SOUTH West Water has reduced storm overflow spills at one of its top-spilling sites in Devon after relining over 100 metres of sewer.

In 2024, the storm overflow at Dulford Sewage Pumping Station in the village of Dulford near Cullompton was one of the highest spilling sites across the region.

Thanks to targeted improvements, which included relining 134 metres of sewer and sealing 11 manholes, the number of spills fell by 53% in 2025.

The cause of the problem was groundwater infiltration - water that exists underground in cracks and spaces in soil, sand, and rock.

In Dulford, this water was entering the sewers through gaps in joints and flowing into the treatment works.

In villages like Duflord this extra water can overwhelm the sewer network during periods of wet weather, leading to spills from storm overflows.

To tackle this issue, South West Water’s teams carry out CCTV surveys to identify sections of pipe affected by this infiltration.

The affected areas are then cleaned thoroughly so that the lining material can be pulled through the pipe and laid in place. The lining is then cured inside the sewer, creating a watertight seal.

Engineers complete follow-up CCTV surveys to confirm the lining has set correctly and no water is getting into the network.

Jenny Eamer, Operations Manager for Dulford, said: “Groundwater entering sewers might not be visible on the surface, but it puts real pressure on our system during wet weather.

By relining pipes and sealing manholes, we’ve strengthened the network, reduced spills, and protected the environment.”

Dulford formed part of South West Water’s £16 million Infiltration Reduction Programme, which targeted 175 high-risk sites after reviewing performance across more than 1,600 storm overflows.