Envco – Environmental Equipment

The goal of groundwater sampling is to collect samples that are “representative” of in situ groundwater conditions and to minimize changes in groundwater chemistry during sample collection and handling. Experience has shown that groundwater sample collection and handling procedures can be a source of variability in water quality concentrations due to differences in sampling personnel, sampling procedures, and equipment (U.S. Environmental Protection Agency, 1995).

The collection of “representative” water samples from wells is neither straightforward nor easily accomplished. Groundwater sample collection can be a source of variability through differences in sampling personnel and their individual sampling procedures, the equipment used, and ambient temporal variability in subsurface and environmental conditions. Many site inspections and remedial investigations require the sampling at groundwater monitoring wells within a defined criterion of data confidence or data quality, which necessitates that the personnel collecting the samples are trained and aware of proper sample collection procedures
Field testing shows that groundwater sampling with the Snap Sampler is faster and less complicated than pump sampling. No power is needed and no separate devices are needed to determine purge stability, turbidity, or water level fluctuations. Laboratory and field testing of the Snap Sampler show consistently encouraging results. Blank Snap Sampler bottles are clean and sealed in the same container as an Encoretm soil sampler.

Cost savings using the Snap Sampler is commonly 50%. Some sites even exceed that amount. With no waste to dispose (not even extra sample waste), very little preparatory logistics, and simple operation, sampling 20 wells per day should be expected. Improving productivity by 100% or more is the primary driver for cost savings, along with avoidance of waste handling and disposal.

Another driver for cost-savings is reduction in field sampling variability. Reduction of sampling random error from 30% to 10% can make the difference between seeing a trend and not. Demonstrating remedial effectiveness or natural attenuation in many cases is more important from a cost perspective than the sampling itself. All sources of savings should be considered when evaluating overall cost of a groundwater sampling program.

Snap Sampler bottles have special end caps made of PFA Teflon. The end caps are constructed to attach to a Teflon-coated internal closure spring and to an outer release mechanism. The 125ml or 350ml POLY bottle also seals in situ. The plastic bottle can be used for larger volume sample needs, metals or other analytes where a plastic bottle is preferred. For non-volatiles, this bottle can be opened at the well head to combine in a larger bottle, transfer to a glass bottle (e.g. for SVOCs), or just to remove the internal spring before acidifying a metal sample.

Snap Samplers with 40ml and 125ml bottles fit in 2-inch or larger monitoring wells. Snap Samplers with 350ml bottles fit in 4-inch or larger monitoring wells.
Bottles are available in 40ml VOA vial size in glass; or 125ml and 350ml sizes in plastic. The 40 ml VOA vial can be used directly in standard laboratory autosampler equipment. The sample is never exposed to the open air from the well to the gas chromatograph.

Ordering Information
Snap Samplers
PH40 (40 ml) Plastic (Acetal) Snap Sampler
PH125 (125 ml) Plastic (Acetal) Snap Sampler
Stainless Ball Fitting Connector Cable (to connect between multiple Snap Samplers; appropriate number included with Snap Sampler purchases)
Plastic-end, FEP-coated connector cable

Light Duty Trigger
Trigger Construction Trigger line per meter

Heavy Duty Trigger (for deployments deeper than ~40-60 feet/ 15-20 meters)
Trigger Construction Trigger line per meter

Electric Trigger (for deployments deeper than ~100-150 feet / 30-50 meters)
Downhole Electric Actuator
Electric Trigger Line Construction Plus cable trigger line per meter

Well Head Docks
2-Inch (5-cm) Dock (ProHydro well cap plus support ring)
4-Inch (10-cm) Dock (ProHydro well cap plus support ring)
Custom Dock

Bottles
Package of two 40 ml Snap Sampler VOA vials, includes septa caps and labels
Package of one 125 ml Snap Sampler POLY bottle, includes septa caps and label

Tool Set (includes two driver tools, one nipper tool, Standard Operating
Procedure, laminated instruction cards, and tool storage tote)