The WASTAP sampling system is used for obtaining samples of both water and gas at certain depths, without the problems of cross-contamination.
Click here to download the WASTAP sampler datasheet.
The WASTAP is pushed to the desired test level using standard 36mm diameter CPT rods or 55mm diameter casing rods. At the test level the WASTAP is pulled back enabling the filter to be opened. Then sampling can commence.
The WASTAP system provides two methods for water sampling. One where the sample is pumped up to the surface, the other where the sample is collected in a container within the sampler.
In the first method an electrical or hand-operated vacuum pump is used to pump the water up to the surface from the test depth through a silicone hose. The maximum test depth is restricted to about 8m below groundwater level.
In the second method a 0.5 litre container is used. At the desired test depth the container is lowered into the WASTAP and locked into position. Then the filter is opened and sampling commences. There is no restriction for the test depth.
In unsaturated soils gas can be sampled either by pumping it up the same way as water or by letting it escape by its natural pressure. The samples are recovered in membrane-sealed containers for subsequent laboratroy testing.