A contractor on Dunstable Road hit a buried chalk solution feature last March. Three days of delays while they figured out if the footing design still worked. The borehole log said one thing, the ground truth another. That gap between point data and the continuous subsurface picture is exactly why we run electrical resistivity surveys. A vertical electrical sounding array maps how resistivity changes with depth, flagging transitions from clay to chalk, pockets of saturated sand, or dissolution zones before the excavator bucket finds them. In Luton—a town shaped by the Cretaceous Chalk Group and capped with variable Quaternary deposits—geology can shift within a single site. The Lea Valley drift and Clay-with-Flints make for unpredictable interfaces. VES gives us a non-invasive cross-check, reducing the number of boreholes needed while tightening the ground model. Our team has applied this method on sites from the airport industrial corridor to the slopes near Wardown Park.
A resistivity profile costs a fraction of an extra borehole and catches lateral changes that point sampling simply cannot see.
