In low-yield wells is it advisable to use low-flow sampling?

On a practical basis, the limit for using low-flow in a well is about a 100 mL/min of well yield. You can go lower than that if you are willing to take the time necessary for purging. On a practical basis, if your pumping rate has to be much below a 100 mL/min or 10 L/min, it’s probably not practical to use low-flow purging and sampling in that application.  However, well evacuation is not really a great alternative because of how greatly it affects well chemistry. In those situations, I would recommend just sampling the water that is present in the well screen zone using some other methodology such as passive, no-purge, and minimum purge sampling.