Anglian Water Services – Integrated Operational Solutions
Caistor Resilience Scheme
A collaborative project between Panks and Anglian Water’s Integrated Operational Solutions (IOS) means Norfolk residents in the Caistor St Edmunds area can rest assured their water supply is secure for years to come.
A £280,000 contract saw Panks design, manufacture and install a resilience scheme to provide a back-up water supply to the Caistor network in response to a major problem which occurred in 2014.
At Christmas time, in 2014, a break in the output main at Caistor St Edmund Water Treatment Works, left over 4500 homes without water for two and half days before the supply could be re-established.
Local authority Anglian Water working in alliance with IOS partner Kiers, needed to implement a resilience plan in the contingency of another such emergency – and that’s where Panks were called in.
Tristen Allen, Project Engineer for IOS, a delivery arm for Anglian Water said: “I knew Panks could deliver. I had no hesitation in recommending them. Panks were immediately the preferred option. I’ve had a good rapport and working relationship with the Panks team for over 5 years and had no hesitation in fully entrusting the project to them. They have never let us down.”
A High Priority Water Supply Resilience Scheme
The project was high profile: it was the first major collaborative project since IOS was established in 2015 and, due to its very nature of ensuring the delivery of potable water to thousands of homes, a high priority in Anglian Water’s outcome delivery index.
Contractor Kiers, employed Panks to implement the solution: using an existing efficiency connection rising main between Caistor Water Treatment Works and Norwich’s Lakenham Storage Resevoir and to design and install a resilience philosophy and reverse pumping system.
In the event of a further breakdown in the water supply to Caistor, the resilience application will reverse the flow along the rising main, flush out the pipework via a wash-out at Caistor and test for potable water quality before bringing the resilience pump online to reverse the flow and supply the water tower at Caistor.
Project Details
The scope was to utilise an existing 450mm diameter rising main between Caistor and Lakenham and to supply, manufacture and install a dedicated variable controlled resilience pump at Lakenham with all
necessary mechanical and electrical systems to pump potable water 7.5 km to the Caistor network in case of another breakdown.
The required flow rate of 110 litres per second, @ 6.7 bar was provided by Anglian Water. After an initial inspection in August 2013 Panks commissioned a hydraulic analysis of the rising main to inform project planning and design.
After using smooth pipeline conditions for modelling, the survey showed the existing rising main could be expected to withstand the required total dynamic head of 67, but that in the event of an unsuppressed pump shutdown, the resulting pressure surge could be severe and thus the installation of a surge vessel was required.
Panks supplied and installed a stainless steel surge vessel with compressed air pump to buffer any radical surge in pressure, along with a rapid acting spring assisted pump check valve.
Panks engineers designed a variable controlled resilience pump to be operated in the event of another output breakdown at Caistor, therefore allowing precise regulation of the water flow and pressure from Lakenham to Caistor. A Motor Control Centre was installed to accept the new control philosophy.
The dedicated pump and Control Panel was housed in the existing pump gallery at Lakenham. Additionally 20m of 316 stainless steel pipework was installed to link the two output mains.
Challenges
The project was not without risks and challenges; the existing water supply to houses in the Caistor and 
Lakenham designated zones had to be maintained throughout, requiring modifications to the existing systems and pump sets.
The project needed to be turned around extremely quickly with 14 weeks from hydraulic analysis to completion of the works. The installation was operational in time for Christmas 2015, which must have been a welcome relief for local residents.
Andrew Powley Panks Engineer said “We tested and commissioned the system in January 2016 and we
were extremely happy with the results. We feel our first major project working with the collaboration of IOS was a big success. As the project is one which directly supports AWS’ impact plans for taking good care of customers, we can feel especially happy and proud to have been integral to this process.”
Tristen Allen, project Engineer at IOS is similarly pleased with the outcome: “These works were very critical to us. As a first major project for IOS in collaboration with the team at Panks, we all worked together and successfully supported each other.
“We’ve kept all our customers happy; residents in the Framlingham/Loddon area, the site owners at Caistor and Lakenham and Anglian Water’s Central Project Team. It’s a shame we can’t show the system off – but the security is knowing it’s there in case it is ever required. You know with Panks that they are there for the duration. The guarantee of quality remains; they are always available and willing to help long after the job is complete and they have left the site.”
