Remediation: it's all in the technique
Using specialists in the field of geology, hydrogeology, chemistry, biotechnology and engineering, INEX Ground Remediation specialises in the treatment of contaminated land, using multiple remediation techniques to unlock valuable land for development. One project which illustrates the company's abilities is Oakfield in Ryde on the Isle of Wight. The site had seen several sorts of usage over the past century, ranging from a scrap yard, through landfill to a metal works. More recently, in the 1980s and 1990s, it was a brownfield site.
The site investigation performed by Inex produced a clear understanding on how the contaminants were present, where they were located and in what concentrations. The survey produced a three dimensional map of the contamination on the Oakfield site. The digging of trenches also produced information on the level of waste disposed of in the landfill area.
Fed by the information from the site survey, Inex engineers started their work on the design of the remediation proposal. Several tests were conducted on site to investigate the geophysical and geohydrological situation, to establish groundwater flow patterns, soil structure and ground bearing capacity.
The remediation techniques used by Inex included the excavation, sieving and removal of solid waste from the site. Hydrocarbon contamination in the soil was dealt with by biopiling and land farming, and active barrier treatment was used to deal with contaminants in the groundwater and perching water.
Finally, a clean 'living' layer with a special subsurface protective layer between the remediated ground and the clean living layer was applied. The active barrier was installed to deal with long term residual hydrocarbon and heavy metal contaminants, present in low concentrations, that could dissolve into the groundwater of hanging water and migrate from the site to the adjacent brook.
To make the site suitable for housing development, it was relevelled and equipped
with a clean living layer of one metre which was installed on top of the old
soil. In between the old soil layers and the new topsoil layer a special protective
zone was installed. This zone was charged with zeolites, a natural mineral with
high absorbing and fixing capabilities.