Project Dewatering support further development of Nine Elms
- Duration 8 months (ongoing)
- Value £200 000+
Project Involvement
The method proposed by PDL included a deepwell dewatering system that consisted of 16 no. wells around the 750m perimeter bulk excavation. The site’s water treatment system received pumped ground water and removed any contamination before discharge.
Introduction
The Nine Elms area has seen multiple large-scale construction developments in recent years. Project Dewatering Limited provided dewatering for the bulk excavation of this recent phase of work.
The site area had many previous uses, leaving the natural soil contaminated. PDL designed the dewatering system, supplied the installation and pumping equipment and then supported the client for many months to keep the bulk excavations dewatered.
The works
The method proposed by PDL included a deepwell dewatering system that consisted of 16 no. wells around the 750m perimeter bulk excavation. The wells were strategically positioned internally to secant & sheet pile excavation supports, to gain the required drawdown in the deepest excavations, while not interfering with other site works. These wells ranged from 10m deep to 15m deep and were drilled at a 250mm bore which was subsequently pumped using electric submersible pumps.
With this system, PDL could effectively achieve drawdown to about 2m below the formation level of the basement dig. The chemical analysis of the groundwater indicated high levels of petroleum hydrocarbons and organic chemicals. The site’s water treatment system received pumped ground water and removed any contamination before discharge.
