AGI Universal Sampler - Representative Results For Passive Samplers
| Performance Objective | Data Requirements | Success Criteria | Results |
|---|---|---|---|
| 1. Equivalent analyte detection limitis | Detection levels for all AGI and low-flow samples. | Detection levels near or below EPA’s MCL values for all contaminants tested. | APG site: The MDL for AGI sampler was below the MCLs. However, it was ~20x > low-flow MCL. Pease site: For most analytes, MDLs equivalent to low-flow. MDLs were 10x < MCLs. |
| 2. Equivalent analyte concentrations to low-flow sampling | Analyte concentrations for each sampling method for all wells | Lack of statistically significant differences at p <0.05 | APG site: Significant differences for several analytes. Pease site: Generally no significant differences; poorest agreement for benzene and xylenes |
| 3. Comparable concentrations across the entire range of analyte concentrations present | Analyte concentrations for each sampling method for all wells | Linear least fit model shows linear relationship with a slope that is not significantly different from 1.0 | Both sites: Significant linear relationships between the AGI and low-flow data, with a slope = 1.0, for all analytes except TCA and CF at APG and toluene at Pease. |
| 4. Ability to measure vertical profiles within wells | AGI results from all depth intervals tested. | Vertical profile of wells with AGI Sampler | Vertical profiles revealed. Pronounced concentration gradients in wells near plume epicenters, even in a well with a 5 ft screen. |
| 5. Cost savings | Records of the costs for equipment and supplies Field record of field crew’s time |
Cost savings of at least 25% | APG site: Cost savings of 18% to 35%, depending upon the size of field crew. Pease site: Cost savings of 10% to 25%, depending on size of field crew. Both sites: Cost savings of 30% to 40% using recent price quote for samplers. |