The Background

Affinity Water has invested heavily in an upgrade to one of its Hemel Hempstead sites, which serves potable drinking water to thousands of homes in the area. The work was carried out by nmcn as the Principal Contractor. Crucial to the upgrade were significant essential works to the pumping station – and the need to maintain supply to customers while the works were being carried out.

The Challenge

nmcn invited Selwood to an initial meeting to discuss how the pumping station could maintain its operation while the works were undertaken. Any solution needed to comply with stringent drinking water regulations while ensuring the upgrade works could continue without interference. It was also important to provide a sampling point to ensure consistent water quality, and to protect the installation against any efforts to tamper with the drinking water supply.

The Selwood Solution

The traditional solution when a pumping station is out of commission is to import water from other areas to keep supplies flowing to customers.

However, Selwood’s engineers with input from nmcn believed there was a better, more resilient solution that could achieve the objective with far less expense and disruption while maintaining the required flow rates and pressure. The team developed a containerised pumping system that effectively replicated the setup that was inside the station. This duplicated the pumps and monitoring equipment, including the inlet and outlet flow pressure meters, sensors, water quality sampling function and communication and alarm switching.

This was effectively a plug and play solution – the temporary system was just set up, secured and connected to the existing pumping station inlet. The unit was completely locked down to avoid the possibility of tampering for the six months it was in operation.

The Result

Selwood’s solution saved the significant time and expense of routing water from elsewhere to cover the period while the pumping station was out of action, plus there was no loss of resilience of supply. The works proceeded without issue and without disruption to the water supply for customers.

The self-contained unit developed by Selwood for this project can be easily adapted and applied to clean water projects anywhere in the UK, providing a cost-effective, secure and safe method that can be deployed for other similar projects.

The Feedback

Chris Leary – Project Manager nmcn said, “Selwood provided a collaborative service that listened to our requirements for the project and provided nmcn with some options. We were then able to sit together and discuss a way to move forward to meet with cost and programme on the project.

Selwood were able to meet with the tight programme needs and delivered the pumping station on time. The installation team were competent and diligent. Selwood have always been amenable to site visits to understand the project constraints and to work with nmcn to provide a solution to the problem. I would be happy to use Selwood on any of my projects again in the future.“