Southern Water plan to improve Isle of Wight wastewater plant approved

The Calbourne Wastewater Treatment Works — one of 20 on the Island — releases treated effluent into the River Caul Bourne which eventually runs into Newtown Creek nature reserve.

Under new plans from Southern Water — which were approved by the Isle of Wight Council earlier this month — an extension to the treatment centre on Middle Road will improve the standard of the effluent discharged into the environment and river.

The Calbourne works currently treats sewage from around 130 people but will now expand to accommodate more from the predicted growth in the area in the next 12 years.

The entrance to the Calbourne Wastewater Treatment Works on the Middle Road. (Image: Google Maps) (Image: Google Maps)

It is also being upgraded to comply with enhanced regulations by the Environment Agency over the levels of phosphorous in the water.

Phosphorous is found in wastewater — coming from human waste, foods, certain soaps and detergents — and in excess quantities can lead to water quality problems like harmful, toxic algal growth.

Southern Water will now be able to install new pumps and monitors to remove more phosphorous from the water so the quality of effluent released into the river would be better.

The proposed extension to Southern Water's Calbourne Wastewater Treatment Works. Picture by Southern Water. (Image: Southern Water)

The River Caul Bourne starts at the iconic Winkle Street, flowing down to the treatment plant before the water is joined by the treated waste and ends up at Newtown Creek.

One commenter told the Isle of Wight Council the proposals show best practices for sustainable urban drainage.

Construction of the expansion could take about a year, including 16 weeks of commissioning, mechanical and electrical installation and landscaping.

The Environment Agency requires the work to be completed by December 22, 2024.