Southern Water is nearing completion of a new concrete tank which can hold 600,000 litres of storm water –the tank will double the capacity of a Hampshire wastewater treatment works during intense rainfall.

The £2.4 million scheme at the company’s Petersfield site will help reduce the likelihood of storm overflows being required, when surface water overloads the sewer network during downpours and highly diluted flows have to be released into the environment to stop neighbouring homes from being flooded.

Instead the storm water will be held back in the tank, before being released for full treatment when levels drop.

The project also includes the installation of a new treatment process on site called ferric dosing, which reduces odours and phosphates, and extra oxygen has been added to the neighbouring River Rother in support of the local environment.

Ben Grogan, Southern Water’s project manager, said:

“Improving the health of rivers and seas is our top priority and the new storm tank and treatment processes will make a big difference. Our work at Petersfield is being replicated across our region in various forms, as we spend £3 billion between 2020 and 2025 to improve our performance.”

The storm tank was built by contractor GtB, who are also supporting Southern Water on a number of other key projects to treatment sites across its region including recently at our Portswood works in Southampton.

Andrew Dredge, Project Manager for GTb, added:

“We’re elated to see the new tank full of water already stopping spills to the environment. We have more work to do but are reaching the end of this project, one of many, in Hampshire, and Surrey, that we are working on.”