I have spent most of my career with small and medium sized ground investigation / geotechnical specialists, and one of the benefits of how we work has always been that the geotechnical engineer writing a report for us is the same engineer that was on site or in the lab logging the soil from the boreholes. On most projects we usually have some shallow sampling, using something like a window sampler or other drive-in sampler, or some trial pitting. This might be a couple of days work to provide good coverage and it makes sense to have a geotechnical engineer on site logging the boreholes and directing the work as information is gathered. Clearly if we are drilling say ten boreholes in a short timeframe we want to make sure they are put in the best locations, and that can only be achieved by having the engineer on site. With deeper boreholes, drilled using cable percussion or by rotary coring, where progress is slower, it is generally more practical to provide part-time supervision and to keep in touch with the lead driller by phone.
Juliet Fuller, Associate Director at GEA, recently attended Environment Analyst’s annual Groundwater conference. Here, the updated approaches to the risk assessment and management of PCBs and other emerging contaminants in groundwater were discussed. For those unable to attend, Juliet recaps the key learnings covered during the conference, and outlines why we should all take note.
In the mid-1980s, a site in the East of England suffered a significant leakage of the chlorinated solvent Perchloroethylene (PCE), causing land and groundwater pollution. Because the density of these kinds of solvents is greater than water, they tend to sink in groundwater systems, resulting in complex plume patterns which can make leakages such as these difficult to remediate.
At GEA, we are increasingly called upon to provide independent advice in respect of piling problems. Here, Martin Cooper - Technical Director at GEA - looks at some of the recent piling challenges we’ve been helping our clients to solve.