A water treatment works was suffering at the hands of freshwater zebra mussels in its pipelines. Zebra mussels are an invasive species that arrived in the UK around 200 years ago. They are thriving as a result of the UK’s water cleanliness and millions are now playing havoc with pipeline supplies. When this particular works increased pipeline flow to meet summer demand, it would send Zebra Mussels cascading down to the pump-house strainers, blocking the pipeline and forcing the plant to close for 36 hours to lift out the strainers and remove the shells. To get a handle on the extent of its problem, the plant called WRc.
WRc used its Sahara® acoustic umbilical system along a 400m section of the 900mm diameter pipe between the reservoir and pumping station – a section known to be providing a favoured habitat for the zebra mussels. The profile of the pipe produced by Sahara® showed live zebra mussels attached to the top of the pipe, obscuring almost the entire top half, while an approximate 6” pile of dead shells could be seen on the bottom of the pipe.
As a result of knowing the extent of the problem, the treatment works can now plan accordingly and artificially increase the flow when convenient, out of peak periods, flushing zebra mussels down to the strainers. Zebra mussels have a five-year lifespan, so occasional visits from WRc are helping to keep the situation in check.