In September 2020, the sudden appearance of sinkholes at one of our drinking water storage tanks in Kent triggered a chain of events and challenges which many across the business and beyond have not experienced before, and may never again.
The voids compromised this important site which holds treated drinking water before it’s pumped to customers’ taps, and their appearance was an immediate safety and water supply risk.
Immediately following their appearance the site was switched off resulting in our operational teams working swiftly to reconfigure the drinking water supply network ensuring homes and businesses continued to receive water.
With the safety of our teams being top priority, in the days following the incident our engineers worked closely with experts from across the country, including specialists from Kent Fire and Rescue, to make the site safe, assess the situation and monitor the site for further ground movement.
Neighbouring homes, businesses and organisations were kept up-to-date with the situation on site which involved working closely with partners including the Kent Resilience Forum.
A wide range of specialist surveys were undertaken from CCTV, geophysical, laser scanning ground level monitoring and dynamic probing to understand what is happening under the surface.
External drone surveys were also regularly undertaken to monitor the ground with specialist drones and remote operated vehicles used to inspect within and beneath the tanks.
Once the initial surveys were complete work began in earnest to bring part of the site back into operation ahead of the peak 2021 summer demand period.
During the winter months teams from all across the business worked alongside specialist contractors to undertake the complex repairs required to bring the site back to life.
The work included filling the voids with 1,800 cubic metres of foam concrete with a further 2.4 tons of resin injected beneath one of the tanks to support the structure.
In March 2021 their hard work paid off as one of the site’s tanks began supplying customers once again.
“The effort that’s gone into getting part of this site back up and running by our target date has been monumental. The ingenuity, collaboration and effort displayed by both our staff and all the contractors involved proves how agile and passionate we, as a business and industry, are. Our teams went to extraordinary lengths to keep customers supplied while all this was going on in the background, and that can’t be underestimated.” Douglas Whitfield, Operations Director
Although part of the site is operational again, our dedicated engineers are continuing their efforts to repair the remaining tanks on site, in the hope that they can also supply customers again in the future.
The team has also joined forces with Vistry Homes which has a site nearby to create a joint surface run-off system to provide future protection.
To build further resilience into the area’s network, teams are also building a temporary water treatment works nearby which will bolster supplies while repairs continue. It’s hoped this facility will be up and running towards the end of summer 2021.
Throughout all this intense work the health and safety of our staff and contractors has been top priority with the site has remaining Covid-19 compliant throughout without a single case recorded.