What is the purpose of purging a well?

Purging a well serves the critical function of ensuring that the water samples collected are representative of the groundwater in the aquifer rather than being influenced by stagnant water that may have been sitting in the well casing. When water sits in the well for an extended period, it can become stagnant and may not accurately represent the quality of the groundwater. By purging the well, technicians remove this stagnant water, allowing fresh water from the aquifer to flow into the well, thereby obtaining a sample that is more indicative of the actual conditions present in the groundwater.

The action of purging typically involves pumping out a certain volume of water before sampling takes place. This process helps to eliminate any contaminants or anomalies that may have accumulated in the water that was standing still in the well. As a result, the samples taken after purging provide a more accurate assessment of the groundwater quality, making it an essential step for effective well monitoring and management.