Thames Water 'shells' out less on waste costs thanks to invasive wetlands mussels

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Mussel shells

Bags of mussels arriving at the Walthamstow reservoirs

An eco-friendly team at a Thames Water nature reserve came up with an innovate way to save money and cut down on waste by recycling unwanted mussel shells. 

 

More than 35 tonnes of quagga and zebra mussel shells, which are found in huge numbers and cost millions of pounds to remove, were crushed and used to create four new tern rafts during a conservation project at the award-winning Walthamstow Wetlands in North London. 

 

Site manager Dan Brackley enquired about reusing the mussels, which were removed from the nearby Coppermills Stream, to save on the cost of building materials and disposing of the shells. 

He said: “These invasive non-native species are already present in all of our reservoirs as well as the rivers and underground tunnels. They can cause blockages and, as well as the cost of resources required to remove them, our treatment works can be affected while cleaning work is carried out. 

 

“By using them like this, they can instead become a new tool for us, as this material can be used for future work on site, such as laying pathways and in filling potholes.” 

 

Since 2006, Thames Water has spent almost £4 million clearing the mussels, which latch on to the inside of pipes and tunnels, removing the equivalent of four Olympic swimming pools full of shells. 

 

During its latest clean, the 700m Thames U-tunnel, which runs from the High Maynard to the East Warwick reservoir at Walthamstow, contained a staggering 1,374 tonnes of the mollusc.  

 

New habitats for the site’s important birds, such as shoveler and gadwall, were made During the conservation project, including the creation of a “beach’” area and the planting of wetland seeds. The new tern rafts made from the mussel shells and floating islands were also installed on the Banbury, Lockwood and East Warwick reservoirs. 

 

Rebecca Elliott, Thames Water’s senior ecologist, said: “Developing innovative solutions to managing invasive non-native species is important to us. 

 

“The solution we found here benefits the wildlife at Walthamstow Wetlands while removing the need to take waste to landfill, reducing our energy and carbon footprint and creating a new and sustainable environment, as well as saving the business and our customers’ money by reusing a material already present on the site.” 

 

Nadia Ward, conservation volunteering officer at the site, added: “Wetland habitats are extremely rare in urban areas and, as such, it is of great importance to protect the future of Walthamstow Wetlands. 

 

“It is with the support of the public and partners that dedicated conservation work can continue and improve the site for many more generations of wildlife and people to come.”