Major upgrades take shape at wastewater site

It's hoped a giant storm tank will help halve the number of wastewater releases into part of the River Itchen.

Southern Water's building it at its Portswood treatment site in Southampton after concerns were raised after readings taken earlier this year by Friends of Itchen Estuary found E.coli levels near St Denys were 34 times higher than what's acceptable for bathing water status.

Due to be completed by next September, it's part of £8million worth upgrades there.

Work began in February and aim to improve the quality of treated final effluent entering the chalk stream.

On a dry day, the site treats over 15 million litres of wastewater from Southampton – but this total can more than quadruple when it rains and surface water runs into the company's sewers.

So far during the works, teams have added a new treatment process on site called ferric dosing, reducing odours and phosphates, and have been adding extra oxygen to watercourses to support the local environment.

The company aims to complete the constuction of the new storm tank by September 2025.

The River Itchen, and its neighbour the Test, are renowned across the world for their chalk stream habitats, and annually attract a population of Atlantic Salmon to their waters.

John Penicud, Managing Director for Wastewater, said:

“We’re keen to play our part in improving the health of this much-loved chalk stream and its Atlantic Salmon population, and that is why we are investing in major upgrades to our Portswood site.

“We are one of numerous guardians of water quality in this area, led by the Environment Agency, and we support a shared aim of creating bathing waters or ‘blue spaces’ in the lower Itchen. Only by working together can we achieve the progress we all want to see.”