Point Source Bailer
Point source sampling can be used to profile an open borehole or screened well, to collect samples from distinct levels or points of inflow. There is negligible disturbance as can be caused by pumping and purging. Mixing of the sample with water from different levels in the well is minimized.
Purging and disposal of purged water can be avoided, because sampling directly from a specific depth collects the water that has just flowed into the well at that depth.