Exploiting groundwater on a larger scale requires knowledge to be transferred more widely and effectively. Unfortunately, techniques for finding and exploiting groundwater are often hidden in scientific journals or project reports, and not widely disseminated. This manual aims to be a first step in providing useful information for project engineers working on rural water supply projects in sub-Saharan Africa. The focus of the manual is on low permeability aquifers, where groundwater is difficult to find. The techniques have been tested by the British Geological Survey for their effectiveness and by WaterAid staff for usability.