What can be considered deep groundwater?
In general, handpumps cannot be used below 40m. Below that depth, the weight of the pipes become to much and the pipes can break. To avoid such regular breakdowns, the pipes must be supported. However, the pump cylinder is not installed at the static water level, but at the dynamic water level. The dynamnic water level during pumping is normally 5 to 10m. below the static water level.

Water levels change with time
During pumping the waterlevel in the borehole goes down and can be 5 to 10m below the static waterlevel. In addition to this lower level, in the dry season the regional groundwater level may also go down. In brief, the depth of the cylinder should have a 'safe margine', which is basically the sum of pumping drawdown and other groundwater fluctuations, so in general at least 10 to 15m. below the static water.

Therefore in areas with a static groundwater levels between 25 and 30m. deep, the safe installation depth of the cylinder is about 40m. Water levels deeper as 25m. should therefore be considered as 'deep groundwater zones' as far as it concerns to handpumps.

BluePump Bottom Support solution
When handpumps cylinders are installed below 40m. the main technical problem is caused by the weight of the pipes filled with water. With the India VLOM pumps, these pipes eventually break and leak. However, the BluePump comes with a a "Bottom Support" system, in which the rising main pipes are not hanging on the top, but continue until the bottom of the borehole. This avoids stress on the pipes and contributes to the life span of the PVC pipes.

The BluePump Bottom Support (BS) system enables pumping from 100m deep. With the installation rope, the installation up is also easy and can be done by 2 persones only without the need of a tripod or additional installation tools.