The background

Whilst NMCN refurbished the boreholes at Lambley BPS, their client asked them to provide compensation flow to Ramsdale Reservoir to ensure that the potable water supply was uninterrupted during the works.

The challenge

A duty point of 8MLD (92 l/s) @ 10.5 bar pressure was supplied and Selwood were asked to provide a suitable system that could comfortably deliver this including a standby pump that could run on generators as no mains power was available.

The solution

NMCN provided an inlet connection from the gravity main which runs from Ogston Reservoir and an outlet connection onto the pumped rising main from Lambley BPS up to Ramsdale Reservoir.

Selwood provided 4, 22kw WRAS approved vertical multistage booster pumps built up into a duty/assist/assist/standby arrangement utilizing WRAS approved fittings and materials. The interconnecting pipework between the connection points and pumps was blue HDPE pipework which was fusion welded by one of our in-house qualified installation teams. This was to ensure that the water in the pipework didn’t leak out and wouldn’t be contaminated by any external factors.

Control and monitoring of the equipment came in the form of 4 30kw inverter control panels, ABB magflow meter with data logger and Selwood clarity remote monitoring system which allowed for web-based monitoring of the system including live flow data. Initially a temporary power supply was used in the form of duty/standby 150kva generators with an automatic change over panel. Upon further review by the client a suitable mains power supply was found and the equipment was changed over to mains power, this provided the client with a cost saving and emissions saving as the generators, which were running 24/7, were no longer needed.

All telemetry signals provided by the Selwood system were supplied to the client for them to connect into their E-Scada system allowing for the end client to receive these remotely.

The result

Compensation flow to Ramsdale reservoir has been maintained and the client has run the system continuously throughout the works being carried out.