary pre-screening system that removes larger solids from stormwater, thereby extending the life of secondary and tertiary treatment systems, such as wetlands and vegetated swales, which would otherwise become clogged with gross pollutants.







Net Tech Multi Unit Applications

The EcosolTM Net Tech can also be configured to suit multiple outlet headwall or discharge points to beaches, rivers, creeks, and open drains where flows are usually of greater magnitude than those conveyed conventionally by single pipe systems and where the multi-unit EcosolTM Net Tech is suitable in preference to more-costly and larger high-end engineered GPTs.




Net Tech Channel Applications

This systems has been successfully installed as a first flush treatment system for open channel or canal applications. The EcosolTM engineering team is able to provide a comprehensive design proposal which includes preliminary hydraulic, structural and total concept design including access and hard stands for maintenance. This turn key service is the catalist for its success as every critical element is considered in the preliminary design and tender process. If success full EcosolTM can then fabricate, install and maintain the system specific to the clients needs and site application.



Ecosol Net Tech



Ecosol Net Tech Installation Guides

EcosolTM Net Tech Face Fit - Installation Guide

EcosolTM Net Tech Insert Fit - Installation Guide

Ecosol Net Tech Maintenance Guide

EcosolTM Net Tech - Maintenance guide

Ecosol Net Tech Technical Specifications

EcosolTM Net Tech - Technical Specifications

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