The Challenge
Urban and semi-urban developments often face constraints when it comes to managing surface water run-off. At this site, the shallow soils were clayey and unsuitable for conventional soakaway design, meaning water could not easily infiltrate at surface level. Traditional piped drainage would have increased flood risk and placed further strain on the local sewer system. The client therefore required a SuDS-compliant solution that would allow roof water to infiltrate safely into the ground.
The Solution
Our drilling team advanced a 30m soakaway borehole into highly permeable chalk beneath the clay. Once installed, the borehole was tested by rapidly introducing water to replicate a storm event. By monitoring falling test water levels within the borehole, we confirmed that the chalk could accept and disperse flows effectively.
The Outcome
The data collected enabled our client to:
Provide regulators with the necessary evidence to satisfy environmental planning conditions.
Incorporate robust geotechnical parameters into the foundation design.
Accurately estimate soil disposal costs by classifying materials in line with waste regulations.
With these critical risks and uncertainties addressed, the redevelopment can progress with confidence, ensuring both compliance and cost control.
