Watchgate Water Treatment Plant

Watchgate Water Treatment Plant near Kendal is United Utilities clean water treatment plant for Manchester’s water supply from Thirlmere and Windermere.

On site a 54,000 litre, 12% sodium hypochlorite tank was contained by wooden bunding which would not have been effective in the event of a spill. The Health and Safety Executive specified that bunding effective and compliant with best practice should be installed.

To meet best practice for chemical storage , an impermeable bund was specified of 110% capacity of the tank (58,000 litre) using an LLDPE liner compatible with up to 15% concentration of sodium chlorite. stored. (See chemical compatibility charts

A bund of 64,000 litre size to contain the 58,000 tank was specified using modular 3 ft containment walls. This construction has a proven track record and exhaustive testing to withstand the pressures of liquid stored. (See Engineeers testing on fluid retention and hydrostatic pressure report).

The modular bund is quick and easy to install on the tarmac surface at Watchgate and as a modular constrcution can be easily relocated which is likely for this tank.

During installation records of the liner were kept and the welds of the liner were sample checked by site tensometer.