Correct Bailer Technique
To obtain an accurate sample using a bailer, just follow these basic steps:
- Gently lower the bailer down the groundwater well column. Do not let the bailer crash into the water table. This will cause agitation and turbidity through surging and the sudden impact of the sampling device.
- As the bailer approaches the water level within the well, be sure to ease the bailer into the water table for the first 3-6 inches of the bailer length. The recommended rate of descent for this step is 5 to 10 seconds.
- Once the bailer has been gently lowered into the water table, allow the bailer to descend to on its own until it fills. Do not allow the bailer to descend to the very bottom of the well. If the bailer comes in contact with the bottom, it could disturb the sediment that may be settled at the bottom of the well. This will also cause turbidity within the well and your sample.
- Once the bailer fills, retrieve the bailer from the well slowly, in a steady, smooth motion. It
is neither necessary nor recommended to jerk or jig the bailer line.
By utilizing this method, sampling with bailers will significantly reduce agitation and turbidity. Taking only 1 to 2 extra minutes, you will retrieve accurate groundwater samples in a cost-effective and timely manner.