Rapid Gravity Filter Replacement

  • Project Rapid Gravity Filter Replacement
  • Principal Contractor Severn Trent Water
  • Key Benefit MGF’s industry knowledge allowed for extra care to be taken in the planning stage to avoid disturbance of the water main running near the site
Above shot of MGF kit installed in an excavation


Long-standing clients Severn Trent Water were tasked with the refurbishment of six Rapid Gravity Filters (RGF) in Bamford, Derbyshire, as part of a £5 million design and build contract.

Contractors Stantec Treatment (formerly MWH Treatment Ltd) put forward a case to build two brand new RGF’s rather than refurbish the six filter systems currently in service. Stantec demonstrated it’d be considerably cheaper and would provide an improved service.

Excavator digging into the ground
MGF struts installed onsite
An above look at a fitted excavation with sheets and struts

The Solution

The solution required a 11.85m x 33.8m x 4.56m deep cofferdam following a local 2m ground reduction. Land boundaries, hard ground/rock level, weight restrictions and the disruption of other underground services were all stand out elements to consider in the design.

Extra care was taken during the planning of the excavation to avoid the disturbance of a water main running just 2 meters away from the edge of the site.