Our project has reached a new milestone with applying the membrane contactor sampling system that is able to extract a huge amount of dissolved gases from groundwater in a sampling field trip. In October 2019, 18 boreholes in South Africa were sampled with this sampling system in order to collect gas samples for age determination with 39Ar and 85Kr.
One half of the sampled boreholes are situated near Cape Town, Western Cape, South Africa. Considering the sever water shortage most notably affecting Cape Town, it is important to increase our knowledge of the area, since this is an important fresh water source. The other half of the samples were collected in Northern Cape (Buffels River Valley). This arid region is strongly affected by salinization primarily driven by evaporative processes resulting in variably saline groundwater. The phenomenon is not fully understood yet, but it is evident that salinisation through evaporation is not the only driver in this regional system. That is why further investigation including our contribution is necessary.