SDS Aqua-Xtract™ is a prefabricated CSO wastewater treatment system which provides a bespoke solution for preventing sewer litter from entering into, and polluting, watercourses and water bodies, whilst still providing the required hydraulic flood relief and guarding against sewer flooding in extreme rainfall events.

SDS Aqua-Xtract™’s removal of sewer litter pollution directly benefits Water Companies’ efforts to improve the quality and aesthetics of the natural water environment and helps counter any negative publicity whilst also reducing the risk of prosecution for a pollution incident.

Manufactured from Weholite HDPE plastic, SDS Aqua-Xtract™ represents a unique alternative to the traditional concrete CSO, by obviating the need for concrete inside or outside to provide structural integrity and thereby delivering multiple financial, logistical and environmental benefits to Water Companies and their appointed contractors.

How does it work?

SDS Aqua-Xtract™ comprises of a chamber, housing a sophisticated screen mechanism that skims solid waste from the sewer during flood conditions. Captured waste materials are diverted to the waste water treatment works for onward processing whilst the debris-free water is allowed to discharge according to the permit in force.

The structural integrity of the pipe relies upon its deformation from imposed loads to mobilise the support of embedment material on both sides of the pipe. Its primary structural function is distributing the imposed vertical loads to the surrounding soil; only a small portion of the imposed loads is actually carried by the flexible pipe itself.

When the soil is properly compacted around the pipe, the load-carrying capacity of the pipe-soil system far exceeds the individual capacity of either component by itself. As long as the installation of the pipe is carried out in the correct way and there is a sufficient cover (more than 0.8 m) above the pipe crown, the pipe can easily withstand highways loading.

The Weholite pipe and the enveloping soil mass, working in tandem as a composite unit, is one of the most remarkably synergistic systems in engineering.

With a typical weight, inclusive of pre-fitted steel components such as hydro-slides and penstocks, of less than 2 tonnes SDS Aqua-Xtract™ is light and easy to install.

The ease with which HDPE can be welded allows for exceptionally large chambers to be transported in unit sections and connected on site. Plastic’s flexibility also allows for minor alterations and additions to be undertaken on site with minimal disruption and costs.

For more information on how SDS Aqua-Xtract™ can protect your drainage network, call a member of the team now.

Download Data Sheet


Bespoke sizes.
Each CSO is manufactured to the specific requirements of the site.

Manufactured offsite.
Build quality and consistency of fit and finish are assured and superior to other production processes.

Light weight.

Estimated 2 tonnes’ average weight saving over comparable concrete system.

Manufactured from Weholite HDPE plastic.
Robust, excellent hydraulic properties and corrosion resistant.

Modular design.
System is supplied ready to use immediately upon installation and

Longer pipes and wider bores.
All sizes can be catered for, unlike with many other materials.

Delivery by section.
Avoids transportation issues and helps speed up installation and connection.

To discuss your CSO requirements please get in touch today.