In a race against regulatory deadlines, Grundfos has delivered critical bespoke pump systems, to strengthen Severn Trent Water's clean water resilience and avert potential supply interruptions for millions of customers.
The situation
Grundfos has helped in the successful delivery of two clean water resilience projects for Severn Trent Water in a very tight timeframe. The water company was seeking to strengthen its clean water supply network by augmenting the fill capability at Ragdale Reservoir with serves customers in both Leicestershire and Derbyshire, UK.
Both projects involved the design and engineering of bespoke mobile booster pump systems to support the work of Severn Trent’s Network Response Team (NRT), which is responsible for quickly addressing water supply issues and ensuring that customers have water restored as quickly as possible.
The first project, which took place at the village of Stanford on Soar, near Loughborough, builds resilience at Melbourne water treatment works (WTW), securing protection against the risk of catastrophic failure of the works. Melbourne is the second largest WTW in Severn Trent’s area of operation, providing some 250Ml/d of water to customers in the Midlands.
The solution
Grundfos is Severn Trent’s framework supplier for vertical multistage pumps. On this occasion, the requirement was for a total of six Grundfos CRN 255-2-2 vertical, multistage centrifugal pumps, installed across three adapted shipping containers and operating at 55kW.
Once connected and working together, the three pairs of pumps would provide a total 485l/s duty at 35m head.
By contrast, the second project, which took place at Hare Edge in Derbyshire required three Grundfos CRN 95-8-2 pumps housed in a single container. The requirement in this case was for a lower flow of 185l/s of water with a higher head of 85m, also operating at 55kW per pump. In total, the Hare Edge project involved installation of three containers, with three pumps in each.
Grundfos is Severn Trent’s framework supplier for vertical multistage pumps.
“What is amazing to me is the flow and head our design engineering team has achieved on two different sites, with two completely different pump configurations. This gives Severn Trent a mobile, highly flexible solution, which has multiple advantages. “These bespoke containerised pumping systems mean there is no need for permanent pumping stations for these critical applications that will rarely, if ever, be used. They give the water company and their customers the necessary resilience, while mitigating the complexities and cost of planning permissions, and of constructing and maintaining permanent facilities”
Both mobile pump systems were designed and engineered by Grundfos’s specialist team at the company’s manufacturing and design facility in Sunderland, UK. The compact portable nature of the systems required intricate design to ensure all components, including pumps, pipes and control panel, could fit tidily into a single container.
A total of six control panels was required across the two projects - one for each container – to control the operation of the pumping system, chlorine and turbidity monitoring, along with heating and lighting. Three control panels for the Stanford on Soar site were supplied by Nottingham-based Blackburn Starling, while the final three for Hare Edge were produced by Grundfos in-house to meet the pressing timeline.
While each booster pump system was built for use at the specified site, they will be stored at Severn Trent’s Minworth site in Sutton Coldfield and are flexible and mobile enough to be moved around the Severn Trent network where need arises.
Agile assets
The work represented a scaling-up of earlier projects undertaken in partnership with Severn Trent’s NRT, where mobile booster sets were housed in modified commercial trailers for deployment in the field.
Given the need for agile assets for potential use under emergency conditions, safe transport of the units was a major consideration. An essential aspect of the design was that there was no risk of damage to the equipment during loading and unloading of the roll-on roll-off trailer.
Prior to installation, the booster sets were put through a stringent hazard and operability (HAZOP) study organised by WISP Global, the engineering consultancy overseeing both projects, which took place over a five-hour period.
HAZOP is a structured and systematic method for identifying potential risks and problems in a process or system. It is used to evaluate product and equipment design and identify potential deviations from the intended operation that could lead to health and safety issues or inefficiencies.
One issue identified by this process, and subsequently addressed by Grundfos’s design engineering team, related to manual handling of the piping equipment onsite. It was decided that the pipe inlets and outlets on the four containers should be lowered to reduce the manual lifting of pipes, given their size and weight.
Along with the Grundfos design team, this requirement was accommodated by S Jones Containers, the company responsible of modifying the four containers, which included installation of doors along the length of the containers to improve accessibility.
Tight timeframes
The tight timeframe for completion was a major challenge across the project, with a requirement for the works to be finished by the end of March 2025 to meet the water company’s regulatory asset management plan (AMP7) delivery expectations.
Deep collaborative engagement between Grundfos, Severn Trent Water and WISP Global ensured the deadline was met.
“These critical clean water projects have been delivered in line with our strategy for long-term operational resilience. Not only will they help ensure uninterrupted supply at the two specified sites, but the assets have great potential for use elsewhere in the network. This mobility and flexibility means they can be transferred from site to site as need arises, to manage other reservoir sites and planned works, or where there’s a sudden pipe burst and risk of loss of service to customers.”