Preston Unsatisfactory Intermittent Discharge (UID) Scheme
Preston, United Kingdom

KMI Water, a joint venture between Kier Infrastructure and Overseas, J Murphy & Sons Ltd and Interserve Construction Ltd undertook a £114 million sewer improvement scheme for United Utilities. The scheme involved the complex construction of 13 large diameter shafts, installation of 4.5km of tunnel, 9km of rising main, screens chamber, pumping station and outfall, plus associated manholes and pipework, designed to upgrade the area‘s ageing sewer system.

The project was part of United Utilities’ overall unsatisfactory intermittent discharged (UID) scheme. A 3.5km long, 2.75m internal diameter section, some 30m below ground and part of the 4.5km tunnel is for storm-water storage and holds up to 40 million litres of water to prevent overflows discharging into the River Ribble.

PERI used a variety of systems to construct the terminal pumping station at Penwortham, which lifts flows from the tunnel and transports them to the waste water treatment works at Clifton Marsh.