Southern Water is investing £7.3 million at one of its wastewater treatment sites to boost water quality in the River Ouse, to the north of Lewes.

The major upgrade projects at its Barcombe Wastewater Treatment Works site, north of Lewes, will help improve the ecology of streams feeding the river, cut storm overflows into it, and increase capacity to handle expected population growth in the area.

To date the water company has spent about £4 million on a system which removes phosphates from the treated wastewater. Phosphates cause algal bloom and lead to the choking of rivers and damage to the ecosystem and habitats.

Barcombe is one of 110 sites where Southern Water has added in this removal process for phosphates in recent years, in support of the Environment Agency’s work to prevent such chemicals, also including nitrate fertilisers, impacting river health.

The utility is also spending almost £2 million to build a new glass-coated steel storm tank, which will help the site cope when surface water overloads the network following prolonged rainfall events. The new tank will hold 300 tonnes of stormwater, before it re-enters the full treatment process when volumes drop.

This means that the capacity of the site has increased from the treatment of 20.8 litres a second to now being able to treat to 32.3 litres a second, both reducing storm overflows and allowing for expected population growth in the area.

John Penicud, Director of Wastewater Operations at Southern Water, said:

“There are many contributors to river health – including farming – but we know we have a key part to play too. We are investing in projects like this across the region to deliver real tangible benefits to customers and the environment.”