Data Requirements

Success Criteria



1.  Ability to sample a range of contaminants at site

Adequate sample volume for all analyses

Similar detection capabilities (as with low- flow sampling)


2.  Reproducible data

Analyte data for replicate samples

Among replicate samples, a %RSD of 25% or less, or equal to or better than that for low-flow samples

Yes for VOCs, dissolved inorganics, and total non- metal ions.

Testing problems occurred for some total metals analyses for both Snap Sampler and low-flow sampling

3.  Agreement between sampling methods for analytes of interest

Analyte concentrations for each sampling method for all wells

Lack of statistically significant differences

Lack of bias

Yes, except total Fe and total Mn, where testing problems limited determinations

4.  Reduced sampling time

Field records of activities at each well

Less time needed to sample a well


5.  Less costly sampling method

Records of the costs for equipment and supplies

Field record of technician’s time

Cost savings of at least 25%

Yes, 46%-67% cost savings


1.  Ease of use

Field records of activities at each well

Technician able to learn the procedure with relative ease


2.  Ease of use

Field records of activities at each well

Few problems requiring second attempt to sample the well

Yes (providing manufacturer’s directions were followed)

3.  Ease of use

Feedback from field technician

Operator acceptance