With ever-increasing standards demanded for the effluent produced at wastewater treatment works, Southern Water is trialling a low carbon solution to use wetlands for wastewater treatment.

Described as one of the first projects of its kind in England, the water company’s wastewater treatment works at Staplefield will make use of a neighbouring field to create special areas of wetlands.

The shallow water and water tolerant plants of the wetland provide a unique filtration system, so that effluent leaving the works can be fed through it, before going back into rivers and seas.

Southern Water said that making sure that treated wastewater – or effluent - is clean enough to discharge into rivers and the sea is both challenging and costly and it needed to come up with a natural low carbon solution. The methods the company currently uses to remove phosphorous and other substances often require adding further treatment processes or using ferric dosing., benefitting the environment and the community.

Before deciding on the project, Southern Water made an assessment using its new risk and value tool, where the natural and social capital benefits are measured while considering the risk and the cost. The result is an innovative, nature-based solution which is also low carbon. Wetlands support about ten percent of all the species in the UK, so the benefits to biodiversity – and our community’s enjoyment of these types of wildlife – are clear.

.Marc Cottingham, Project Manager at Southern Water said:

“As a Civil Engineer working on lots of water and wastewater projects, I can see that using innovative and nature-based solutions like this one really is the future - and it’s the right thing to do.”