The project and why was it needed?
This upgrade will significantly improve the removal of nutrients from treated wastewater leaving the site, helping to protect and improve water quality in the River Yeo as it flows through Yeovil.
Pollutants such as phosphorus and ammonia from sewage that arrives at the centre can cause harm to plants and animals in our rivers.
Often found within agricultural fertilisers, farm slurries, septic tank discharges and domestic wastewater, these pollutants can cause large growths of damaging algae in streams and rivers, which deplete the amount of oxygen in the water – a process known as eutrophication.
Capacity to store storm water before it is discharged to the river has also been significantly increased to more than 5.5 million litres – nearly double its previous limit – allowing us to hold more water back for later treatment and safe return to the environment.
What did we do?
The enhancements, which have taken two years to complete, followed several years of planning, design and preparation work, and construction started in October 2022.
Testing and commissioning of the new equipment on site is continuing to the end of 2024.
Project Manager Dave Thomas said: “By dramatically increasing our storm storage at Pen Mill, we’ll be able to really make a difference when it comes to the quality of water discharged to the river.
"The excess water can be contained in the larger storage tanks before being pumped back to the front end of the site for treatment.
“This refurbishment also ensures we will continue to meet the highest environmental targets for removing pollutants such as phosphorus and ammonia from sewage that arrives at the centre.’’
Local benefits
The Yeovil project is also helping to further enhance local ecology, with a dedicated habitat for reptiles being created at the western end of the site, housing more than 70 slow worms that were discovered prior to the preparation work for the site enhancement.
Tree planting and the location of bird and bat boxes are also being completed at the centre.
What else are we doing?
The project continues our hefty investment in south Somerset which has seen similar work carried out at Ilminster (£7 million), Martock, Crewkerne, Merriott (£12 million), Hardington Mandeville (£6 million).
Just over the border in Dorset, upgrades have also taken place at Sherborne (£4 million), while planning approval is being sought for a £7 million enhancement of the centre in Halstock.
It is also the latest part of more than £400 million of investment being poured into upgrading the region’s water recycling centres between 2020 and 2025.
Find out more
We have ambitious plans to make our largest ever investment in water and sewerage services of more than £3.6 billion.
This investment will improve the health of rivers, reduce pollution and create an additional 700 jobs – plus thousands more in the supply chain between 2025 and 2030, subject to approval by regulators.