Passive, No-Purge Samplers Services

Furthermore, traditional and low-flow sampling methodologies have inherent uncertainties associated with them. Does purging a well many times truly allow you to collect a “representative” sample? Is a purging method truly repeatable from one event to the next? How does exposure of the collected sample to the atmosphere affect accuracy? Data quality is critically important. After all, we use the data to select remedies and use data trends to determine their effectiveness.

Fortunately, new passive, no-purge, groundwater sampling approaches are now available. They are easy to implement and limit waste generation. Moreover, passive methods reduce long-term monitoring costs. Of course, it is imperative that the sampling technology selected does not compromise data quality. A passive device that seals samples in situ is an ideal way to save money and actually improve long term data quality and repeatability.

ProHydro, Inc. is the developer and manufacturer of the Snap Sampler® groundwater monitoring device. The Snap Sampler is a passive, no purge, groundwater sampler that seals your sample downhole, right in the container that you send to the laboratory for analysis. You collect groundwater samples in an undisturbed condition, without pumping, dropping a bailer, yanking on a string, or relying on diffusion to capture a proxy sample.

The Snap Sampler uses double-ended sample bottles, which you set in an open position and deploy in the screen zone of the monitoring well. At the time of collection, the field scientist uses a trigger at the well head to close and seal the Snap Sampler bottles with zero head space. You then retrieve the sealed bottles and send them to the laboratory. In fact, the laboratory can place the 40 ml VOA vials directly into the auto-sampler for subsequent analysis. The groundwater sample is never exposed to the atmosphere.

You can set the Snap Samplers downhole in series using any combination of 40ml glass, 125ml HDPE or 350ml HDPE bottles, based on your analytical requirements. As mentioned above, you do not purge the monitoring well when Snap Sampling. Natural ambient flow-through in the screen zone of the well provides fresh formation water to the device.

Multiple studies, including a Department of Defense ESTCP Demonstration/Validation project and testing by the University of Waterloo and others, have shown the Snap Sampler compares particularly well with traditional volume-based purge sampling and low flow sampling methods. The studies demonstrate that the Snap Sampler improves data quality and repeatability. It is easy to see why, as you collect samples the same way, at the same position in the well, in a sealed container during every sampling event. The method removes variable field conditions, such as wind and temperature, as sources of data error. Further, because your sample is sealed before you remove it from the well, you virtually remove data variability due to field crew practices.

Snap Sampler Facts:

• No purging, no waste generation
• Representative, highly repeatable data generation
• Sealed-in-situ, zero head space, groundwater samples
• Sample 15-20 wells a day
• Test any analyte
• Low cost