Low Flow Groundwater Sampling is the extraction of groundwater at ambient rates of around 25ml to 150ml/min. This is to ensure samples are representative of overall characterization of the groundwater.
Depending on the depth, size of well, and recharge rate different equipment can be used to conduct low flow sampling. The two main pumps used for low sampling is the Peristaltic Pump and Bladder Pump. Experience and knowledge dictate when to use a Peristaltic Pump and when to use a Bladder Pump.
The Peristaltic Pump is used when low flow sampling shallow wells of less than 27ft at sea level.
Bladder Pumps are used when low flow sampling of wells greater than 27ft is required as it is powered by a external compressor.