The installation and equipment for the screening method is by far the simplest and also the cheapest method for soil water sampling. This means that it is possible to install more sampling points and get an idea about the horizontal distribution of pollutants in the unsaturated zone. This technique is suitable in most soils with a grainsize up to medium grainsize sand in a depth range of 0-5 m below surface.
The installation is presented in the figure above, and the procedure for installation can be downloaded here (link til pdf). Each sampling point consists of:
- A porous water sampler (e.g. PRENART SUPER STEEL).
- Tube (e.g. FEP).
- Silica flour to ensure hydraulic connection between sampler and unsaturated zone.
- Collecting bottle (e.g. polypropylene).
- Customized bottle cap (e.g. Srew cap (POM)).
As shown in the figure above we also add sand (e.g. standard filter sand for installation of groundwater wells) and bentonite. The purpose of the bentonite is to avoid surface water to reach the sampler and the sand in use to avoid bentonite from blocking the fine pores in the sampler. After installation, vacuum can be established by using e.g. the portable vacuum pump.
The equipment we supply is prepared and tested for vacuum purposes, to ensure that the bottle does not collapse, and risk of leaks minimized. For each specific project, it is however important to evaluate which specific sampler, tubes and bottles that are most suitable. Our specialists listed below can help you selecting the best options for your project. We can also help install the probes and all parts of data interpredation, risk assessment etc.