Demonstration/Validation of Long-Term Monitoring Using Wells Installed by Direct Push Technologies

Abstract : The objective of this study was to demonstrate that long-term groundwater monitoring results from direct push wells agree with those from conventionally drilled wells, the currently accepted baseline technology. Five field sites were included in the study to represent a variety of geological conditions as well as a cross-section of regulatory domains (e.g. EPA regions and states). Direct push wells were installed adjacent to, and paired with existing conventional wells, drilled via hollow stem anger. The following sites were part of this effort: the U.S. Army Corps of Engineers Cold Regions Research and Engineering Laboratory (CRREL) in Hanover, NH (EPA Region 1); Dover National Test Site (DNTS) at Dover AFB, DE (EPA Region 3); the Naval Facilities Engineering Services Center (NFESC) at Port Hueneme, CA (EPA Region 9); Tyndall AFB, FL (EPA Region 4); and Hanscom AFB, MA (EPA Region 1). Five sampling runs were conducted over a fifteen month period at each site. Target groundwater chemical analytes included the following volatile organic contaminants (VOCs): tetrachloroethene (PCE), cis-1,2-dichloroethene (cis-DCE), trans-1,2-dichloroethene (trans-DCE), vinyl chloride (VC), benzene, toluene, ethylbenzene, o,m-xylene, p-xylene, 1,4-dichlorobenzene (DCB)trichloroethane (TCA), and MTBE.