As one of the leading performers in the UK Water industry Bournemouth & West Hampshire Water provide clean drinking water to around half a million people in an area of over 1000 square kilometres.

To meet growing needs, a new slow sand filter was required, essentially a large reinforced concrete tank, 60 x 45m and 3m deep. Designed to BS 8007, the concrete frame was designed by Structa with the minimum amount of joints to provide the most cost effective solution. A naturally high water table required careful investigation and consideration to ensure that the design was optimised whilst safeguarding against flotation, including the design of temporary drainage below formation level.  This allowed for the structure to be as light as possible, saving on concrete quantities and reducing deliveries for the large concrete pours.

Our structural design also needed to take account of the ongoing maintenance which is undertaken on a continuous cycle, by removing and recycling the sand layers to remove impurities and ensure a continual delivery of clean water to customers.  This required the design to cater for vehicle loading and ensuring that items which required removal were designed for manual handling or included lifting points.