Andre
I would be concerned about air ingress into the sample.
Not sure I would expect to see a correlation between PID and chemical tests either . Look at limit of detection of PID and the likely vapour conc for the SSTL.
Steve
Sent from my iPhone
> On 15 May 2014, at 01:21, Andre-Karl Smit <[log in to unmask]> wrote:
>
> Hi All
>
> To cut a long story short, we have a regulator reviewing a project of ours that wants soil vapour sampling of stockpiles – by driving a probe into the stockpile, attaching a summa vapour canister to the free end and drawing a sample for VOC analysis. The reasoning is that although we had a soil SSTL (for TCE, which was based on the soils not being able to generate unacceptable soil vapours), he was still not convinced of the soil results (which are below SSTL) due to a poor correlation between PID and soil concentrations, and wants additional data.
>
> Has anyone ever carried out anything like this, and if so, some comment on whether it works or not? I have some concerns over the representativeness of "soil vapour" results from stockpiled material.
>
> Kind regards
> Andre Smit
> Principal Consultant
> GHD Sydney
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